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melting copper

PostPosted: Wed Oct 05, 2011 12:58 pm
by needler420
Can a charcoal fire from a grill reach 2,000 degrees?

I read online a small fire would melt small amounts in a long period of time.

Also if a charcoal fire would work what do I use as a crucible to melt the copper in and what do I use to poor it in to. Also what kind of tongs would I need.

I'm not trying to do anything large scale here the most id would melt of any metal at once is like a pound. Mainly want to do pound and half pound ingots of copper.

Maybe get into some scrap .925 silver as well. I won't touch the gold as its too precious and too much money to risk playing with. The gold can go to the refiner should I obtain some.


I mainly need help from the guys who melt copper on a small scale. I'm not scared of any of the tools but I still want to be taught how to do it safely molten metal is some serious stuff just thinking of the kind of injury really puts things in perspective.

I'm also on a budget I need to try to get all my tools from my garage or yard/scrap sales. My budget to start this project is about $50 bucks lol though it sounds like a joke Iv been researching this now for months so I know I can make something in that budget work. Iv seen youtube homemade foundries made on a cheaper budget that were effective at accomplishing its job. Probably means safety gear is going to be real limited which isn't the best way to start but its the only way for now.

Re: melting copper

PostPosted: Wed Oct 05, 2011 1:57 pm
by SoFa
According to Wikipedia, a charcoal fire burns at 750-1200C.

You need to do a lot of research before you start this.

Re: melting copper

PostPosted: Wed Oct 05, 2011 2:00 pm
by kagarise
hmm im not sure how hot charcoal gets i've cast pewter off of it many times but pewter has a very very low melting point
the only times i've ever cast other metals i used a accetalyne [sp?] torch
you've probably seen it in your research but just for safetys sake i have to tell you
make sure there is no moisture in whatever form or mold you are casting into
people had told me that many times but i was like yeah sure whatever and didnt really listen
well a few years ago i was in the basement workshop casting 2000 coins for a living history group i work with
im still not certain how the water got into the ingot pan and i wasnt paying as much attention as i should have been but when i pulled it out and poured the metal in it was like [bBOOM[/b] i had tiny bits of pewter flying around the room no injurys but it taught me a lesson haha

Re: melting copper

PostPosted: Wed Oct 05, 2011 2:21 pm
by needler420
Well so far then my biggest problem to start with is going to be capable gear getting to a 1980 degrees.

So with a $50 dollar budget can I achieve 2000 degrees?

Re: melting copper

PostPosted: Wed Oct 05, 2011 3:00 pm
by kagarise
so been tossing this around in my head a bit
you can get away with charcoal if at all possible use lump charcoal rather than the kingsford style charcoal briquets
you're going to need a decent blower you may be able to get away with a hair dryer but we use an old leaf blower for our forge
its one of those yes i think you can do it for $50 but in suggest investing some decent money in some safety gear

what are you using for molds?
if it were me i'd use sand

Re: melting copper

PostPosted: Wed Oct 05, 2011 3:33 pm
by fasteddy
If it was me I wouldn't mess with it....oh...I don't and I have metal melting abilities...If your serious then you have some learning to do...and youtube isn't going to get it done.

Re: melting copper

PostPosted: Wed Oct 05, 2011 3:48 pm
by NiBullionCu

Re: melting copper

PostPosted: Wed Oct 05, 2011 4:15 pm
by Rodebaugh
50 bucks will buy just a few 2nd degree burns...... your going to need at least a grand to get up to that 3rd degree skin graft level.

Re: melting copper

PostPosted: Fri Oct 07, 2011 10:39 pm
by 0000PaleHorse0000
I would only proceed, IF you had proper equipment, including real safety equipment. A real good blower would get a charcoal fire pretty hot, but the main concern is making sure you don't burn your skin with molten metal. I'm all about DIY, but make sure you do it smart. All it takes is 1 small drop of water to make a nice explosion.

I'm not trying to talk you out of it and I'm not saying your not intelligent enough to weigh the risks, I'm just saying it should work with a nice, steady flow of oxygen. Just don't want you to burn yourself over 50 bucks of copper. I would like to see it if you decide to do it. I have been working on my own foundry and it's pretty rewarding.

Re: melting copper

PostPosted: Sat Oct 08, 2011 12:24 am
by brexzz1
Would anyone know the cost of having a foundry melt copper for you into bars?

thanks

Re: melting copper

PostPosted: Sat Oct 08, 2011 12:52 am
by wagsthadog
Hi there-

I agree with your ideas, but I don't think you will be able to do this safely and with good results on a budget of $50. I think you'll have to pony up about $400-$600 to be able to do this reasonably-

-Have you looked at getting a small jewelry kiln or desktop furnace? I am pretty sure they have ones that go up to 2000F.
Heavy Duty goggles (you might even want a metal face shield), heavy duty mitts, heavy duty crucible, and heavy duty tongs all good suggestions. I wouldn't use high school science lab equipment- 2K degrees is not fun. As palehorse said, metals are really hazardous at those levels. I dabbled a bit with melting some culls about a year ago and it's definitely not as easy as it seems. Check youtube maybe?

