# Torches



## CarlClassen (May 17, 2008)

Ok noob question time.

So I’m trying to inquart my scrap gold. I first tried to heat up the crucible like in lazerSteve’s video. But I quickly realized that the small jewelry butane torch aint going to get thing hot enough.

I know nothing about torches. What do I need to get? Is one of those hand held plumbing torches good enough?


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## SapunovDmitry (May 17, 2008)

Steve has a great melting video but it will be complicated to use an acetylene torch from the begining.
My scientific adviser once told me "Feel the flame first."(Sounds like Feel the force :lol: )
The first thing i tried myself was a butane torch.It made an ore from the powder. Then i tried propane/butane.It works much better.At least it is possible to melt. But acetylene has really good temperature in the gas flow and i usually use acetylene/oxygen torch (In the country house of course).
If you are not familiar with torches start with propane/butane torch. Because it will be dangerous for you to mix oxygen with other burning gases. 
Try something like Rothenberger burner with piezo ignition using propane/butane or butane. That's what i tried first.It costed me about 50 bucks to buy it. I think it's the most simple way.

I like bricks most of all. Once you've heated it enough it will hold temperature much longer than the dish. But of cource dish is more comfortable so it's up to you to decide.


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## CarlClassen (May 17, 2008)

SapunovDmitry said:


> If you are not familiar with torches start with propane/butane torch. Because it will be dangerous for you to mix oxygen with other burning gases.
> Try something like Rothenberger burner with piezo ignition using propane/butane or butane. That's what i tried first.It costed me about 50 bucks to buy it. I think it's the most simple way.



Awesome thank you for the advice. I'll see if I can find that torch. Most of them here seem to be either butane, or propane, or Oxygen/Acetylene

Is Oxygen/Acetylene that hard to use? Will I just want to upgrade to that later?


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## SapunovDmitry (May 18, 2008)

Well, actually it's not so hard. I have no doubt that you will likely upgrade to acetylene/oxygen in some time cause it's much better. But you have to buy oxygen cylinder, acetylene cylidner, two reductors for pressure control and a burner.You have to connect it properly. It's kind of labour intensive and spooky for a person who never made it before. It's much easier to go to the Obi or other supermarket and buy a single lamp and only one small propane/butane gas balloon  there.
It's up to you to decide though.


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## Oz (May 18, 2008)

If you are sure you are going to want to upgrade later get the larger oxy/Acetylene tanks instead of the 1 foot tall mini tanks. The small tanks cost almost the same to fill as the large ones and last 10 times longer. Then you can do welding and cutting as well w/o running out of gas all the time. The bigger tanks are a bit more expensive but you will save enough after 1 filling to recover the expense by not having the 10 trips and 10 refill charges.


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## SapunovDmitry (May 18, 2008)

Yeah. Oz is right about it. They are much better.


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## Anonymous (May 18, 2008)

Use and air/acetelene thats what I use for refrigeration repairs. I do not know the temp it runs at but I can melt copper very easily.


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## Platdigger (May 18, 2008)

"Use and air/acetelene" hmm, never heard of this. I have oxygen/acetylene.

Where would a guy look for this type of torch?
Randy


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## markqf1 (May 18, 2008)

Carl,
Here in the states you can rent the large tanks from the companies that sell the gases. Of course if you rent them, then only the company that you rented them from will fill them for you. It's a much cheaper way to get started than forking over alot of cash(they are very expensive) for them.

Mark


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## Anonymous (May 18, 2008)

Refrigeration supply companys, johnstone supply, graingers. 
If you go to a local refrigeration place they can also get you on a bottle
exchange program that is pretty cheap. I use the smallest bottle, I think it is size A, because I have to carrying everthing up on roof tops and into
ceilings etc.

The torch will have 1 knob to turn the gas on and it has breather holes at the base under a guard, other than that it looks exactly the same as a
brazing/welding torch.


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## Rag and Bone (May 18, 2008)

The small oxygen tanks make it really expensive to melt gold. I found a guy at a bike shop who lets me use his torch. I give him some money for gas and everybodys happy. I'm sure you could find someone in the neighborhood who would let you use their torch. Once you tell them what it's for their eyes will light up and they will be very interested.


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## Oz (May 18, 2008)

James,

Are you sure that is acetylene your burning? When I light my torch on acetylene only, it burns very dirty with carbon floating in the air until I kick in the oxy to get a clean burning flame. Some people even soot their molds with straight acetylene so the gold doesn’t stick when poured. If you were using compressed air with acetylene it might work, but it sounds like you are talking about a torch that operates like a plumbers propane soldering torch.


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## CarlClassen (May 19, 2008)

Ok well I couldn't get a normal plumbers propane torch to work either. The ace-oxy torch is $300 and the propane one was $20. The problem is that whenever I go to heat up the crucible the flame goes from a blue flame to a red flame and then the torch goes out. It doesn't seem to like being held at the 90 degrees angle I need to heat the crucible on the ground.


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## CarlClassen (May 19, 2008)

Oz said:


> If you are sure you are going to want to upgrade later get the larger oxy/Acetylene tanks instead of the 1 foot tall mini tanks. The small tanks cost almost the same to fill as the large ones and last 10 times longer. Then you can do welding and cutting as well w/o running out of gas all the time. The bigger tanks are a bit more expensive but you will save enough after 1 filling to recover the expense by not having the 10 trips and 10 refill charges.



