# LP gas configuration to melt gold



## yazeed

Recently in looking for an alternative gas configuration to melt gold and also seeing the disadvantages of the blowtorch to melt gold,a shopkeeper advised me on another alternative to a handheld gas device.It uses normal LP gas canisters with a torch attachment with a claim of reaching 1800°c,so guys do u think this arrangement for melting gold would work and how long would it take in minutes to melt a small average button


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## butcher

yazeed, Lp can be propane or butane or a mix of these liguid petroleums, I will speak of propane here:
propane can get hot enough to melt gold, some of things to consider is what gold is being melted in, if open air and melting dish and a torch heat is lost to surrounding airand even the dish, also what dish sets on can act as a heat sink to absorb heat, furnace refatory can absob heat some types more than others, but refactory surrounding can also help to contain the heat and reflect heat back as radiated heat (a double edge sword), also a furnace has the ability to give you better control of the enviroment of the melt (oxidizing or reducing atmosphere), the burner (or torch if used) will also make a big difference, there can be a dramatic differenc in their construction, how well they burn fuel with air, flame character, and heat produced and type of flame they make, also burners can be desighned to run at different gas pressures, some are assisted with blower's providing more air (and fuel for hotter temp), some burners may also be desighned to convert liquid fuel to gas (heated coils at burner head, with some fuels like propane or fuel oils), well we could go on and on, hand held propane torch is very useful with what we do, but lack the heat needed in my opinion for melting gold outside of a furnace, hand held torch flame can also be small compared to furnace burners, but if I was wanting to melt gold with propane a furnace in my opinion is needed, and a burner that fits furnace size .these can easily be built with scrap yard material, a little welding skill and refactory, burners are also easily made, or these can be purchaced, to me they are so easily made I cannot see no reason to buy one. 
backyard metal casting, propane burners, propane furnace, and like terms will lead you to much information on google, also these have been discussed many times here on the forum and pictures are here on the forum of different desighns, as well as induction furnace discussions.
hope this helps some.


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## yazeed

will check that out butcher,thanks for the advice


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## gimli

I have found that I can melt gold with a handheld torch using MAP gas. If I switch to propane (same torch head and crucible, etc) I cannot get it hot enough. 
If I, however, place the crucible in my furnace and use the handheld with propane, I can melt the gold. The furnace is a simple "peach can" style furnace but a little bit bigger with the addition of a small round 1/2" thick firebrick in the bottom on top of 1" of Kai wool. The sides and too are,1" wool as well


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## saadat68

Hi 
I want to use LPG in gas cylinder for melting silver 
Can someone check my homemade torch before I use it ?
Is it completely safe ? :? 

I added a flashback too but it didn't work so I remove it. Is it safe without flashback?

Thanks 

http://uupload.ir/files/r0fd_img_20170809_203925.jpg

http://uupload.ir/files/6ikw_img_20170809_204110.jpg
http://uupload.ir/files/sfap_img_20170809_204204.jpg
http://uupload.ir/files/lr95_img_20170809_204222.jpg


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## anachronism

saadat68 said:


> I added a flashback too but it didn't work so I remove it. Is it safe without flashback?



Did you put it on the right way round?


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## saadat68

Hi
Yes, all of flashbacks here are for acetylene gas or oxygen. I use acetylene flashback but it didn't work 
Maybe LPG doesn't need flashback?!
Is it dangerous ? 

http://www.gcegroup.com/files/images/Product%20Images/INDUSTRIAL/FBA/80910_Oxygen_80950_Fuel_SG2_MV93_hose_thread_torch.jpg

Edit: 
I find this in web:
https://www.quora.com/Why-dont-we-provide-flash-back-arrestors-for-cooking-gas-cylinders



> Whereas, in the case of Cooking, flash backs will not occur. Here, LPG is in pressurized form, whereas the oxygen (in atmosphere) is at the atmospheric pressure. Hence, there is no possibility of oxygen or explosive mixture entering LPG cylinder. So, a Flash back arrestor is not necessary for a cooking gas cylinder.





> When you perform oxy-fuel cutting, both the oxygen and fuel gas cylinders are pressurized. Flash backs are commonly caused by a reverse flow of explosive mixture (of fuel gas and oxygen) through hose into either fuel gas cylinder or oxygen cylinder.
> 
> Hence, we provide flash back arrestors for gas cutting operation.


But we use blower instead of oxygen cylinder. Can a blower blows air in gas cylinder? For example when pressure in gas cylinder is low?


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## butcher

I have worked on industrial burners (boilers) (with many different fuels), and been in the welding trades, and worked on many different types of appliances that use either natural gas or propane.

But when it comes to propane burners, and what we should need to know about them, especially when dealing with safety,  I am no expert, so take what I have to say, with caution concerning this matter. 

I have built many of my own small burners for my personal use.

My thoughts on this (take with grain of salt)]:
With a propane (or natural gas) if the burner is properly designed there should be no need for the flashback arrestors.

In a torch that is a totally different matter, I would use flash back arrestors. The torch (cutting or welding has a different design and it works differently and the conditions are very different from burners. 

Acytelene will explode if pressurized (not sure at what pressure but somewhere above 15 PSIG), With a much higher oxygen pressure, and a mix of acetylene and oxygen and the back pressure of a flashback or sustained back fire, in the torch you can be standing next to a bomb trying to melt a little gold. so use flash back arrestors and check valves on your torch.

Propane under Normal working pressure does not explode (like acetylene will) it can be compressed to a liquid, as that is what is in your tank (the liquid under pressure drops to a lower pressure environment in your burner to become a gas(actually gas fill the small volume of the tank inside but lets not get too technical here).

In a properly designed burner, the propane is forced through a small diameter orifice (very small hole say a # 56 or #62 drill for example) the gas flows into a stream of air (from a blower or from the venturi effect of the burner itself) or even a stream of oxygen. The burner is not really under much pressure (even with a blower, (compared to a torch and its design). So the likely hood of mixing fuel and oxidizer (in the gas line or in the tank) is not likely to happen (my opinion only). If it did get oxygen or air into your tank I do not believe there would be much of a problem (again keep the salt handy). 

As far as burn back or flash back in the burner, here any safety device would never be a bad idea.
But I really cannot see the burn back entering the fuel line or the tank through the orifice in the burner design (torches again is a totally different story). 
A flashback is different than a sustained burn back or backfire.

For a moment lets discuss torches (I may get back to the burner).
In A torch: 
Most of the causes for a flashback or a burn-back (back fire) are normally operator error, using the torch wrong (overheating), damaged (seats), loose or leaky fitting or damaged parts in the torch.

Burnback or backfires are normally less dangerous (than a flashback) the burning back of the flame inside the torch tip (Loud popping or snapping noise) as the flame goes out, will rarely get past the mixing valve to (create a flashback).

The Flashback can be much much more dangerous! here the flame (similar to small high-pressure explosions) burns back past the mixing valve (sounding like squealing pigs, or hissing snakes) as the flame pops out the torch tip spews clouds of black sooty smoke, if you get flash backs something is seriously wrong with the torch (need repair of faulty condition) or it is from how you are using it (overheating, too close to work, using wrong pressure setting...).and as mentioned earlier with acetylene it becomes explosive somewhere above 15PSIG (note the red line on yer gauges).

The burner (of course this depends on the type, but for what burners most all of us on the forum would use) is much different from the torches we use.
The burner will not suffer the same issues, as the torch.

My recommendation is Always Use check valves and flashback arrestors on your Torches.
Although a flashback arrestor and a check valve could never hurt and would be a smart safety feature, the flash back arrestor is not totally necessary on a "properly designed burner.