JMO wags

Re: melting copper

PostPosted: Fri Oct 14, 2011 6:30 am
by Sheikh_yer_Bu'Tay
Your greatest concern should be safety. How are you going to avoid the dangerous-to-inhale fumes? Do yourself a favor and don't proceed until you can answer that question with certainty.

I have not done this, so I speak only from what I read on the 'net. When you melt "copper pennies", the temp to melt the 95% copper is high enough to vaporize the 5% zinc. Theoretically, once you melt the copper, you have boiled off the zinc. Where does the zinc vapor go? Into your lungs if you are not set up right!! :o :shock:

Look into purifying metals via electroplating and electrowynning instead. There your greatest danger is only electrocuting yourself to death! :mrgreen:

Re: melting copper

PostPosted: Fri Oct 14, 2011 6:31 am
by Sheikh_yer_Bu'Tay
NiBullionCu wrote:take a look here:

http://www.backyardmetalcasting.com/forums/

Hey! Really cool site!! Thanks for the info!!!

Re: melting copper

PostPosted: Fri Oct 14, 2011 6:48 pm
by avidbrandy
Sheikh_yer_Bu'Tay wrote:Your greatest concern should be safety. How are you going to avoid the dangerous-to-inhale fumes? Do yourself a favor and don't proceed until you can answer that question with certainty.

I have not done this, so I speak only from what I read on the 'net. When you melt "copper pennies", the temp to melt the 95% copper is high enough to vaporize the 5% zinc. Theoretically, once you melt the copper, you have boiled off the zinc. Where does the zinc vapor go? Into your lungs if you are not set up right!! :o :shock:

Look into purifying metals via electroplating and electrowynning instead. There your greatest danger is only electrocuting yourself to death! :mrgreen:



Of course none of us melt our copper pennies. but if we wanted to, thank you for this info. I always thought it'd be just a tad suspicious. "I have these lumps of 95% copper and 5% zinc I found that I want to scrap."

Re: melting copper

PostPosted: Fri Oct 14, 2011 6:53 pm
by brexzz1
Is that true? the zinc would vaporize and you would be left with almost pure copper?

Can someone else confirm?

thanks

Re: melting copper

PostPosted: Fri Oct 14, 2011 8:15 pm
by natsb88
brexzz1 wrote:Is that true? the zinc would vaporize and you would be left with almost pure copper?

Can someone else confirm?

thanks

No, you would not be left with pure copper. The metals are alloyed so they will melt together, they won't separate. The alloy will give off zinc fumes, but you won't "burn" off all the zinc. Refining to pure copper would still have to be done electro-chemically, not with heat alone.

Re: melting copper

PostPosted: Fri Oct 14, 2011 9:25 pm
by 68Camaro
Generally just melting it won't drive it all off, as natsb88 says. Some zinc will come off but, as he says, they are chemically connected, and there won't be enough coming off for this to be a method of purification. There can be enough lost, when melting brass, that this caused problems in the middle ages when they melted brass repeatedly - and this was when they didn't know why things worked and didn't work - and they would eventually lose enough of the zinc that the alloy lost properties. So they knew this was a bad thing, but didn't know exactly why, at least for a long time.

Re: melting copper

PostPosted: Sat Oct 15, 2011 2:22 am
by everything
I worked at a foundry once, well I worked in the machine shop part at night while the foundry was shut down :idea:
The last time I brought my stuff in I got more for the catalytic converter I found on the street than anything else. It sure would be great if you could bring your scrap to the scrapyard and trade it for blocks or ingots but nothing is ever the way I want it :roll:

Re: melting copper

PostPosted: Sat Oct 15, 2011 3:55 pm
by Sheikh_yer_Bu'Tay
The melting point of copper is 1,984.32 degrees F. The boiling point of zinc is 1,665.0 deg. F. The vaporization rate of copper is 300.4 kj/mol, while the vaporization rate for zinc is much less at 123.6 kj/mol.

If you raise the temperature of a 95% copper/5% zinc brass alloy to 2000 deg. F.and hold it there, you will start melting the copper within it. You will also definitely start vaporizing zinc.

The purpose of my earlier statements was not about how to purify copper. It was for the purpose of safety. The OP was about IF someone could start melting/refining copper on a budget of $50.00.

What you can do on $50.00 with heating brass alloys is make yourself very sick. And I don't mean temporarily sick. I mean f_cked up for life. Look up what inhaling non-ferrous metal vapors can do to ya. Don't do it.