Thanks for the Tip Oz. That will definitely save me some $ later since I would have gotten the smaller ones.


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## ALPHABiT (May 19, 2008)

Isnt a clearer way to use PROPANE + OXY ? 
I use it.
SO u can start with propane only to "get confidence" to upgrade to oxy too l8er...


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## Platdigger (May 19, 2008)

So do I Alpha, I was a bit curious tho, about this actylene/air torch, (if there was such a thing). As that would be even cheaper to run.
Randy


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## ALPHABiT (May 19, 2008)

Dunno there... But acetylene is more expansive then propane here in Italy... And sounds a more "dirty" flame then pure propane...
Acetylene i see is use to cut pipes and so on... All gold masters i know use propane here. With Oxy or simply with air ("mouth using" in a plastic pipe!) to liquify little gold parts or to sold.


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## Kurr (May 20, 2008)

Ive seen propane and compressed air used. 

http://www.britishblades.com/forums/showthread.php?t=11056&page=2

shows a nice setup.


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## CarlClassen (May 23, 2008)

After much thinking i decided to splurge and buy an oxy/act torch. My next question is what head do people use?

small single, medium single, large single, or multiple "star" head?


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## markqf1 (May 24, 2008)

Carl,
I'm not an expert on the subject but, I do have a bit of experience with these animals. This oxy-acetylene torch is usually set up for cutting metal
or, certain types of welding such as braizing and sweating metals together.
The tip you choose to use is usually dependent upon the job you need to do. Since I haven't used it to melt any gold with yet, I wouldn't want to offer much advice here. I would think that the smaller tips would offer plenty of heat while narrowing the possibility of blowing any of your material out of your melting vessel of choice( don't hit the seperate oxygen lever). Also keep in mind that I have read too that acetylene is not the best choice for pgm's as it reacts chemically to form certain hard to break bonds. I think for gold it is fine though. I hope this helps you.

Mark


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## Oz (May 24, 2008)

I have welded with oxy-acetylene for over 25 years. Having said that, for welding I usually use a stick welder or mig these days. For cutting, you just can’t beat the oxy-acetylene. I’m not sure if I chose the best tip for melting silver, gold, or inquarting but I can share with you my logic in choice. To get the same amount of heat out of a small orifice welding tip you have a greater velocity of gases coming from the tip. So I have been using a cutting tip adjusted to a reducing flame. Just make sure you don’t hit the lever to throw the extra oxy like when cutting steel or you surely will scatter your PMs everywhere.


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## CarlClassen (May 24, 2008)

Okay that was a new experience for me! When I lit the torch for the first time It scared the beep out of me.

Lessons learned. 

1.	Get the lid off the borax BEFORE you turn the torch on
2.	Need either bigger Stainless steel jug or need to pour from higher level
3.	Goggles are good. I was happy I wore mine! Didn’t think it would get that bright.

I used the torch head on the left. Next time I’ll use the single small head on the right. I found the flame was very yellow. I was having a hard time figuring out how to get it nice and blue like in Steve’s video.

I had no idea what the lever does on the torch. The instruction booklet doesn’t help either. Thanks for clearing that up oz, markqf1. I won’t touch it.


The inquarted gold came out like pictured. Was in not hot enough? Or did I need to pour from higher up?

The crucible came out looking like crap. Can I reuse it? How do I recoat it? What did I do wrong?

When I turned off the gas cylinders I noticed that the oxygen pressure stays high but the acetylene slowly goes down. Can that mean I have a leak? I checked with soap and water before hand but didn’t find any.

Thanks for the help. 

[IMG:1024:768]http://i301.photobucket.com/albums/nn41/cdnArmy/Gold6K.jpg[/img]
[IMG:1024:768]http://i301.photobucket.com/albums/nn41/cdnArmy/TorchHeads.jpg[/img]
[IMG:1024:768]http://i301.photobucket.com/albums/nn41/cdnArmy/Cruicible.jpg[/img]


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## Anonymous (May 24, 2008)

Oz said:


> James,
> 
> Are you sure that is acetylene your burning? When I light my torch on acetylene only, it burns very dirty with carbon floating in the air until I kick in the oxy to get a clean burning flame. Some people even soot their molds with straight acetylene so the gold doesn’t stick when poured. If you were using compressed air with acetylene it might work, but it sounds like you are talking about a torch that operates like a plumbers propane soldering torch.



Yes, I am sure. My torch is made for it to breath air, you oxy/act is not it does not have breathers.

I do not buy oxygen, I do have a oxygen/acetylen cutting set up but never use it. It just takes up space in the truck.


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## draftinu (May 24, 2008)

Carl, You had numerous problems somewhere. The torch tip on the right is the one you need to use, the melting dish is junk, what did you inquartate? and don't use the trigger on the torch that is for cutting metal, not melting PM's. Good luck! And be carful! :shock:


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## Harold_V (May 25, 2008)

CarlClassen said:


> Okay that was a new experience for me! When I lit the torch for the first time It scared the beep out of me.


Did it pop? 



> I used the torch head on the left. Next time I’ll use the single small head on the right.


The head on the left appears to be a cutting tip. It is not the best choice for melting, but only because it is used in conjunction with a cutting head, which has the lever you spoke of. 