Now saadat68,
As far as your burner and what I can tell from the picture, I do not see any obvious safety issues.
But as far as the design I see some things I would change, (they may not be needed as I have not used or tested it), (so again we may need some salt, with my words), the delivery pipe looks very long (may or may not be a problem, but I feel the pipe from the blower should be bigger in size (you want a good volume of air, and little restriction, (maybe even sizing it as big or bigger than the fan blower outlet).
The galvanizing (zinc coating) from galvanized pipe (if that is actually what you are using) is a big NO NO, Zinc burns and oxidizes easily and emits white spider webs into the air. I have had night sweats chills where you feel like you are dying from welding on Zink coated steel (galvanized steels). Use black iron pipe.

I am no expert by far, and only can go on what little I know or believe, so take it for what it is worth (not much), do your own research. just my own opinion on the matter.
My safety is in my hands, and your safety is of yours, my friend.

A few Tidbits on propane, I would look for more myself and study as much as I could on the matter.

https://gashosesandregulators.com/propaneregulatorfacts.php
http://www.harrisproductsgroup.com/en/Expert-Advice/Articles/Flashback-Arrestors.aspx

Propane approximate vapor pressure of liquid at various temperatures:
-20 deg. F ----10 PSIG
0 deg. F ------23.5 PSIG
+20 deg. F ----40.8 PSIG
+70 deg. F ---109 PSIG
+ 110 deg. F---197 PSIG

Note also the more volume of gas delivered from the tank the colder the tanks get( multiple burners, large burners long use time a large volume of flow), it is not uncommon for the tanks to freeze or develop a frost from the refrigeration effect of the liquid changing to a gas (high-pressure liquid to a low-pressure gas) where it may be necessary to sit propane tank in heated water or use a heater blankets...


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## saadat68

Thank you very much butcher

I got these from your post:

1- Burners and torch are different. So burners don't need flashback arrestors but a torch such as welding torch needs.

2- The burner is not under much pressure even with a blower so there is no risk that oxygen goes in gas tank. Also you think there isn't any problem if oxygen goes to propane/natural gas tank 
(Even gas proportion in tank is 5 or 10 percent and pressure is low?)

3- burn does not back entering the fuel line or the tank through the orifice in the burner design (Likely I added a suitable nozzle in the pipe. Is it in the right place? )


As butcher isn't contain that his post is fully correct I need someone confirms his and my posts 

Thank you


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## niks neims

saadat68 said:


> I added a flashback too but it didn't work so I remove it. Is it safe without flashback?
> 
> Thanks



Had a similar problem with my oxy/propane setting, after getting back to the shop where i bought some of the parts, mechanic took a look at my setup and turns out problem was very simple - the reductor (regulator?) on my propane tank was wrong kind - giving out enough pressure for propane stove (where it was originally from) but not enough for my brand new torch setup (not enough to pass flashback arrestor), i got a new reductor (relatively very cheap) and my torch worked beautyfully, actually melted my first button today .. . Will try to upload pic tomorrow  

Anyhow my advice is to solve flashback arrestor problem, oxy/propane flame is suprisingly powerfull, one can only marvel at the awesome power contained in those two little tanks...


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## saadat68

Thank you niks neims

You use oxygen too but I don't. I use blower instead it also as butcher said propane does not need flashback arrestor. I couldn't find arrestor for propane, all of them are for acetylene and oxygen.
Something is wrong. :? 

I go to shop today. hope to solve problem with another regulator


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## butcher

Try a larger (air pipe) blower pipe or burner pipe, for the fan size you have.
Check the orifice size (fuel hole size) for propane (try drill number #56 to #60).

Check (pressure regulator) for burner size.
Try 0-20 pound propane adjustable regulator.

https://propanewarehouse.com/shop/propane-regulators/adjustable-propane-regulator-0-20-psi/


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## saadat68

butcher said:


> Try a larger (air pipe) blower pipe or burner pipe, for the fan size you have.
> Check the orifice size (fuel hole size) for propane (try drill number #56 to #60).
> 
> Check (pressure regulator) for burner size.
> Try 0-20 pound propane adjustable regulator.
> 
> https://propanewarehouse.com/shop/propane-regulators/adjustable-propane-regulator-0-20-psi/



I can buy this: 
http://www.avijehsanat.net/Images/Original/0257c8c8-1986-4a99-a479-9b5a2b7fa40b.jpg

It is 0-3 bar
3 bar = 43.5 psi 

*P max of flashback arrestor is 1.5 bar. No problem ?
What happen if regulator set in 2 or 3 bar? Does flashback arrestor work In this condition? ( these regulator don't have any gauge )*


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## butcher

I am having some problem understanding the comment or question, things get lost in translation.
And I am also trying to get into my head the conversion of these pressures (bar pressure is unfamiliar to me).

Bear with me here.

1 Bar = O PSIG (pressure we read on gauge) = 1 atmosphere (pressure of the weight of air all around us) = 14.69 PSIA (absolute pressure, most people do not read on gauges) = 101.3 kPa ...

1.5 bar = 21.75 PSIG(gauge pressure).
2 bar = 29 PSIG (gauge pressure). 
3 bar = 43.5 PSIG ( as you so well put it).

OK now that I have that solved in my head lets see if I may be of any help.

First make sure the regulator is for propane, regulators are made for specific gases, specific density, and internal parts of the regulator can be very different for different gases or liquids...
Using the wrong type of regulators can be very dangerous.

A drop of oil in an oxygen regulator or even on oxygen fittings can cause an explosion, many types of pipe sealants use oil, so on oxygen the sealant or even tape should be made for use on oxygen.

You most likely will not go over around 20 PSIG (< 1.5 bar) with your burner and still maintain a good flame and not freeze up your tank (Where the vapor pressure would drop).

Propane approximate vapor pressure of liquid at various temperatures:
-20 deg. F ----10 PSIG
0 deg. F ------23.5 PSIG
+20 deg. F ----40.8 PSIG
+70 deg. F ---109 PSIG
+ 110 deg. F---197 PSIG

About 20 PSIG for the flashback on propane sounds correct (that is about what the capability of your burner would be) if designed and sized properly, The flashback is normally open until a back pressure (from a small explosion of pressure occurs), then the flash back closes quickly (much faster than a check valve can), the flashback is also much more sensitive than a check valve. It will still close under a greater pressure with no problem, but at below 20 PSI rating it will not close, so at 2 to 3 bar the flash back would still offer protection.

With your burner running greater than 1.5 Bar (if it could without problem), the flashback would still do its job, and would not slam shut, the burner would not build that pressure inside the burner to give back pressure to the flash-back arrestor.

Again here is where the design
of the torch differs from the burner, the torch would build back pressure enough to overcome the flash back spring setting and would shut off the fuel supply, until the pressure wash lowered, or the flashback event was over(explosion was out and the pressure in the torch dropped below the flashback setting.

If you wish to see the pressure you can always plumb in a gauge into your system with simple tee fitting...
Most of the time I see no reason, but it would be a nice feature while trying to design your burner or monitor its actions and reactions...

I hope this helps, again with your safety ,check what I say with other resources, I may not always be right in what I say.

I am not sure if you are abbreviating words, if so please spell them out, it becomes a big problem with translations or understanding of comments or questions. and it is hard enough for us to understand each other as it is.

With the long pipe and small air pipe the burner in your picture could act more like a torch, make the blower pipe bigger, I would also put the fuel orifice fitting closer to the burner tip. look closely at the picture I posted above.


good site lots of information on homemade burners and forges.
http://www.backyardmetalcasting.com/oliverburner1.html
http://www.backyardmetalcasting.com/index.html
http://www.backyardmetalcasting.com/blowburner01.html


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## saadat68

Thanks a lot
So I will buy 0-3 bar regulator and hop it works 
And also buy 3/4 or 2/3 inch black iron pipe for blower


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## saadat68

Fortunately it works 
I changed pipe too 
http://uupload.ir/files/470z_img_20170813_205821.jpg

-------------

I have a question for future 
I want to use natural gas lines instead of cylinder in next year. I tested flashback arrestor in my home with natural gas line and it doesn't work because gas pressure is very low. I don't need flashback arrestor in these lines. right ? 

http://uupload.ir/files/tdx6_img_3906.jpg

http://www.istgah.com/images/2017/04/21/1846772_k6z0FQ_r_m.jpg


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## butcher

The burner looks much better in design.

