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Zeb Camper

copper smelt gone wrong

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Decided I would weld up a steel cup and melt some copper down in my really nice forge. I used my stick welder with some 6011 electrodes. Didn't chip the slag between passes, must've been a pin hole, melted into the forge. Anyone got any Idea as to how I should remove the copper? It seems pretty stuck. I'll probably just have to buy new wool, and ceramic. 

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A picture would probably help, but chances are chipping it out is going to be the best bet.  

Also, this is copper melting.  Smelting is a conversion from ore to metal.  And steel is generally a bad crucible for copper, they react.  Get yourself a refractory or graphite one (or make your own).  

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Steel is generally bad as crucible, except for low temperature metals like tin. Iron dissolves in liquid copper in the same way that sugar dissolves in water. I'd save the trouble of making crucibles, and buy a professional one. I use silicon graphite crucible, they're practically care free, provided that you don't get them excessively hot (>1300C). 

To get the copper out, you may try simply by heating the forge, and see if you can scrape it out when it's at near melting point. 

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4 hours ago, Jerrod Miller said:

A picture would probably help, but chances are chipping it out is going to be the best bet.  

Also, this is copper melting.  Smelting is a conversion from ore to metal.  And steel is generally a bad crucible for copper, they react.  Get yourself a refractory or graphite one (or make your own).  

Hi Jerrod and Jerroen, thanks for the information. I am totally new to the MELTING game. I had a bunch of scrap copper, so I figured I might as well give it a try. I spent the rest of the day working on my truck to let the forge cool. luckaly I think most of it formed a long beed in a crack, I was able to get that beed out. I hope none of it seeped further down. I will head to my shop later to see what the rest of the damage is if there is any. Thanks again for the Info, will definatly buy a crucible, and use my harder to ruin coal forge!

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You can see where this was stuck on the side wall. The bottom brick Is broken now. I tried chipping it. But, luckally chile sells that brick as a "sacraficial" piece to save the real forge floor when forge welding. It's a $45 fix. 

20170818_172308.jpg

20170818_172222.jpg

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1 hour ago, Zebulon Camper said:

Hi Jerrod and Jerroen, thanks for the information. I am totally new to the MELTING game. I had a bunch of scrap copper, so I figured I might as well give it a try. I spent the rest of the day working on my truck to let the forge cool. luckaly I think most of it formed a long beed in a crack, I was able to get that beed out. I hope none of it seeped further down. I will head to my shop later to see what the rest of the damage is if there is any. Thanks again for the Info, will definatly buy a crucible, and use my harder to ruin coal forge!

A coal forge is not suitable. You need furnace, rather then a forge. And coal gets far too hot and too concentrated. It may melt your copper, but your crucible will not like it very much. A furnace ensures an even temperature all around the crucible, particularly at the top opening, which should be kept at around 1200C. If you overheat the copper, it will absorb large quantities of oxygen and other gasses, and you get a bubbly casting. Casting pure copper is very difficult for that reason, particularly if you want to shape it further after casting, either by cold working or machining. Getting a good casting with copper without internal cavities is not easy. Bronze is a lot easier (relatively, still a challenge), if you add some tin. About 3-4 % still still gives a red coppery color, though a bit lighter and more pink, but is already significantly easier to cast. 

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19 minutes ago, Jeroen Zuiderwijk said:

A coal forge is not suitable. You need furnace, rather then a forge. And coal gets far too hot and too concentrated. It may melt your copper, but your crucible will not like it very much. A furnace ensures an even temperature all around the crucible, particularly at the top opening, which should be kept at around 1200C. If you overheat the copper, it will absorb large quantities of oxygen and other gasses, and you get a bubbly casting. Casting pure copper is very difficult for that reason, particularly if you want to shape it further after casting, either by cold working or machining. Getting a good casting with copper without internal cavities is not easy. Bronze is a lot easier (relatively, still a challenge), if you add some tin. About 3-4 % still still gives a red coppery color, though a bit lighter and more pink, but is already significantly easier to cast. 

Interestingly enough, I got one successful casting of a smaller amount before i added that plus the rest of my copper into the second cast-tastraphe. I'll look for a picture if I took one. But would the propane forge be suitable if it's all you had? Also should I expect my copper to be ruined now? I read of a company that uses iron as an alloy in copper to refine the grain structure of copper alloys. Could this copper be used in adition with something like nickel for a usable billet? The interweb isn't giving me much info, but I'm curiouse now. 

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24 minutes ago, Zebulon Camper said:

Interestingly enough, I got one successful casting of a smaller amount before i added that plus the rest of my copper into the second cast-tastraphe. I'll look for a picture if I took one. But would the propane forge be suitable if it's all you had? Also should I expect my copper to be ruined now? I read of a company that uses iron as an alloy in copper to refine the grain structure of copper alloys. Could this copper be used in adition with something like nickel for a usable billet? The interweb isn't giving me much info, but I'm curiouse now. 

A propane forge is a lot better, as it gives a better heat distribution all around, and better temperature control. Best also to add a piece of charcoal in the crucible to get rid of oxygen that might otherwise enter the copper.

The copper should probably be fine for reuse. I don't think some iron in it will give much problems, at least not that I'm aware of. 

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To get that off, use a torch to melt the copper and allow it to roll off.
The rest of what everyone says is true, you need a proper crucible.
You can use a solid fuel forge to smelt in but its tough.
You should also put a small bit of charcoal in the crucible.
Copper is real oxygen sensitive.

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