> I found the flame was very yellow. I was having a hard time figuring out how to get it nice and blue like in Steve’s video.


A yellow flame ( that's a reducing flame) is the result of too much fuel, and not enough oxygen. Depending on which torch body you use, you must adjust the proper valves until you get the desired flame. The pressure setting on your regulators is also critical. Start with something like 10 pounds of oxygen and 5 pounds of acetylene and see how it goes. Too much oxygen pressure is not a good idea, not even when cutting. 

If you can describe your torch to some degree, I may be able to provide guidelines on pressure settings. Your welding supply house should have some literature that would be helpful as well. 

A neutral flame would be desirable for melting gold. That would be a flame that has a blue cone, but displays a slight hint of yellow at the tip. The yellow is a sign of incomplete combustion of the fuel. 



> I had no idea what the lever does on the torch. The instruction booklet doesn’t help either. Thanks for clearing that up oz, markqf1. I won’t touch it.


The lever introduces excess oxygen, which in turn burns the preheated metal (steel) to make a cut. That type of torch body is not the best choice, although a tip of that nature is an excellent choice. There are Hoke torches available at jewelry supply houses that use just such a tip, although I'm not suggesting you should invest in one. Just a point of information. 



> The inquarted gold came out like pictured. Was in not hot enough? Or did I need to pour from higher up?


There is nothing about the material that looks right. 

Can you tell me what you melted? Did you use copper for inquartation? 



> The crucible came out looking like crap.


That's a melting dish, not a crucible. They are not the same thing. 



> Can I reuse it?


Yes---it is not destroyed, just dirty. 



> How do I recoat it?


The best procedure would be to heat the dish and introduce some soda ash, which will reduce the oxides and clean the dish. Once molten, you'd stir the soda ash to assist in the cleaning process, then add some borax to increase volume. You should see some small prills of metal form, which will contain some of your values. If you have access to an assayer's cone mold, pour the flux mixture in the mold while it's quite fluid. If the dish is still quite dirty, repeat. When you are satisfied that the dish is clean, recoat it with a little borax. 

Be advised, the cleaning process I mentioned dissolves a portion of your dish. Don't carry the operation too far. A clean dish, for inquarting, is not necessary. It will gradually become dark with oxides, and the flux cover getting correspondingly thicker and thicker. You can add some fresh borax to extend it's life, but it will eventually require cleaning as I prescribed. When you have exhausted a melting dish that has been used for inquartation, remember that the flux contained will have values. Do not discard the dish without going through the cleaning process I outlined. 



> What did I do wrong?


Hard to say. Detail what you melted, and what you used for inquartation. 

A casual glance tells me that you may have melted something that should not have been melted. 



> When I turned off the gas cylinders I noticed that the oxygen pressure stays high but the acetylene slowly goes down. Can that mean I have a leak? I checked with soap and water before hand but didn’t find any.


It is my opinion that you have a leak. My acetylene does the same thing, so I make a habit of keeping the bottle turned off unless it's in use. I suggest you do the same. I've never found the source of my loss, and I've had my regulator(s) rebuilt. 



> Thanks for the help.


Better save the thanks for the time when I have helped. Not sure I have in this case, but I'd like to. Tell us more. 

Harold


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## CarlClassen (May 25, 2008)

draftinu said:


> Carl, You had numerous problems somewhere. The torch tip on the right is the one you need to use, the melting dish is junk, what did you inquartate? and don't use the trigger on the torch that is for cutting metal, not melting PM's. Good luck! And be carful! :shock:



Ok I'll switch heads. I melted a mix of 14k and 10k Gold. I added silver to inquartinate.


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## lazersteve (May 25, 2008)

The dish looks more like a cupel to me. I use a standard melting dish or one of the larger hard white ones.

From the looks of the left over slag, there was lots of copper in the material and little or no silver (no white residue around the rim).

The color of the cooled material also does not appear to have been inquarted with silver, it typically has a silvery appearance with purple and dark colors mixed in. The texture is also wrong. The pieces should have come out more like cornflakes instead of random pieces of distorted alloy. You may be pouring the metal too fast from the looks of the material produced. Another possibility is that the metal was not fully molten.

Here's a photo of inquarted cornflakes made with silver:

[img:452:413]http://www.goldrecovery.us/images/275_inquarted.jpg[/img]

Steve


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## CarlClassen (May 25, 2008)

Harold_V said:


> Did it pop?



It was just the amount of flame that came out. I think i had the acetylene on too high. You could say it "poped"



> The head on the left appears to be a cutting tip. It is not the best choice for melting, but only because it is used in conjunction with a cutting head, which has the lever you spoke of.



I've switched heads for try #2.



> A yellow flame ( that's a reducing flame) is the result of too much fuel, and not enough oxygen. Depending on which torch body you use, you must adjust the proper valves until you get the desired flame. The pressure setting on your regulators is also critical. Start with something like 10 pounds of oxygen and 5 pounds of acetylene and see how it goes. Too much oxygen pressure is not a good idea, not even when cutting. .



Ok i was using a LOT less pressure. more like 3 pounds of oxygen and 4 pounds of acetyelne.



> If you can describe your torch to some degree, I may be able to provide guidelines on pressure settings. Your welding supply house should have some literature that would be helpful as well.