If I Understand you.
You said it is working now.

I would like to see a picture of its flame, to see if I can tell if the flame is oxidizing (good blue inner cone) or a sooty yellow flame. if you do get picture try it in dark light so picture shows flame good.

The burner, if it works well on propane will work just as well on natural gas, you will just need to change the fuel orifice size (hole at fuel tip).

I notice you have large traps on your gas lines (we use traps here also) but not that big or P trap shape (here we just make a small one with plumbing fittings a tee and a pipe nipple and cap to clean them out. your gas lines must be much more dirtier than ours or have more rust or water???

I am also wondering what the long white material the roof has is it insulation or some type of white brick?

I see no tee where the fuel line goes into your 1-1/2", 2" or 3" pipe, did you just drill and tap it for threads (or welded)?
Or is it put together yet? I cannot tell from the picture. make sure you have no leaks there.

The same thing with the flash-back arrestor, with natural gas as we discussed with propane, not needed for your burner, but a good safety feature to have.

Make sure to use good hoses rated for propane,or the gas you use the burner on, make good connections with no leaks. A leak in the hose next to you and your furnace (well you get the idea).
Some gases can make glue out of some types of hoses...

Give us some details of sizes of pipes, orifice size (hole in fuel port end) and so on. Posting details will help other forum members reading this, and wanting to build themselves a burner.

Looking forward to seeing your burners flame, good job, maybe we can get past (at least some) of this language barrier.


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## saadat68

Thank you butcher
My burner need some welding and a valve for working. I will add some images after completion 
I mean my flashback arrestor works. 

What is trap ? Do you mean gas meter ? 
https://en.wikipedia.org/wiki/Gas_meter

Gas in here is clean and I think it is butane or much of it is butane. We say to this gas lines , *city gas*.

Those white materials are :
https://www.google.com/search?biw=1093&bih=510&tbm=isch&sa=1&q=styrofoam+roof+panels&oq=styrofoam+roof+&gs_l=psy-ab.1.0.0l3j0i30k1.5745.5745.0.7058.1.1.0.0.0.0.207.207.2-1.1.0....0...1.1.64.psy-ab..0.1.207.bs3Fdhtgyd8

That house in image is not complete and I added it from google image 
I take a picture from my home :
http://uupload.ir/files/0bmc_img_20170814_124346.jpg

sizes of pipes:
Gas pipe is 1/2 inch
Blower pipe is 1 inch 

Orifice size: 
I don't know what is it's size. Here we have 2 model orifice . first model is for city gas and second is for cylinders gas. Orifice hole of city gas is bigger than cylinder gas. I bought one of them and add to my pipe with fitting
https://cdnimg.webstaurantstore.com/images/products/main/110664/192940/all-points-26-3947-burner-orifice-80-liquid-propane-13-32-27-thread.jpg

http://www.netwelding.com/Orifice%20in%20Fitting.jpg


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## butcher

Thanks for satisfying my curiosity.
The holes in the fittings are what I call an orifice natural gas is bigger than propane, we use drill sizes here, and I make my own for the burners I build, your gas is probably not much different than ours we may just use different names.
What I call a trap is the U shape in the pipe, used to trap dirt, rust. water...
If you can get the pipe cut and threaded you could use a 1"X 1/2 tee (1' both ends, 1/2" in middle) with teflon tape to seal threads.

The web site I posted has good information on the jet or orifice sizes, and regulator pressures...


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## saadat68

First I want to say I decide to remove flashback and high pressure regulator because there is very very high pressure in hose and always I see leak. This is dangerous and I prefer use low pressure regulator. 

In other websites that I checked there isn't any flashback on their hose for example :
http://www.backyardmetalcasting.com/blowburner01.html

-------------------------------------------------
Today I weld pipes and test burner. Something is wrong 
http://uupload.ir/files/04k_img_20170822_173610.jpg

When I used high pressure regulator (that I don't want use it again) I got these flames:
http://uupload.ir/files/uzcj_img_20170822_172340.jpg
http://uupload.ir/files/y548_img_20170822_172232_burst5.jpg

If I add more air the flame turns off. I couldn't get neutral and blue flame 
--------------------------------------------------
When I used low pressure regulator like this :
http://www.backyardmetalcasting.com/blowburner01.html

I got just a small and yellow flame like a big candle! Sometimes I got blue and yellow flame with air adjusting but it turns off rapidly 
What is the problem ? Maybe my pipe is too large ? (It is 1-1/4 Inch)


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## butcher

The yellow flame is what we call a reducing flame, as it can reduce the the more reactive metals to their elemental state. The flame lacks oxygen, your fan is not giving enough air for the amount of fuel you are using, either a bigger fan or using a smaller gas orifice will fix.
The flame Yellow is giving off un-burnt gases full of carbon 9which makes it a good reducer of the metal salt to metal elements, sometimes we want this type of flame but it really depends on what we are doing. (this flame can also introduce more pollutants into the air). Normally not what you want in your furnace, but their are times it is very useful.

The Blue flame can be a neutral flame. A very hot flame with just right on oxygen to fuel ratio, this will produce the best heat. We call the flame here stoichiometric combustion or chemical reaction exactly how much of both chemicals needed in the chemical reaction, or just the right amount of fuel with just the right amount of air for complete combustion, this will also be the cleanest flame and will produce the least amount of pollutants into the air...

We can also provide more air or oxygen than gas it will also be a blue flame but different at burner, and less heat. This is an oxidizing flame it will make salts of metals that oxidize more easily, make rust out of iron for example. 

See the reactivity series of metals, carbon is added to the chart as a reference, to which metals can be reduced with carbon.

High pressure regulators are normally where you have larger burners, most high pressure regulators can be adjusted down to a low pressure, many or most of the low pressure propane regulators can not be adjusted and have a fixed setting.

Fuels can attack hoses and become very dangerous, different fuels nee different types of hoses, be sure your hoses are rated for the fuel (and pressures your using them with). a fuel leak or busted hose is not something you want to happen, a leak can fuel an area with fuel making a dangerous situation to be in.

Using the improper hose for the fuel you are using is just an accident waiting to happen.

Looks like you are making good progress, adjustments or tweaking your design is all part of the game when you are building your homemade burner, learning what it needs and what makes it work is an important part of that process.

Sorry I was having trouble seeing the pictures you posted. But this is probably what you were talking about.


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## saadat68

Some usable information about flash back arrestors 
http://www.alloyavenue.com/vb/showthread.php?13336-Propane-burner-safty&p=205746
----------------------

https://image.ibb.co/c4ufWk/IMG_20170822_172340.jpg
https://image.ibb.co/hM65xQ/IMG_20170822_172232_BURST5.jpg
https://image.ibb.co/k48UP5/IMG_20170822_173610.jpg
-------------------
Thanks butcher
But I don't think a bigger blower will fix the problem. Why? 
Because I adjust air with valve and I opened just 30% of valve!
If I let more air go to the pipe, flame will turns off! 

I also want to know why burner don't work with low pressure regulator. In this page he works with BBQ regulator 
http://www.backyardmetalcasting.com/blowburner01.html

Maybe gas does not mix with air completely.
https://preview.ibb.co/eemSSQ/IMG_20170823_123711.jpg


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## Shark

Look closer at the picture Butcher posted here.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=8471#p275607

The cone on the end of the burner will help stop it from blowing out in many cases. Some of my earlier burners would not run outside of my furnace without that cone, but ran very good with one. It may not be your problem but it could help.


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## saadat68

Thanks Shark
I will make a cone I hope cone fixes my problem 

I see a video in youtube that his burner did not work. I think his problem was like my problem 
As my English is not good and he don't show fixing burner, can someone see this video and explain how he fixes burner and what he says about problem ? 

