Non-Chemical Another DIY furnace

[Nervin]

Hello all, This is my first ever post and I would like to appologize ahead of time if I cross any boundaries

I am partnered with my dad on Gold and precious metals hobby only I am more of the pyro in the this partnership. In my venture to try and find a way (still working on it too) to make a nice furnace that isn't too expencive and can melt most metals, I ran into this one and thought I would drop it in here for anyone looking to experiment. http://incolor.inetnebr.com/bill_r/fun_with_molten_metal.htm it looks like it is pretty cheap to make and my understanding on obtaining high temps is in the refractory and the burner nozzle.

I am already familiar with the back yard metal casting kit http://www.backyardmetalcasting.com/hmkit.html but I am trying to see if anyone has built one and had have refractory delivered to them. The reason I ask this is if it is going to cost just as much to build it as to buy one already built like from here http://www.abprospecting.com/sitebuildercontent/sitebuilderfiles/pg19.jpg then I would rather be lazy I guess. I have posted on backyard metal casting but it seems not many are into the pyro for refining, and those who are have monster furnaces. Since I am just doing it for melting gold, silver, ect.. into ingots I won't be doing huge melts then the monster furnace isn't in the budget for me.

Also has anyone melted Platinum? Would like to know if it could be done in a furnace.

I have searched google and the forums for most of this info and it has been three nights of staying up til 5am. Any help would be awwweeesome and would definitley lower my coffee budget :lol: or just point me to a different link or forum that I have somehow overlooked.

 

[Harold_V]

Also has anyone melted Platinum?

Several of the readers have, as have I.

Would like to know if it could be done in a furnace.

Yes, it can be done in a furnace, but you are unlikely to be able to achieve the required temperature. Induction heating can do it, although they are typically beyond the reach of the average guy. Achieving a temperature that will melt steel (let alone platinum) is very difficult in the typical gas fired furnace. Torch melting is generally adequate, although you must use a melting dish intended for use in melting platinum due to the high melting point involved. Frankly, accumulating enough platinum to make melting a problem isn't likely to happen. I acknowledge that I can be wrong about that.

Sorry I'm not more help.

Welcome to the forum.

Harold

 

[Nervin]

Thank you for the replay Harold,
Yea I have looked at a few of the induction furnaces and the prices are nightmarish.

I actually found a place in Nashville that sells casting refractory so I can skip the shipping charges (although I would have to go to knoxville to pick it up), but this gives me the option to pick the maxx temp refractory that I want.

So a forced air burner wouldn't help get the temps that I would need to reach?

So has anyone on here built one using the kit? Would it be hard to get a thermocupler installed? Any tips or advice before I subject myself to this adventure?

 

[Barren Realms 007]

Thank you for the replay Harold,
Yea I have looked at a few of the induction furnaces and the prices are nightmarish.

I actually found a place in Nashville that sells casting refractory so I can skip the shipping charges (although I would have to go to knoxville to pick it up), but this gives me the option to pick the maxx temp refractory that I want.

So a forced air burner wouldn't help get the temps that I would need to reach?

So has anyone on here built one using the kit? Would it be hard to get a thermocupler installed? Any tips or advice before I subject myself to this adventure?

You can probably find a 4-20ma thermocouple if you can get a reader for it. I would be interested in knowing about the place in Knoxville with the refractory if it for the high temps. I have a friend around Jackson that can pick it up for me. Do you have a web address for them?

 

[Nervin]

The office is in Nashville


Empire Refractory Specialists‎
Ste A, 2832 Logan Street
Nashville, TN 37211-2473
(615) 331-2403

You have to call them to get things started, but you have the option to have it shiped to you or you can go and pick it up. They have warehouses in Knoxville and I think Memphis too which would be good for Jackson side. When I asked if I could just pick it up to save on shipping he said absolutely. I ended up settling for Kast-O-lite 30 LI rated at 3000 degs Insulating Castable Refractory for $78.00 a bag. Doesn't seem so bad concidering if it's shipped it costs a ton. They have higher temp castables too but they cost twice that, like GREENCAST 97 at 168.00 per bag but it's rated at 3400 degrees..

 

[Barren Realms 007]

Thanks for that info I will look them up in Memphis since I am close to there.

 

[Nervin]

You would still have to call the Nasville office. they seem to be the central ordering office for Tennessee. Unless you are near Alabama, then they have thier own offices and warehouses.

 

[Barren Realms 007]

Ok thanks for the info.

 

[rbramsey]

http://www.empire-refractory.com/index.htm

They have offices in Birmingham area

Richard

 

[lazersteve]

Empire is where I get all of my refractories, they are good people and easy to deal with. Be sure you know what you are ordering or you may end up with the wrong refractory.

My first blind order was not well suited to the project I had planned for it, so I ended up ordering a second time to get the right stuff. I did a little research to find out which refractory was best suited for my project and the second order worked just fine for the job.

The various refractories have different aggregates, binders, and/or fibers in them which give them different casting characteristics. Another important aspect to consider of the castable refractories is the amount of water used and the proper drying cycles.

Steve

 

[Barren Realms 007]

Empire is where I get all of my refractories, they are good people and easy to deal with. Be sure you know what you are ordering or you may end up with the wrong refractory.

My first blind order was not well suited to the project I had planned for it, so I ended up ordering a second time to get the right stuff. I did a little research to find out which refractory was best suited for my project and the second order worked just fine for the job.

The various refractories have different aggregates, binders, and/or fibers in them which give them different casting characteristics. Another important aspect to consider of the castable refractories is the amount of water used and the proper drying cycles.

Steve

What did you finaly come up with on the one you had in the thread where you had the bleed thru of the temps.?

 

[lazersteve]

I used ITC-100 to coat the refractory and reduced the temperature a little. I also tightened the throat of the opening in the top which keeps the direct heat off of the lid.

She's still hot, but not as hot on the surface.

Steve

 

[Barren Realms 007]

Glad you got some of it worked out then.

 

[Nervin]

Thank you for that infor Lazersteve, I looked into the ITC-100 and actually found one of the higher grade coatings that says it increases refractance.. I will definitely look into doing the coating. Lazersteve, I assume you did the standard burn-in of the refractory before putting the ITC on right?

I will definitely be going with Empire though, the prices are great.

I am on lionel's Ladboratory forum and although they are greatly well versed in metal melting and forging, I am actually being told that the Hobby melter kit would be over kill, and suggested just using a torch because they say a furnace would have more loss. I know that with a torch you have to be very careful not to blow the powdered PMs out of the crucible. I figured it would be safer to use a forge as everything would be heated up and red before you would even put in the borax and PM. Does anyone on here use the build it yourself hobby melter for their final melts? Has anyone had a noticable loss?

I know that as far as melting platinum I am stuck using a torch because unless the furnace is specialized (i.e. waste oil burner with heat exchange, or inductance furnace) the propaine or hobby furnace just isnt going to reach the temps needed. Plus the more I look into metal melting I may get into fabricating and molding as well but I don't think I am ready to build a furnace ready for the higest temp metals just yet.

Right now I am researching several aspects before I get my hands into it. Like temp capabilities of Gases and refractory (now the ITC layer), the shape of the chamber in order to achieve a more efficient heat-up and melt (learned that certain spiraling chamber shapes will focus the flame onto the crucible) and of course crucibles (I think that carbon is the best so far but if I am wrong please let me know). Then there is the sand mold versus carbon ingot molds.. (Kinda afraid to get sand stuck into the gold)