The torch looks exactly like Steve's from what I can see. I'll post a pic. Its a Power Fist Harris Style Medium Duty Welding & Cutting Kit. God now that i rereading the instruction I see that since I'm not using the cutting tip i don't install it at all.



> A neutral flame would be desirable for melting gold. That would be a flame that has a blue cone, but displays a slight hint of yellow at the tip. The yellow is a sign of incomplete combustion of the fuel.



Ok



> There is nothing about the material that looks right.
> 
> Can you tell me what you melted? Did you use copper for inquartation?



Well it was 10k and 14k with silver used for inquartination. The material I got looks gold with purple.




> That's a melting dish, not a crucible. They are not the same thing.



Oh, whats the difference?



> You should see some small prills of metal form, which will contain some of your values. If you have access to an assayer's cone mold, pour the flux mixture in the mold while it's quite fluid.



I don't have an assayer's cone mold. Can i pour the flux mixture into water to extract the material that way?

I really appreciate the help.


Torch without cutting tip
[IMG:1024:768]http://i301.photobucket.com/albums/nn41/cdnArmy/Picture026.jpg[/img]


Torch with cutting part taken off
[IMG:1024:768]http://i301.photobucket.com/albums/nn41/cdnArmy/TorchBottom.jpg[/img]

Part I'll attach to above
[IMG:1024:768]http://i301.photobucket.com/albums/nn41/cdnArmy/Picture027.jpg[/img]

Regulators
[IMG:1024:768]http://i301.photobucket.com/albums/nn41/cdnArmy/RegulatorHeads.jpg[/img]


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## CarlClassen (May 25, 2008)

lazersteve said:


> The dish looks more like a cupel to me. I use a standard melting dish or one of the larger hard white ones.
> 
> From the looks of the left over slag, there was lots of copper in the material and little or no silver (no white residue around the rim).
> 
> ...




Hmm well its quite possible I got the wrong thing(cupel). When i went to the store to buy it the person who was working knew less then I do 

Well i'm pretty sure i put the right amount of silver in. It was about half silver pellets. I did do the exact measurements though.

I think i poured too quickly and from too short a height. The metal hit the bottom of the stainless steel water jug i had. 

Thanks for the picture. That helps me figure out when i have done it right.

Here is the type of silver i used.

[IMG:1024:768]http://i301.photobucket.com/albums/nn41/cdnArmy/Silver.jpg[/img]


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## Harold_V (May 25, 2008)

CarlClassen said:


> It was just the amount of flame that came out. I think i had the acetylene on too high. You could say it "poped"


Popping is a sign of a back flash. It's loud, and usually blows out the torch. The flame from an oxy/acet torch is, indeed, a bit intimidating. I used natural gas and oxygen instead, which yields a considerably softer (and cooler) flame. 



> I see that since I'm not using the cutting tip i don't install it at all.


That's correct. The welding tips screw on the body directly, and the portion with the lever is removed. Once you have it down to that assembly, you can easily adjust the oxygen/acetylene for the type of flame you need. The main body has only two valves, while the cutting torch includes a third valve. it's an oxygen valve. I suggest you use the largest tip and run it at lower pressure. That will yield a volume of heat without excessive velocity. Blowing the gold out of the dish when you melt gold powder is a real possibility. When you melt the powder, hold the torch well back and allow the feather at the tip of the flame to melt the surface of the powder. Move closer only when it has been well melted. Otherwise you'll lose some values. Be advised that melting the powder is usually the source of small losses. You'll see the occasional flash, which is generally a miniscule ball of gold flying out of the dish. I melted in a container and recovered most of the losses as tiny gold balls. 



> Well it was 10k and 14k with silver used for inquartination. The material I got looks gold with purple.


The color really troubles me. I don't recall ever having results like you achieved. What I'm thinking is that something you melted wasn't what you think it was. Did you find it wouldn't melt easily? Did you continue to heat the material after it was molten? I don't understand why there's so much dark material in the flux---a sign that you either super heated the material, or you melted something that wasn't a gold alloy. Was the gold (I'm assuming it was gold) a strange color? Blue or purple gold, in other words? Gold is normally yellow, white or rose colored, with green gold included on a limited basis. The elements that make gold purple or blue can be troublesome------which is why I ask. 

Harold commented:


> That's a melting dish, not a crucible. They are not the same thing.





> Oh, whats the difference?


Crucible are cylinders, or modified cylinders. The common type is what is referenced as a bilge crucible. It is widest at roughly the mid point, with a small base and slightly smaller opening at the top than the bilge diameter. They are also made as a true cylinder, or a simple taper, with the top the largest, tapering down to a more narrow base. In almost all cases, they are taller than they are wide, and will contain a large amount of material. They can be made of clay, but are more commonly made of graphite and clay mixed, or silicon carbide. They are normally used in conjunction with a furnace of sorts----they do not lend themselves well to torch melting the way a dish does. Crucibles, for the record, come in a vast array of sizes. Some are no larger than a walnut, while others are large enough to contain hundreds of pounds of aluminum. Size, once they get above the miniatures, is based on their volume in aluminum. A #2 holds 2 pounds of aluminum, just as a #500 holds 500 pounds of aluminum. 



> I don't have an assayer's cone mold. Can i pour the flux mixture into water to extract the material that way?