4:00 min to 4:50 min 
https://www.youtube.com/watch?v=l697pB9X5TI

He has another video that he makes a cone for his burner but I did not understand it relates to first video or not but I can see his burner works better with a cone 
https://www.youtube.com/watch?v=S6GcaKsRGDM


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## Shark

The first video he is using waste oil for fuel. I am not that up to date on waste oil use. 

In the second video his problem is when he adds more air the flame blows out, by adding a cone, it stays lit and should produce more heat when and where he wants it. I went through the same process when building my burners. The cone does not have to as complicated as his to work well. For one of mine, I simply added threads to the burner end and screwed on an coupling. When I added it to the furnace, I removed the coupling.


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## saadat68

> when he adds more air the flame blows out


I have same problem 
Hope solve it with a cone 

Thanks Shark


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## saadat68

It does not work even with a cone and inside the furnace!!! 
My gas pipe is 1-1/4 inch, I want to build a new one with 2 inch pipe. What do you think ?

http://uupload.ir/files/di4i_img_20170827_195229_ao_hdr.jpg


Video: (with low pressure regulator)
http://iranbm.com/saadat68.mp4


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## Palladium

Quit chasing your tail and just build one of these for a few dollars in an hour or two. If your using natural gas the only thing you need to change is the orifice hole size. You need a adjustable regulator so you can control the gas flow.


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## Palladium

I see the problem now. Unless you are going to bypass the residential gas regulator you can't boost your pressure to use the Reil design. That's why you are using a blower. I would just use LP and go with a Reil burner. Less trouble and no moving parts to go bad. Surely you have LP gas tanks in Iran?


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## butcher

I agree trying to get the right air fuel mix with the blower will be challenging, especially when building your first burner.


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## saadat68

Palladium said:


> I see the problem now. Unless you are going to bypass the residential gas regulator you can't boost your pressure to use the Reil design. That's why you are using a blower. I would just use LP and go with a Reil burner. Less trouble and no moving parts to go bad. Surely you have LP gas tanks in Iran?


Hi
Thanks
In my workshop I don't have residential gas. I have 2 LPG tank with 2 regulator. 
low pressure regulator gas output: 0.5 psi 
high pressure regulator gas output is : 4 - 44 psi

I test it with both regulators and with natural gas in my home

I prefer build a burner that works with blower (It is very better than venturi type) :? 



> "Atmospheric" a.k.a. "venturi" a.k.a "self-aspirated" burners are very popular because of the convenience of not needing an air blower and electricity source to power it. But they are also wasteful compared to blown air burners. The typical homemade atmospheric burner requires a high pressure regulator to blast propane through it at over 10 PSI, creating a low pressure zone or "vacuum" in the burner tube to suck in oxygen for combustion. With this high gas pressure far more propane is being blown in than can mix evenly with the air. So it get's wasted and doesn't burn until it exits the vent hole and contacts fresh oxygen creating a pillar of fire. *Next thing you know, the propane tank is "freezing up" and running empty after about 5 or 6 melts.
> *


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## butcher

Both will produce a good flame for a furnace, the venturi burners work well with smaller furnaces, the blower style is used in larger furnaces. I would not say one is better than the other, as it depends on the application or furnace the burners are used in, and how well the burners are made.
The trick is to get a proper mix of fuel to air ratio.
Getting the air to fuel ratio correct is the key to getting the burner working, with the blower it can be a bit more of a challenge than using the venturi burner.

A cone, burner diffuser head, or burner ceramic cone, can help to maintain the flame once the proper air fuel ratio is achieved.

http://waynecoeartistblacksmith.com/uploads/Ribbon_Forge_Burner.pdf
http://anvilfire.com/article.php?bodyName=/21centbs/forges/gasburn1.htm
http://www.metalartistforum.com/maf/index.php?/topic/6452-hans-peot-designed-lp-gas-tube-forge/
http://www.metalartistforum.com/maf/uploads/monthly_05_2011/post-1069-063665600%201305754755.jpg
https://www.iforgeiron.com/topic/46253-another-new-forge/







Note: the diffuse cone (burner head)
Note: propane orfice centered in air stream for better mixture of fuel and air.


----------



## Palladium

You seem to want to do things the hard way!
I'll leave you to your tinkering.


----------



## saadat68

Palladium said:


> You seem to want to do things the hard way!
> I'll leave you to your tinkering.


I just want to work with low pressure gas. In another forum one person said to me if you want to work with natural gas and low pressure gas you must make a burner with 2 inch pipe. Today I build it and tomorrow I will test it.
If it does not work I will build venturi type
Also I think finally I will work with a venturi type that you send it's plan


----------



## saadat68

My new 2 inch burner didn't work even with a 2 inch pipe and high pressure propane 

I will make a venturi type. I buy 3/4 inch pipe and 1 inch and 1-1/2 inch reducing bell today

Thank you 
Saadat


----------



## kjavanb123

Hi

Here is a very good video explaining how to build a venturie type burner.

https://youtu.be/eO8NwseRxSA

There is another video by the same person shows how to turn a trash can into larger furnace for larger cruicble.

Melted copper in 20 mintues.

Regards
Kj


----------



## 4metals

Excellent video and easy to follow instructions. No reason for anyone not to smelt now!!


----------



## FrugalRefiner

Depending on where you are, standard white Teflon tape may be illegal on gas lines. A heavier, yellow version is available for use on gas lines. Because it is thicker, it is not as prone to shredding as the thinner white tape. Many areas require the use of yellow tape on small gas lines. Of course, you will probably never be inspected, but there is a safety reason for using the right tape.

Dave


----------



## butcher

Never use oil on oxygen tank fittings, hose fittings or regulators, most pipe dopes contain oil and cannot be used on oxygen fitting, because of risks of fire or explosion, even the protective cover cap for the valve should never be oiled, keep the oil away from oxygen.

Acetylene with some of the metal salts can also pose explosive dangers, not the flame but the gas itself.

Anyone using a torch or a burner or furnace should study the safety of its use, like with most of what we do, the dangers lie heavily upon us, when we do not know the safe use and proper care of the equipment, a little study can not only help us to use it better, but can keep us from an accident from not knowing the danger are even there waiting.


----------



## kjavanb123

4metals said:


> Excellent video and easy to follow instructions. No reason for anyone not to smelt now!!



4metals,

Excellent is what you and other senior members of this great forum have been doing for all of us, with your in-depth yet simple posts about so many subjects.

I thank you and others for providing me with so much information all these years, that allowed me to build equipments based on your posts.

I reas your excellent post on smelting few times and in progress in putting together pieces yo mentioned in that post, and will post them under the same post as soon as they are complete.

Again thanks so much sir
Kj


----------



## saadat68

@Dave
Thanks. Here we have just white teflon

@kjavanb123
Thanks 

@butcher
Thanks. I know. You said me before 
Also I don't use oxygen tank or acetylene tank



> I thank you and others for providing me with so much information all these years, that allowed me to build equipments based on your posts.


I must say thank you too


----------



## saadat68

What is this flame ?
Is it oxidize flame or neutral ?

http://uupload.ir/files/zryl_img_20170831_194849.jpg

http://uupload.ir/files/08yg_img_20170831_195625.jpg


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## 4metals

My guess would be neutral, not yellow enough for a strong oxidizing flame.


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## Palladium

Where you have the nozzle welded to the screw in ring your blocking and disrupting the air flow. The gas won't mix efficiently.


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## Topher_osAUrus

Palladium said:


> Where you have the nozzle welded to the screw in ring your blocking and disrupting the air flow. The gas won't mix efficiently.



Wise words.

Dont know why, but it made me think if an old "as seen on tv" thing-a-ma-jig. -The vortex-, or tornado, maybe vornado?
Anyways, all it was, was a few fins with holes to help mix the air fuel ratio and "get better gas mileage" (how it mixed the air and fuel better, while ONLY being in the airbox line, i haven't a clue)

But, would something like this be applicable to his problem?


Having it in line, after the fuel injection point, so the fuel and air can get a more intimate mixture before ignition?

If not, sorry for the distraction.


----------



## saadat68

Palladium said:


> Where you have the nozzle welded to the screw in ring your blocking and disrupting the air flow. The gas won't mix efficiently.


Thank you all 
It sucks a lot of air and without closing pipe it doesn't work.
I closed my pipe with cloth just for testing. Tomorrow I will make something for closing pipe and adjusting air.
Hope it will get me completely blue flame. But I don't think it will get me a better flame because I tried many today to get blue flame and It seems has a problem 

Welding 2 inch pipe instead of ring can solve problem ? It helps gas and air mix in a bigger place 
http://uupload.ir/files/llaj_img_20170831_235520.jpg

@Topher
It can be obstacle on venturi effect ?!


----------



## Topher_osAUrus

saadat68 said:


> @Topher
> It can be obstacle on venturi effect ?!



I honestly do not know.

If you had it in line with a blower I don't think it would be an issue. With a venturi set up though, it may cause restriction and prevent ignition. I would imagine the location of it would either cause you grief, or success. However, this is nothing more than speculation.

Sorry I am of no assistance. I do eagerly read this thread though, as I am building a furnace now. -debating on a blower or venturi design. 

I very much like the simple design suggested by kevin, in that youtube video. ...actually, that youtube guy has a lot of interesting videos.


----------



## 4metals

To get a reducing flame you will be cutting air back and cutting fuel back. In your photo the gas is full open, that flow of gas requires a lot of air to burn all of that fuel to get to a reducing flame. Try limiting the air and cutting back the fuel. You will have to play with both air and gas to hit the sweet spot, you won't get there just cutting the air back. You will also hear it roar when it is right.


----------



## Shark

This is from when I was making mine. The second half of the video doesn't do the "roar" justice as I couldn't stand to get any closer with the camera. I had to use the zoom to get that footage due to the heat.

[youtube]http://www.youtube.com/watch?v=_8KERa2p0V4[/youtube]


While I use LP gas the smaller burner produces more heat, I think. I have no way to check the actual temperature but the smaller burner will melt copper fairly easy, while the larger one never did.


----------



## Palladium

Cheap, but effective for what we do. And when your not melting it can be used to drive the cats crazy! :lol:

http://www.ebay.com/itm/Digital-LCD-Temperature-Gun-Non-Contact-Digital-Laser-Infrared-IR-Thermometer-/130979214461?epid=691193511&hash=item1e7ef8347d:g:dcMAAOSw2xRYXKWc


----------



## Palladium

Do NOT use a 2in pipe unless you plan on turning the pressure wayyy up as well as the volume and changing the orifice size. The hole size is designed on the mixing chamber size (3/4 in). You can't just change one thing without changing another or you will be chasing your tail again! Like 3metals pointed out you will have to adjust your pressure as well as increase or restrict your air flow to hit that sweet spot. I bought mine premade off ebay because i didn't have time to mess with it, but mine will rock and roll even in that big furnace i built on the farm. Follow the design i posted one page 1 of this thread and don't change anything. I love the roar of my furnace and can tell halfway across my property just by listening to the roar if it is running right or not.


----------



## Shark

Palladium said:


> Cheap, but effective for what we do. And when your not melting it can be used to drive the cats crazy! :lol:
> 
> http://www.ebay.com/itm/Digital-LCD-Temperature-Gun-Non-Contact-Digital-Laser-Infrared-IR-Thermometer-/130979214461?epid=691193511&hash=item1e7ef8347d:g:dcMAAOSw2xRYXKWc



Mine only reads to 700F, it won't even come close to reading the inside temperature. After running the furnace for 1 hour it will read the outside as 160F average with the highest being 180F.


----------



## Palladium

Hummmm..... I thought somewhere there was a question about the furnace body temp. I had three windows open at once and i guess i confused the question from another thread with this one. lol


----------



## saadat68

4metals I cutting back gas with tank. I try again today with adjusting air and gas 

Palladium I just use a 1/2 inch pipe instead of 1/8 inch for orifice because I can not find 1/8 inch pipe here also my pipe is out of chamber and orifice is very smaller. you can see in my image
I really built it from your plan and videos from YouTube 

I think my problem can solve with 2 inch pipe because :
1- in many images I see their burner have this pipe and the orifice adds to this pipe (look to Shark's new burner )
2- You said copythat plan and I say OK, So I will add 2 inch pipe. Look this image:
http://uupload.ir/files/xn86_untitled_-_2.jpg
This is my mistake. Right ?

Edit:
Burner in Kevin's video is like my burner so I don't think 2 inch pipe solve the problem 
http://uupload.ir/files/zucl_sdfg.jpg


> Where you have the nozzle welded to the screw in ring your blocking and disrupting the air flow. The gas won't mix efficiently.


If I add nozzle like upper image can solve the problem ? (My weld is smaller than these screws)


----------



## saadat68

I cut pipe of air force burner today for something
Then I decide to test my air force burner again. *I think* it works  
It doesn't blow out when I add more air. If I add more air, I will get a red and strong flame 

Video from flame that I think it is neutral:
Color is 95 percent blue and have a good roar 

http://iranbm.com/saadat68.mp4


----------



## Palladium

I think the sound you are hearing is not the roar of the flame from a well tuned burner, but the sound of the gas as it combustes inside the burner tube. The flame needs to combust just outside the tube. You need more air to push the flame out of the tube and just past the end of the pipe. For the air ration of propane to burn right i think it is 23 parts air to 1 part propane. Now you see the importance of mixing properly!


----------



## saadat68

My pipe was red!!! You are very professional
I try again tomorrow
Is this flame neutral ?

I tried many today to get blue flame with propane burner but I couldn't even with this burner that I bought from shop 
http://uupload.ir/files/pz9w_img_20170901_193016_1.jpg

I said I cut the pipe of air force burner. now the orifice is middle of pipe and this section was red. If I add orifice near the blower can solve the problem ?
http://uupload.ir/files/bo7i_img_20170827_195229_ao_hdr.jpg


----------



## Palladium

Two questions. On the tube with the fan you said orifice. Do you mean you have a orifice with a hole drilled a certain size?
# 2 What kind of regulator do you have on the lp tank for the gas regulation? Is it the kind you use on cutting torches or a bbq grill regulator? If it is adjustable what is the highest pressure it will push out?


----------



## Palladium

I see now! Let me do some reading through this thread and run some numbers.


----------



## Palladium

Can you post some picture of your furnace? What is the load chamber size or inside furnace dimensions? 
What size crucible and how much are you trying to melt in one pour? 

There's to many variables in your design. As each parameter changes so does another one down the line. 
Let's get down and dirty!

Here's how i would do it. First use a 1 in pipe. Length doesn't matter. The longer the pipe the more mixing it has this way. Do away with the orifice. I don't think your getting enough gas from what i'm seeing. That's why you can only turn the air up so far before a flame out! The regulator and hose will deliver it, but your restriction is the orifice size. When i use to run and build aluminum sweat furnaces i have actually just drilled a hole in the side of the blower casing and put in a hose barb and piped the gas straight into the furnace. That was a trauma fix to keep from shutting down. It took $ 3,800 and 36 hours to bring that furnace up to operating temperature from a cold start not to mention you don't just shut a machine like that down cold turkey. You have to have a controlled temp drop or your refractory will sprawl all to hell and that's a $100,00 problem. 