That might work, but you'll work harder at finding the prills, assuming they don't agglomerate. The idea behind an assayer's mold is that the values collect at the bottom, with the slag on top. If the slag is fluid enough, all of the values collect in one place. 

As an alternate, you might consider using a short piece of angle iron. If you can cut it at an angle, then weld a pair of plates on each end, you can make what would serve as a cone mold, only elongated, It need not be very large----you deal with small amounts when working with a melting dish. The one thing that would be important is that the angle iron have sufficient wall thickness to absorb the heat without getting over heated. Otherwise the values may solder to the mold. Assayers cone molds are made of heavy cast iron to avoid that problem. If you make a mold as I suggested, coat it with soot from your torch by lighting the torch with just acetylene turned on----then play the torch on the mold. It will coat instantly. Be sure you have preheated the mold, so no moisture collects. That's an open invitation for a small steam explosion when you pour the flux and recovered metal. 

The pressure settings I suggested may not be proper for your torch---it might pay you to experiment a little. 

Harold


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## CarlClassen (May 25, 2008)

> The color really troubles me. I don't recall ever having results like you achieved. What I'm thinking is that something you melted wasn't what you think it was. Did you find it wouldn't melt easily? Did you continue to heat the material after it was molten? I don't understand why there's so much dark material in the flux---a sign that you either super heated the material, or you melted something that wasn't a gold alloy. Was the gold (I'm assuming it was gold) a strange color? Blue or purple gold, in other words? Gold is normally yellow, white or rose colored, with green gold included on a limited basis. The elements that make gold purple or blue can be troublesome------which is why I ask.



I think there is a good chance I over heated it. It melted really easily. The gold was just plain yellow gold chains all marked.



> The pressure settings I suggested may not be proper for your torch---it might pay you to experiment a little.
> Harold



The pressure setting were perfect. With those and the max single torch head I got a perfect flame right away!

The rest of the information you gave is going to be very useful. Thank you for taking the time to respond in such detail.


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## Harold_V (May 26, 2008)

CarlClassen said:


> I think there is a good chance I over heated it. It melted really easily. The gold was just plain yellow gold chains all marked.


Over heating could be the problem, but so, too, could the chance that the chains were not karat gold, but gold filled. In that case, you would have a preponderance of base metals, which would oxidize badly when over heated. If your yield comes up short of gold, that is likely what you may have melted. Chains can be tricky---they are marked only with an attached tab---and could easily be faked by unscrupulous individuals. 

I mentioned the color. There is also the chance that you used an extremely oxidizing flame. It would have had a pale blue inner cone, and likely had a loud hissing noise. Such a flame will rapidly oxidize your metal. When melting gold, try to keep the flame ever so slightly reducing, displaying a hint of yellow. 



> The pressure setting were perfect. With those and the max single torch head I got a perfect flame right away!



Very good news! I think you're going to enjoy having the torch. They are capable of some serious temperature----around 6,000° F as I recall. Gold and silver alloys melt almost instantly under such a flame, so your work is cut short. 



> The rest of the information you gave is going to be very useful. Thank you for taking the time to respond in such detail.



Welcome. :wink: 

Harold


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## The Refiner49er (May 26, 2008)

Hey All-

I just wanted to put my two bits in on this subject.

If you have to use a cutting torch to melt your gold, what works as a safety to prevent operation of the oxygen lever is a wedge (wood or whatever) inserted between the lever and the body of the torch. This will eliminate the risk of unintentional blasting of the gold from the dish.

John


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## Oz (May 26, 2008)

It is probably worth revisiting the oxy/acetylene cutting torch head again. As Harold very rightly pointed out, a Hoke torch with a tip like you have on an oxy/acetylene cutting torch is ideal as with melting PMs you will never need the lever for excess oxygen. These tips give high heat at low gas velocity saving you from blowing away and loosing fine PMs.

If you are sure that you will never want to weld or cut steel by all means buy a Hoke torch, but in my opinion it is nice to have the added versatility of being able to do steel work. Harold gave very good advice as to pressure ratios and the adjustment and look of the flame you want for melting PMs. Honemaster gives a good tip on using a wedge to disable the lever. 

If you are setting up an oxy/acetylene torch for cutting you would start with all 3 valves closed on your hand piece. After setting the pressures on your regulators at the tanks (pressures are set significantly higher for cutting than welding or heating) you then fully open the green (oxygen) of the 2 knobs at the base of your handset. You then crack open the red valve at the base (acetylene) and light it with your striker. Then you crack open your 2nd green knob at the top of your handset. You adjust the top green and lower red knobs until you have a good heating flame. You then start to heat your steel until you start seeing some puddling where you want to start your cut and depress your lever. This will give you the full pressure you have available to you from the setting you have on your regulator on the oxygen tank. This extra oxygen actually burns the steel and blows the slag out of the bottom of the cut.

Now we are not doing this here but I thought it worth explanation as there are some just learning this equipment and it helps explain what the controls they have available to them do. You can see why the lever is to be avoided in melting precious metals.

As Harold has pointed out the tip is ideal here just not the cutting handset due to the risk of accidentally hitting the lever if inexperienced. Honemaster suggested you wedge it so it can’t be activated, I just keep the web of my hand under the lever. Each of you will have to decide whether or not you will ever want to work with steel. I for one would not want to live w/o this capability for about the same cost as a Hoke set-up. Just as Harold talked about making a quick cone mold from angle and plate for recovering the values from fluxes, you have the tools in hand to make quick work of it with oxy/acetylene. 