After you do away with the orifice it gets pretty simple. All you need to come out the end of that pipe is pretty simple. Air+gas (mixed) = flame. With the air at 1/4 turn open to produce a light draft from the blower to keep the gas from back building into the fan, turn the gas a couple of psi and light the end. Turn the air up until you get a blue flame and the base of the flame leaps about a 1/4 from the end of the pipe. The color of the flame will tell you the sweet spot. If you add to much air the flame will change colors and when you add way to much air per gas volume it will flame out. Back off the air without turning the gas down and light it again. Then boost the gas a psi or so and the color will change to rich again. Then turn the air up until you reach the sweet spot at neutral again. Keep doing this in steps and the btu output will increase with each step. Once you get it dialed in you can record the psi of the gas and the turns of the valve you have to open for the air. Next time just set it and light it! It will take some learning and experience on your part, but it can't get much simpler than that.

Here's a good link http://www.comtherm.co.uk/tech-com.htm


----------



## saadat68

Thank you
I forget take image from furnace but I uploaded an image before http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=50&t=25677&p=273316#p273316
I think my crucible is #8 and I want to melt 500 to 1000 gram silver in one pour 
I have adjustable high pressure regulator with gas output : 0-43 psi 
It doesn't have degree bit I think I set it on 10 to 20 psi 
-------------------
I afraid remove orifice because I think it is unsafe. isn't it ? :shock: ( For example flame go back to the tank )
Here we have 2 models orifice. one model is for LPG gas and another is for natural gas. I bought LPG orifice but it was small than 1 mm. this was my mistake. (I didn't know #60 is 1 mm)
So I changed orifice with natural gas orifice that it is 1 mm. I get a better and stronger flame now.

-----------------
I tested this orifice with all of my burners. These are the best flames that I got

1-1/4 inch - air force burner :
http://uupload.ir/files/2hef_img_20170902_215536.jpg

Video :
http://iranbm.com/saadat68.mp4
Is this neutral ? If yes I can go build a new one with 1 inch pipe  
----------------------------
Venturi propane burner: 
http://uupload.ir/files/76z7_img_20170902_210351.jpg
------------------------
Burner bought from shop (I change it's orifice too ):
Can I melt with this burner? 
http://img31.114pifa.com/3315/7eAn5hrCV_1417975693.jpg

Is this neutral ?
http://uupload.ir/files/fomr_img_20170901_193025.jpg


----------



## Lightspeed

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=40&t=25610

research this site, there are plenty of links: http://www.hybridburners.com/index.html

I use one of these, Cheap on ebay: http://stores.ebay.com.au/Thermal-Art-Design?_trksid=p2047675.l2563

homepage: http://www.thermalartdesign.com/
Don't underestimate this burner it may be small but it is excellent, with the correct size chamber and refractory it will achieve what you want for your purpose

When you have done enough research you can draw your own conclusions, there are many functional ways to achieve what you want to. There is plenty of rubbish on youtube and a few that are actually good.

A few pics of mine just after the ceramic layer was applied to the ceramic fibre.










Play safe Saadat68


----------



## saadat68

Thanks Lightspeed
I made furnace before just need a burner 

Today I test air force burner with 3/4 inch pipe 
http://uupload.ir/files/hwvs_img_20170903_182338.jpg

I uploaded 4 images from 4 burner. Which one is neutral ?
I think the last one is the best. Right ?
Just it's flame is small.

------------------
*If I make an orifice with 3 mm hole and add to my burner, Is it safe? 
Is there a chance to flame back to the tank for example when bower turns off? * :shock:


----------



## saadat68

http://uupload.ir/files/hwvs_img_20170903_182338.jpg

My flame is like :
http://cdn.smokingmeatforums.com/1/10/667x500px-10dc2330_furnace_burner2.JPG
http://gaijinto.blogspot.com/2011/02/propane-burners-old-and-new.html

So it works and it is neutral. right?
If yes, maybe a one inch burner with 3 mm orifice will be better


----------



## Lightspeed

This first link is the the directive I have used to help me with setting my flame on my burner. However I do not use a used a forced air burner, I would imagine that due to the available oxygen from the blower it may be somewhat more of a challenge to get away from an oxidising flame, ideally you need adjustable air output on the blower, and a venturi on the burner to adjust at least some of the available oxygen mixing with the LPG/Propane, without this I don't see how you can manipulate or cause any effect on the Burners flame, other than by gas pressure adjustment at the regulator relative to air pressure.

Flame Settings: http://northstarglass.com/users-manual/flame-settings/

http://ronreil.abana.org/richtolean.jpg

http://www.hybridburners.com/new-vertouri.html

https://www.youtube.com/watch?v=75gJV3pcbME

A 3mm orifice, Wow you are going to consume a propane bottle in no time with that, its huge!! You will probably suffer from freezing issues with that amount of gas flow through the valves and regulator.
Study the above links, you must read what is contained and study your burners flame, the flame you have shown looks like its oxidising to me, due to the amount of fuel from the orifice it may not be.


----------



## saadat68

Thanks Lightspeed
If I use 3 mm orifice I will use a low pressure regulator too to prevent freezing tank 



Palladium said:


> Here's how i would do it. First use a 1 in pipe. Length doesn't matter. The longer the pipe the more mixing it has this way. Do away with the orifice. I don't think your getting enough gas from what i'm seeing. That's why you can only turn the air up so far before a flame out! The regulator and hose will deliver it, but your restriction is the orifice size. When i use to run and build aluminum sweat furnaces i have actually just drilled a hole in the side of the blower casing and put in a hose barb and piped the gas straight into the furnace. That was a trauma fix to keep from shutting down. It took $ 3,800 and 36 hours to bring that furnace up to operating temperature from a cold start not to mention you don't just shut a machine like that down cold turkey. You have to have a controlled temp drop or your refractory will sprawl all to hell and that's a $100,00 problem.
> 
> After you do away with the orifice it gets pretty simple.


Hi
I want to test again without orifice. Is it safe ?
Is there a chance to flame back to the tank for example when bower turns off?
Is 3 or 2 mm orifice better and safer? (Because I can not find 1/8 or 1/4 inch pipe)
Thanks


----------



## Lightspeed

I think you should get away from the blown burner for a first burner project, this thread seems to be going in circles, the info already posted is tried, tested and accurate, the web links and pics from Butcher and info from Palladium are also accurate. A blown burner is not necessary for your melt size, eg: look at the burner flame on the T/rex for proof if you scrap the blower and simply run a venturi burner with what you have already experimented with you would have found success. You do not even need more than 1 1/4 inch, 1 inch is more than adequate. You are trying to build a Saturn 5 Rocket and its simply not going to be economical to run for small melts, my 3/4 venturi burner easily melts 1kg charges at 20psi, I can wind it up to 160,000 BTU but I simply don't need to.

Make things easy on yourself and put a gas needle valve, or gas ball valve inline with the fuel feed so you can play with varying amounts of fuel mix and air, not just a straight feed from a regulator.

Your Burner tube needs a bell on the end at the least or a flare of some description.

I do not have experience running open pipe for a fuel orifice, sounds like Palladium has, though, I cannot advise on its use from a safety aspect, myself, my own mind tells me to be wary. As already stated an arrestor is not needed unless you are mixing an oxidiser and a fuel source combined, don't take that as a go ahead and try it from me though. That being said your fuel should not burn unless oxygen is available, beware, a danger exists when running at low air pressure, where the combustion will take place inside the burner tube or at the orifice itself.

There has been so much info already linked and posted from people speaking from experience, the sources of which are tried and tested proving functionality. You have already posted pics of burners of which the flames just needed some tweaking from either increasing fuel available or reducing oxygen input.
I don't want to tell you to stop building but you should, you are nearly there and have the persistence, you just need the knowledge......research.

If you change anything, change 1 thing only at a time and test all parameters available, eg air input volume, gas/fuel input volume and observe, from that deduce your hypothesis make 1 single change, re test and observe.


----------



## saadat68

I made a propane burner before. The nozzle block air flow in my burner because I can not find 1/8 inch pipe so I used 1/2 inch and it blocks the air 
http://uupload.ir/files/xod8_img_20170902_210351.jpg

Do you know what is this flame ? I think it is reducing flame


----------



## Lightspeed

Saadat68, is that with the blower running?

If you are using a blower the reality is if properly set up you should be using less fuel for the same temperature than a venturi burner. What does that mean? It simply means if you are using a blower that is ramming an excessive amount of air for your needs, you in turn need to provide it more fuel to keep the thing lit.

That flame is looking close to right, but it is excessive for your furnace. Play with the air input first and see the effect it has, observe and record changes/settings with phone camera for reference, you will see the flame change characteristics. 

Less air pressure: the flame will go more yellow and softer in appearance as the mixture is more rich with fuel also losing some of the audible roar.

Reducing flame; More Fuel/same air pressure: Will produce similar effects to Less air pressure, by making the mixture more rich, flame colour will become more yellow and softer in appearance with smoother tips around the end of the flame, the flame will become quieter audibly.

Oxidising Flame; Less Fuel/same air pressure: Will produce a more Blue flame, the flame tip will display sharper flickering tips around it and also become more audibly noisy/roar. 

After playing with air pressure, while keeping the pressure lower, try lowering the fuel output and observe and record with phone camera. By doing this you will easily see the flame types and find an workable flame setting range for the burner giving ease of adjustment

Flame types are actually simple, I have already posted a link on how to tell them apart along with the specific indicators of each type. You need to assess the individual characteristics of the burner you have made, and adjust accordingly from your baseline testing. Patience and observation is required. 1 change at a time ONLY.

Do you have a lid for your furnace? you are going to need it or you are going to lose all your heat. In amongst the links I posted there is information on exhaust size and is directly relative to Burner size. 

I hope you can wind that thing down so you can heat your refractory and crucible to operating temperature slowly without destroying them by sticking a rocket engine in front of them while they are cold.


----------



## Palladium

You don't need an orifice. Propane will not burn back into the tank. Fire is a chemical reaction. It requires an accelerate and an oxidizer. It has a propagation rate. That's the rate at which the chemical reaction occurs according to the available oxidizer. Think of it as a beaker of hcl with gold in it. Just hcl and nothing happens. Now add an oxidizer like cl or nitric and the reaction proceeds. Remember i told you you needed like 23 to 1 or 25 parts air to 1 part gas for it to burn? The line as well as the tank has a saturated solution of gas with no air to carry the chemical reaction forward, so their will be no fire to run back into the tank. He's right about the burner. The Reil burner i posted a diagram for will push an average of 150,000 btu's which is all you will need for that small furnace. The larger the diameter of the pipe for the burner the more btu's you have to push to get a balanced flame, hence a Saturn 5 rocket! 1 inch is all you need. I built a furnace with a large chamber for one of my first builds way back and the 1 inch was more than adequate.


----------



## Palladium

If you used two of these like the one you bought it should work. If it doesn't put out enough heat fast enough then take a small drill bit and increase the orifice size of each burner a little at a time until you reach the desired result.


----------



## saadat68

Thanks 

Lightspeed
No It is reil burner 

Because I had 2 inch pipe I made this design and without any orifice 
http://anvilfire.com/21centbs/forges/gasburn1.jpg

Didn't work !!!
OK I will find a solution 
Maybe one inch works 
I will go for find a 1/8 pipe for reil burner too.


----------



## saadat68

Palladium said:


> If you used two of these like the one you bought it should work. If it doesn't put out enough heat fast enough then take a small drill bit and increase the orifice size of each burner a little at a time until you reach the desired result.


Sorry palladium 
Do you see my video ?
It is for 2 days ago with 1 mm orifice and 1-1/4 inch pipe 
http://iranbm.com/saadat68.mp4

It's flame is like shop burner but stronger. Can I use it ? Maybe with one inch pipe and redesign it I will get better flame too


----------



## Palladium

No need to change anything. Take it out of that other blower and pipe, put the head back on it like it came in the picture i posted above. Remove the orifice that came with it and drill the orifice a little bigger to let more gas through. Reassemble and test. Before you drill the orifice try boosting the pressure. Twice the pressure equals twice the gas without drilling the orifice.


----------



## autumnwillow

Palladium said:


> I built a furnace with a large chamber for one of my first builds way back and the 1 inch was more than adequate.


Would you mind sharing the size of that furnace?

I'm currently building one so I'm not sure with the sizes of the burner pipe yet.


----------



## butcher

Been too busy to follow the thread, just watched the video and seen that burner is roaring.
It would work in a larger furnace.

I like seeing the progress you have been making and especially see you learning so much in your goal of making fire and your burner.


Fire is a simple chemical reaction, heat, fuel and air, we just need to get the right reaction going and feed it what it wants, lately I have been busy trying to remove the fuel to keep the fire from burning. while you have been trying to get the fuel to burn with the right amount of air.

I am kind of lost where your at with your furnace or burner, but I enjoy seeing the progress.


----------



## Palladium

autumnwillow said:


> Palladium said:
> 
> 
> 
> I built a furnace with a large chamber for one of my first builds way back and the 1 inch was more than adequate.
> 
> 
> 
> Would you mind sharing the size of that furnace?
> 
> I'm currently building one so I'm not sure with the sizes of the burner pipe yet.
Click to expand...


https://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=20874&p=215733&hilit=furnace#p215710


----------



## autumnwillow

Ahhh I see. Very nice work. The burner pipe size was relative to the exhaust size. 

Correct me if I am wrong. After 3 years of usage from this type of casted furnace it is no longer usable due to cracks? 


Sent from my SM-G920F using Tapatalk


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## Palladium

Nope! Still just as good today! I've moved on to a different furnace setup. That one was for fun, but i like to push things to the limit to see how they will hold up to my design and to find flaws. For my first one it surprised me. I ran it just like you see with the wood and all. It melted several hundred lbs of silver and would keep melting today if i fired it up. The secret is in the refractory and the way you cast and dry it. I built it with cracks. The main chamber is 6 pieces. The top, bottom, and then the chamber is broken into 4 equal sections. It can be dissembled and moved then reassembled like a jig saw puzzle. It really starts to rock and roll after about 1 hr. Once the thermal mass of the furnace stores energy it literally melts faster than you can feed it! I'll try and get some measurements tomorrow. I think the burner is 1 inch and the exhaust is maybe 2 - 2 1/4. I can't remember right now. If you make the hole to big you can regulate it by putting a fire brick on top and pushing it over the hole to adjust flow.


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## autumnwillow

What do you mean by you built it with cracks?
Are there existing cracks in the build that you just let it be? Is it causing problems? Heat leaking out perhaps?

When I was doing my research about DIY furnaces, most of the DIY guys used garden supplies and a common cement to create a refractory mix. Upon reading more, this was not good as cracks would often develop in a very short usage cycle.
So then, I found out about actual refractory cement that will last longer, so I tried to look for companies selling such and when I finally inquired I was advised to used bricks with mortar instead of a refractory cement.
Again, I did my research and it ends up that refractory bricks combined with refractory mortar are the best of all the three options that I have stated. As refractory bricks were properly heat treated in order to achieve such durability.

Although you could actually make a properly heat treated furnace with refractory cement that will match near the durability of a refractory brick. It is actually the spacing in between those bricks and mortar that make the furnace a lot more resistant to cracks.


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## Topher_osAUrus

autumnwillow said:


> What do you mean by you built it with cracks?
> Are there existing cracks in the build that you just let it be? Is it causing problems? Heat leaking out perhaps?
> .



Similar to how bridges and concrete sidewalks are built with cracks to take into account the expansion coefficient, so when heating it has room for the growth of the material.


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## saadat68

butcher
That burner didn't work because the combustion is in the pipe 


Palladium said:


> No need to change anything. Take it out of that other blower and pipe, put the head back on it like it came in the picture i posted above. Remove the orifice that came with it and drill the orifice a little bigger to let more gas through. Reassemble and test. Before you drill the orifice try boosting the pressure. Twice the pressure equals twice the gas without drilling the orifice.