Although I have not done it, I understand that you can run hydrogen through the same rig instead of acetylene which would be nice for platinum group metals. Maybe Harold can share some details on the use and advantages of hydrogen. 

It would also be worth mentioning that a pair of flashback valves at the base of your handset and again at the output of your regulators at the tanks is a good idea and cheap insurance. It is not a great risk, I was even taught years ago to shut the acetylene of first to give the loud “crack” blowing the tips clear in the process but it is better to err on the side of caution. It is also worth noting that when you are done always shut the gasses off at the main tanks, relieve the pressure on the gauge springs by backing them off, and shut all the valves on your handset. In those positions you have 3 points of shut-off, have saved undue stress on your gauge springs, and the handset valves have less chance of corroding at the seat points being tightly mated.


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## CarlClassen (May 28, 2008)

Harold_V said:


> [
> 
> 
> 
> ...



Ok i used soda ash and reheated and poured. Does prills look like sand once seperated? My water container looks like it has "gold" sand on the bottom.


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## Harold_V (May 28, 2008)

That may well be some of the material you melted originally. Prills are nothing more than tiny droplets of metal that don't combine to form a larger mass. Thick slag is one of the reasons they don't----or not enough time in the molten state to allow them to come together. There's not much you can do aside from heat the material long enough-----or to use a cone mold. Sorting the values from the junk will be a tough job. You might consider boiling the pieces in dilute sulfuric or HCl to eliminate the flux--------or simply re-melting everything with more soda ash and borax. Once molten, stir the dish and try to make the tiny button that should form come in contact with the other tiny bits. They'll readily join one another if they make contact. 

I hope you see the wisdom of using a cone mold instead of pouring to water. 

Harold


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## donald236 (Jun 2, 2008)

hey guys, I'll be honest, im dumb founded when it comes down to knowing the difference between the different gases for torches . so Ive read it or heard it some where that mapp gas is a real good source for melting gold . so i bought a torch kit . did i do good or bad :?: :?: :?: 
thanks in advance


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## Harold_V (Jun 3, 2008)

MAPP gas is expensive, but otherwise probably OK. Without oxygen it won't perform as well as you'd like, however. Probably impossible to melt platinum with one. 

One of the best gasses you can choose is natural gas. Most Hoke torches are made to operate on the stuff, so all you need is an oxygen cylinder, regulator, and you're in business. I used a large Hoke torch to melt everything, including platinum. It's desirable to use a fuel that is low in free carbon when melting the platinum metals to avoid creating carbides. A hydrogen torch is ideal. 

Harold


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## donald236 (Jun 3, 2008)

well the kit included the gas tank and the oxygen tank plus hoses and everything . even the stricker


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## Harold_V (Jun 3, 2008)

If you have natural gas at your disposal, it might pay to see how it would run with your torch when the MAPP is exhausted. If it works, it will save you a ton of money.

Knowing you have oxygen makes a huge difference. You'll like the torch, you just may not like the cost of operation. I'd say you did just fine!

Harold


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## donald236 (Jun 3, 2008)

thanks harold and i will look into the natural gas thanks so much 
brother your a biggggggggggggg help to this forum .


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## AKDan (Jun 3, 2008)

The type of tip you guys are looking for, for use with Nat gas, Mapp, Propane or acetylene is called a "Rose Bud" It looks much like a cutting tip in that it has multiple holes and the flame coming out the end looks like a Rose Bud in shape. They are not welding tips or cutting tips but are intended for heating/melting only. Actual use is for pre-heating metals before welding. You will get the same type of concentrated heat that you have with a welding tip (single hole) but multiplied over a wider area. No chance of hitting the oxy cutting lever and blowing your material all over the country. They are pretty spendy from what I remember, but probably worth it for not overheating specific spots on your PM, or melting dishes quite so easily. Also, melting will be faster, more consistent, and it is easier to keep the metals liquid when pouring.

Pretty much any gas that will burn, when combined with oxygen, will make the heat needed to melt. It is a question of application and over what time period. As well, any of the fuels will add carbon if the flame is not adjusted to the correct size shape and type. Carbonizing flames will be tri-colored and look soft. Neutral shape should be bi-colored, crisp looking with only very slightly (at the most) feathered edges on the internal cone of the flame. Oxydizing flames will have a very sharp cone shaped internal flame and are noisy with respect to the other two flame types described. Acetylene will self ignite very easily, and under varied conditions. Please do some research before you experiment with your torches. Not a pretty way to go. OXYGEN WILL SELF IGNITE/EXPLODE in the presence of ANY oils. Also not a pleasant experience.


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## donald236 (Jun 3, 2008)

hey thanks for the (rose bud tip ) advice


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## Harold_V (Jun 3, 2008)

donald236 said:


> hey thanks for the (rose bud tip ) advice


AKDan's comments are spot on! 

I used the large type Hoke torch he mentioned, and was successful in melting platinum with little effort. I used it for melting my gold powder (using a tip dedicated to that process only), and also for inquarting. You can easily melt 20 troy ounces of metal with the large torch. Keep it in mind if you find yourself processing large volumes. The smaller Hoke torches, or the one you purchased, should serve very well for moderate sized batches of metals. 

Harold


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## grainsofgold (Jun 8, 2008)

I like Hydrogen and 02 for melting as its burns clean and is fast to heat up. 

Next to that I would recommend propane and 02 for melting as a general mixture. You can use a bar b que refillable bottle and get them at most hard ware stores or garden supply shops. 

When you start a torch set up from ground zero- 

1) I recommend buying hoses in the lengths you need with factory fitted end pieces. 

2) Next buy a good regulator for the Oxygen and one for the type of gas you are going to use. Ask where you buy the hose they can tell you (welding shop)

3) If you buy used torch equipment be sure and have it thoroughly gone through and cleaned by an expert = we have one in our town and the small cost might just save your life-

4) Anchor the bottles to a wall with a chain if possible. Always have your bottles standing, never lay them on their sides.

4) Bottle/regulator fittings are brass on brass therefore you should not use Teflon tape to stop air gaps from the bottle to the regulator 

5) With the bottles connected to the regulators and the torch hoses connected to your regulators , next turn off the torch 02 and gas knobs. Leave the regulator pressure where it doesn't put pressure on the 02 or fuel, then open the bottles and carefully tighten the regulator pressure valves to about 5 lbs. 

6) at this time 02/fuel should be coming out of the bottle, through the regulator and into the lines stopping right before knobs for turning on /off the fuel 02 of the torch.

7) get a cup of water and add dishwater soap to it making it sudsy-

8) take a wash rage or paint brush and dip the sudsy water from the cup and then over where the regulator screws onto the bottle - if there is a leak bubbles will keep coming from the area-

8) next check where the hoses connect to the regulator for the same thing-

9) next check for the connections on the on/off knobs of the torch.

If all this checks out then turn off your bottles leaving pressure in the hoses. Then check the necks of each bottle to see that the main cylinder valves are not leaking. If they leak exchange them for a new one- I get about 6 bottle a year that leak at the necks - The company I use once in a while lets them get refilled without checking them for leaks- STUPID!

10) If the necks are good, then turn back on the bottles and open the torch fuel knobs and before you light anything , take the rag and check the area that the handle connects to the body of your torch- If there are no leak, fire it up. 

11) At most welding stores you can buy a cheap flame starter aka Flint striker - be sure and buy a packet of spare flints to have when needed-

12) with the flame lit go slow with it and get the feel of the weight of the torch and be sure and concentrate- It is very easy to swing a torch around an burn yourself or something that does not need to be burned.

13) Once you get the feel, then gradually increase your o2 and fuel pressure via the knob on the regulators - Yellow tip flame is reducing and blue tip flame is Oxidizing- 

14) When you where at the welding store , you should have bought a good pair of welding goggles and a heavy pair of heat resistant gloves. 

15) Never wear loose clothing or wear a tie when you are working with a torch-

16) any powders or liquids you want to use be sure and remove the lids and place these in position prior to lighting your torch.

17) If you are going to make shot out of your inquartation do it in small batches at a time, then do a pour from a higher position (stand on a steady step stool with another person there to help you and hand you the torch into a tub of ice cold water- A horse watering steel trough or a 55 gallon barrel will work well also- Some folks like to agitate the water also - As long as the end result are open type kernels of inquarted gold who cares how pretty they - so long as they get the job done- 


If you use natural gas as your fuel- it is hard to get enough pressure to make it worth anything for large melts- City gas comes to homes in oz rather than in lbs. When I set up my new shop the city installed a high pressure line for me for a added fee- makes all the difference in the world- If you cannot get a high pressure line from your gas company there are devices you can buy that are called "line boosters". Ri0 Grande supply in AZ sells these - 

When you are done, ALWAYS turn off your bottles and bleed your lines. 

I am sure I may ave missed a thing or two so please feel free to add your .02ct-


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## istari9 (Jun 8, 2008)

As a welder with 25 years experience I would not choose a Rose Bud uses too much gas at too high a pressure. I would consider a welding tip they are designed to heat hot enough. Also remember the temp gold vaporizes, you may find that important. 
There are two types of hoses for torches one is a heavy duty type which is great for going from tanks to the work the other is a smaller more flexible type. This gives an easier movement at the torch. Is very easy to burn your self fighting the heavier hose at the torch. 
I also suggest buying some back flow preventers, they are a nice safety feature. For those of you not familiar with the melting and control of melted metals, I would suggest using some steel to melt for practice. It would familiarize you with torch operation and control. 
I own and use an air gas torch, for lighter welding projects like soldering and such. I personally would use the oxy/gas mix for a bit hotter flame and more control. Make sure your cutting tip or welding tips are clean before you start work, a clean tip has a dirty sound. 

Ray


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## goldsilverpro (Jun 8, 2008)

I've known a ton of professional refiners and, without exception, they all preferred a rosebud tip for torch melting gold.


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## Harold_V (Jun 8, 2008)

goldsilverpro said:


> I've known a ton of professional refiners and, without exception, they all preferred a rosebud tip for torch melting gold.


I agree. The difference is that the rosebud generally is for Hoke type torch, not a welding torch. That type torch is troubling, to say the least. 

I used a Hoke type for years and found it to be excellent for melting, a huge step up from the common bench Hoke torch. 