Combustion is in the pipe 

I made a reil burner. It is like conventional design, Just my pipe is a little smaller. It is 8 mm with 5 mm hole.
I think 1/8 inch pipe is 10.3 mm
http://uupload.ir/files/5xdf_img_20170913_193431.jpg

And this is my flame. It doesn't work, Right ?
What is problem ? 8 mm pipe ? I am really hopeless
Can I melt silver with this flame ? Maybe in future I will make a good burner 

http://uupload.ir/files/uvbs_112.jpg
http://uupload.ir/files/5t26_113.jpg
http://uupload.ir/files/xiqx_114.jpg


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## Lightspeed

> And this is my flame. It doesn't work, Right ?
> What is problem ? 8 mm pipe ? I am really hopeless
> Can I melt silver with this flame ? Maybe in future I will make a good burner




Well it looks like it works to me, I do not understand why you are doubting yourself so much, is it just that you have not built and used a burner and furnace before?

There is no problem, the 8mm pipe with 5mm internal diameter it's fine and does obviously not inhibit the flame or its performance, where you have the fuel orifice you could countersink the orifice to a depth of 1/2mm, using a larger drill than you have used to drill the orifice itself just to help with fuel/air mixing. I can see your bit of cardboard at the air intake you are using to adjust the flame, a simple flat disc of sheet metal(even coffee tin lid) with a screw attaching it to the burner on one side is a simple permanent choke, allowing rotation for more and less air. 

And NO you are NOT hopeless.

Yes you can melt silver with the burner, it simply needs to be used in conjunction with your furnace.

A Burners performance also requires the furnace chamber and exhaust to be in reasonably correct proportion also. Your castable refractory will soak up a lot of heat before it starts refracting and not absorbing, as Palladium gave an example of with his aforementioned build.

I can't give advice on warm up of a castable refractory as I do not use one, but logic prevails. As the refractory is heated the moisture inside will expand, so go gently with the flame for a bit until the moisture has been driven off, similar to what you would do with a melt dish or crucible, just on a larger scale as your refractory lining is much thicker. If you go too quick the refractory will separate in places and large chunks may pop off and severe cracking will occur.

I think its about time you just tried it, and see if there's anything else along the way that may need ironing out. 

Preheat the refractory, then the crucible, then try a small charge only when you have confidence in what you are doing, map out your moves, practice a dry run on how you will handle the furnace lid when hot, removal of the crucible and its handling procedure while holding a molten charge before your pour. Use precaution and think ahead of any possibility that could cause personal danger and make a contingency plan for it or adjust your procedure accordingly. There are no second chances with 1200c molten metal.

Looking forward to seeing and hearing your progress. Play safe.


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## Shark

> http://uupload.ir/files/uvbs_112.jpg
> http://uupload.ir/files/5t26_113.jpg
> http://uupload.ir/files/xiqx_114.jpg



All three of these look good.


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## saadat68

Good advice about working with furnace in first time 
Thank you Lightspeed and Shark 
I made my furnace before and I think the burner is the last thing that I must build 
I can not drill hole because next number drill here is 1.5 mm and we don't have #59 or 1.2 mm drill here
But no problem if you say flame is good and neutral so I start melting and in next year I will make a better burner 
Good advice about working with furnace in first time 

Thanks all


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## kjavanb123

All,

I followed the Grant's youtube video I have posted here and made a propane burner.

Amazingly, I was able to melt 58 grams of copper in 10 minutes, here is some photos for your reference.

I highly recommend his YT video for anyone interested in bulding a furnace that can be taken anywhere since it does not need a blower.

My next plan is to build an afterburner based on design by 4metals in his infamous smelting thread.

Here is the oxidizing flame on the burner,



Feed material,



Molten copper in exactly 10 minutes after burner and furnace is lite. 



I just poured it on a piece of wood, but as it cools fast some beads also formed,




Thanks
Kj


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## Slaughlin79

I know this is an old post but I’m very familiar with. I’ve been welding/fitting/fabricating since I was 16 and I’m now 38 and I’ve got a lot of experience with a lot of different things.

It’s normal for us to have our acetylene gauges maxed out way passed the the red line. We use regular victor cutting tips to wash welds and having your acetylene along with oxygen pressures high makes the job go much quicker. Now we have never had a problem and I’ve never heard of acetylene exploding a little above 15psi. If that was the case then wouldn’t it explode in the bottle? Or do you mean high pressures of oxygen mixed with acetylene will explode? If so so than oxygen with any oil will explode if pressures gets high enough. That’s why when maybe some of you know as me when in a refinery there are some units that need to be wiped down with simple green or other non flammable degreaser and while wearing gloves bc the oils from your hands or body for that matter is all it takes. Conditions have to be pretty perfect though.

Now to the flashback. I’ve seen a hose flashback all the way to the regulator on an acetylene tank. Torch popped and heard the whistling and the hose exploded at the torch and every 6 feet of so It would have an explosion until it got to the cylinder where it just threw a flame out directly on the oxygen tank. You couldn’t have positioned the flame. It engulfed the oxygen and we all ran and called the fire department. 20 minutes that flame poured out engulfing that 1/4 full oxygen bottle. The firemen pull up the guy walks over to the bottle not a care in the world and just turned the acetylene bottle off and that was it. He said there was really no danger of the bottle exploding that it would have to get hot enough to compromise the steel and acetylene straight from a tank with no air induction can’t get hit enough. 

Anyways if acetylene exploded right above 15 or so psi then I can’t imagine gauges would legally be able to go near that and for sure way over. I’m not saying your wrong just debating from my own experiences.


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## butcher

https://www.google.com/search?source=hp&ei=uuGrWpnkIILijwPY1rDoDA&q=acetylene+pressure+should+never+exceed&oq=acetylene+pressure+&gs_l=psy-ab.1.4.0l6j0i22i30k1l4.2786.18698.0.20956.20.14.0.5.5.0.264.1542.1j6j2.9.0....0...1c.1.64.psy-ab..6.14.1604.0..0i131k1.0.cbgtzyHuspI


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## autumnwillow

It is not safe to use above 15 psi due to the possibility of dragging acetone which will not explode but ignite. If I remember correctly it corresponds with the amount of time that you are using it. I forgot already since I stopped using acetylene for melting.


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## butcher

Pure or less than pure acetylene above 15PSI (even without oxygen can explode (decompose violently).
Basically, explode into soot and water.
The acetylene does not need oxygen to explode, it can just from pressure or with some other unstable condition.

The red line on the gauge is there for safety reasons, OSHA rules on pressure setting and 15-pound max on the gauge for your safety.

The acetylene molecule is composed of two carbon atoms and two hydrogen atoms. The two carbon atoms are held together by what is known as a triple carbon bond. This bond is useful in that it stores substantial energy that can be released as heat during combustion. However, the triple carbon bond is unstable, making acetylene gas very sensitive to conditions such as excess pressure, excess temperature, static electricity, or mechanical shock. 

The tank has a porous mass to prevent voids where gaseous acetylene could collect, the acetylene is dissolved in acetone, which normally stays in the tank when tanks are handled, stored, and used properly. the acetylene dissolved in acetone is stable in the tank, also the porous rock-like mass keeps isolated, slows down and or stop decomposition inside the tank.

https://www.google.com/search?ei=vIKsWpuuD8W6jwPNra2ABA&q=acetylene+decomposition+pressure+&oq=acetylene+decomposition+pressure+&gs_l=psy-ab.12..0i30k1.15400.27932.0.30606.15.15.0.0.0.0.328.2198.1j13j0j1.15.0....0...1c.1.64.psy-ab..0.15.2190...0j0i67k1j0i22i30k1j0i13k1j0i7i30k1j0i8i7i30k1j0i13i30k1.0.lectDYPnO4w


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