I don't claim to understand the differences between those made for the jewelry industry and the welding industry, but many of the problems of the typical rose bud don't seem to be a problem with a Hoke torch. I recommend the Hoke torch highly. 

Harold


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## istari9 (Jun 8, 2008)

I must needs look into that (RoseBud) and ck it out. Thanks for the tip!
Ray


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## scwiers (Aug 27, 2008)

Harold, when you recommend the Hoke torch w/ natural gas, is that gas at the pressure delivered up the pipes at 'standard' household pressure (because I know that industry often has it metered up much higher)?

If I can get an O2 setup with the Hoke torch, plus valves and regulators, and run it off city gas, (plus get the city to pay for it :twisted: ) then I'd be all set...

(get' em to pay for the O2 this coming winter, too...)


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## qst42know (Aug 27, 2008)

Some of your melt problems are related to your regulator settings. They should always be in a two to one ratio. 7 psi gas and 14 oxygen is about minimum and will cover almost any job except heavy cutting or large rosebuds. Adjust your regulators with the torch valves open a bit so the reading are true when operating. A reducing flame is a soft quiet flame with two feathers at the tip, a little more oxy and the feathers just blend together into a neutral flame, a bit more oxygen for an oxidizing flame the feather sharpens brightens and has an angry hiss to it. Don't bury the tip in the work and take your time. Steves avitar has a nice roll to it not to far and not to close. You can hold your metal at this point and practice moving it around nice and fluid then you know its well blended.


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## Harold_V (Aug 28, 2008)

scwiers said:


> Harold, when you recommend the Hoke torch w/ natural gas, is that gas at the pressure delivered up the pipes at 'standard' household pressure (because I know that industry often has it metered up much higher)?


In my case, I had one pound delivery (at the torch, and at the melting furnaces), and regulated down (to I think 4 ounces) at the two furnaces that heated that side of the castle. What ever is considered normal for residential is what I had, just in case I am wrong with stating it was 4 ounces. 

The one pound delivery was at special request, and mandated I must regulate to lower pressure for commercially available residential heating appliances. 

Pressure isn't as much an issue as volume, which is why gas piping is so large. With low pressure (4 ounces), if you provide a large enough pipe, the pressure won't be an issue. I would expect that you could get by nicely with 3/4" pipe, maybe even ½". 

Torches that are intended to be used on natural gas are gauged accordingly (tips for natural gas are different from tips for other fuels). You should be able to achieve success with standard delivery. Many of the benchmen use natural gas for their torches with no problems. Could be one of them would chime in if I've missed the boat here. I'm guilty of having been away from my old installation for many years now, and memory is growing dim. 

One thing I will assure you is you won't be sorry to have a natural gas supply. The only negative is it's worthless for smoking molds when casting ingots. I had to use my oxy/acet rig for that purpose, but I didn't regularly cast ingots. Virtually all of the gold I dispensed was in the form of shot, which is preferred by those that use gold for making jewelry. 



> If I can get an O2 setup with the Hoke torch, plus valves and regulators, and run it off city gas, (plus get the city to pay for it :twisted: ) then I'd be all set...



No regulator required for natural gas. Install a gas valve with the proper connection for your hose (I used the acetylene hose, connected to a hose barb with a hose clamp (the barb mounted directly in the valve). It's already regulated. You'll discover that the cost of fuel is negligible, even if you use your torch regularly. Oxygen will be the most costly, and even that isn't bad. I used to run for about three weeks on a large (245 cu. ft.) bottle of oxygen, and I was refining on a constant basis. I was getting the bottle filled for about $16. A small bottle, used intermittently, may last you for many months. 

Remember, I used my torch not only for melting (inquartation and melting pure gold), but for assistance in incinerating waste materials. My torch got used considerably, daily. 

If you're interested, I have posted, below, a picture of my hood. If you look closely, you'll see how the torch was hooked up. The regulator was for oxygen, with the gas valve more or less hidden behind the oxygen regulator. The torch is next to the hood. Sorry for the messy appearance. The lab, by now, was in total disrepair and in bad need of painting. Picture was taken just before everything was removed after selling the business.

Notice the staining and general corrosion on everything. That's the result of ten years of constant use, even with the hood operating almost non-stop. 

Hope some of this helps.

Let us know how it goes if you venture forth. 

Harold


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## grainsofgold (Aug 28, 2008)

natural gas pressure comes into play when you need a hot flame for melting platinum - If you do not want to wait a long time to melt only a small amount of pt you will need a high pressure natural gas line -


They also make natural gas booster devices which you can buy from Rio Grande 

Or better yet - use Hydrogen and Oxygen and you will not be sorry 


Propane will work also but having propane tanks in a building is a no no - most codes require that you have a propane tank outside and plum the gas into a building- Propane is a heavy gas and settles lower which is the conern-


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## goldsilverpro (Aug 28, 2008)

I've used H2/O2 quite a bit. It was nice but I hated not being able to see the flame. I think my all time favorite is natural gas. Acetylene is dirty, but like Harold said, it's great for smoking molds. I can easily live with acetylene, if I'm only melting gold. Basically, I'm not a torch person, although I have torch melted 1000s of ounces of gold. I love a natural gas crucible furnace most of all. Fast (after it's hot), large capacity, you can easily clean up off-purity gold, and you can easily melt silver or copper, also.


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