Copper Ingots from Copper Tubing and Fittings

Afternoon,

I am a long-time commercial heating, ventilation and air conditioning contractor by trade and a newby refiner by hobby. (I already deal in scrap gold and silver and silver coinage) I come across better than 100lbs of clean copper tubing and fittings per month (free scrap) that I would like to melt into copper ingots for resale. (mostly for fun, but the scrap yards around us are well below spot for #1 copper scrap anyway and I shouldn't be giving money away like that!)

(I also come across a lot of bronze and brass, but that's a story for another day)

In looking at the MSDS, typical copper tubing and fittings are already 99.9% pure Cu. I have a KerrLab electro maxi-melt unit. Can anyone help me with a process to basically re-melt and re-form the copper into ingot molds? Do I need to anticipate any polishing process afterwards? Am I over simplifying this? I really haven't seen much on the subject.

By the way, being in my trade, I have access to all kinds of ventilation equipment, motors, electrical parts etc and I would be happy to pass along at trade wholesale cost, without any markup, to the members of this forum...

Thank you kindly for your comments and assistance.

Don
[email protected]

It surprises me that you are being shortchanged on the really clean scrap copper. Are you aware that copper has taken a MASSIVE price dump (from $4.2x to right about $3.00 even, now back to about $3.55) or are you saying that regardless of spot price, your local scrappers try to skin you?

It also surprises me that people buy copper ingots on ebay, it seems silly. I admit, I have seen them being sold. I don't understand the compulsion, I guess. The guy(s) who sell them take bus bar and band-saw off a a chunk. Then they stamp them ".999". There's no assay being carried out, it's a sham. Yes, we all know that standard copper is very pure, even remarkably so, but what's the attraction in owning it? If it's so great to own then why can't a buyer go to a metals supplier and order bars of copper say 3" x 10" x 1/2" thick? I don't get it.

But I can tell you that after you (purchase the fuel and ingot molds to) heat up your copper and scrape off (eg; lose) the dross from the melt and polish the bars and pay listing fees and paypal fees on ebay, it would (again) surprise me (I am easily surprised, I guess) if you could do better than just scrapping your metal, just by waiting for a better market price. I guess in the end it depends upon how much people are willing to pay you for nice shiny bars.

Ebay plus paypal have become fairly punitive. Together, they take about 12% of a sale. How does that impact your math?

Incidentally, if you are still curious about melting and ingotizing copper, there are some number of YouTube videos that show guys doing this. Search "copper" "pour" "ingot" "melting" in various combinations.

Element47,

I had no idea that eBay plus Paypal fees equaled 12% these days!

Even if I don't sell them on eBay, I'll still enjoy playing around with it. I could stock pile hundreds of pounds as well, or even give them away as Christmas gifts to family and friends... J/K I could, however, have custom ingot molds made and then give the bars away to customers as a promotional advertisement. (Hmmmm I think I might have an idea there)

Thank you for the YouTube idea, I will check it out!

Regards,

Don

Watched 100lbs. of .999 CU bars go for $7.00 per lb. on ebay. I know what you mean about scrap yards, they pay what they are willing to pay and that's it. A 10lb. .999 CU bar is still just #1 copper at the local yards, and they won't even give you bare bright for it. I won't sell to them any more, only take my sheet steel there. Hell they won't even pay you for stainless if it sticks to a magnet, they want to pay you at ferrous price. You try to tell them that they are not consistent with ISRI Code and they look at you like wow how the hell do you know about that.

Melting clean copper wire or pipe into an ingot will destroy the hallmark. What????
Yep, when the scrap yard buys copper pipe or wire they know what alloy they are buying. If you melt it into an ingot they will give you less money for it because they don’t know what the alloy is at this point because you have taken a pure product and melted it into god knows what. It takes more money to seperate the materials at this point so they charge you for it.

If you're never melted copper, I suggest you give your idea considerable thought before you make an attempt.

Copper is not user friendly. It comes out butt ugly---although dumping the still red hot ingot from the mold and then dumping in cold water goes a long ways towards eliminating the oxide coating that makes it so damned ugly. It must be poured at about 2,000° F---which is not comfortable without safety gear.

How do you propose to melt the stuff you have? It will have considerable oxide (that's the nature of old copper) so will require at least a little fluxing. That's tough on crucible life, and crucibles aren't cheap. You can't melt in a metallic vessel---at least not if you're in your right mind. It would get dissolved by the molten copper quite rapidly, and contaminate the copper, so you've defeated the purpose in melting. You'll have turned a known product in to an unknown product, drastically reducing its potential value.

All in all, I say your plan isn't a good one. The small amount of profit you may realize from melting, assuming you do everything right and enjoy success, will have long since been eaten up by the time you'll invest in the project. Do it only if you want the experience of doing ------you aren't going to make money.

Harold

can you use the red clay or porcelain flower pots that have no hole as a one shot crucible?

Red clay pots are among the the lowest firing temperature clay family. They fuse together poorly making them brittle. A large portion of their make up is iron oxide. They may just melt at high temperature or simply break unexpectedly. I certainly wouldn't attempt it.

Harold_V said:

If you're never melted copper, I suggest you give your idea considerable thought before you make an attempt.

Copper is not user friendly. It comes out butt ugly---although dumping the still red hot ingot from the mold and then dumping in cold water goes a long ways towards eliminating the oxide coating that makes it so damned ugly. It must be poured at about 2,000° F---which is not comfortable without safety gear.

How do you propose to melt the stuff you have? It will have considerable oxide (that's the nature of old copper) so will require at least a little fluxing. That's tough on crucible life, and crucibles aren't cheap.

All in all, I say your plan isn't a good one. Do it only if you want the experience of doing ------you aren't going to make money.

Harold

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Harold,

Great tips and information, thank you very much...!

The clean #1 copper we get from installation tear-outs and left over pieces from new installations is basically "free." TThe scrap yards around here are $1.00 a lb under spot value, but the profit motive isn't my only motivation with the copper end. I do look forward to playing around with it for fun as I get my feet wet- starting with small batches under 1 lb... I was thinking of pouring some ingots into a custom mold with our company logo and phone number on it and giving them away to customers as a promotion. (Thanks to Smack, for inspiring me with this idea)

I have a Kerr 100 troy ounce (gold) electro-melt maxi furnace that I got for gold and silver refining. Top temperature for the unit is 2050 degrees F. (Maybe this isn't the right unit for melting small batches of copper, due to the upper limit of only 2050 degrees F. and the fact that I don't want to burn out too many heating elements!). I do have various acetylene torches for sheet metal fabrication and welding as well as soldering and brazing, and plenty of safety gear, so I could get a few proper crucibles. Smack gave me a web address for a vendor that sells crucibles.

I understand I will need to use non-metallic crucibles and flux and only use one crucible per type of metal being melted.

Will buffing or polishing after immersion in cold water help to make the "butt-ugliness" go away?

Have a great day!

Don

HigginsMechanical said:

I do look forward to playing around with it for fun as I get my feet wet- starting with small batches under 1 lb... I was thinking of pouring some ingots into a custom mold with our company logo and phone number on it and giving them away to customers as a promotion.

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That's not a bad idea, but I think you'd be well served to do a touch of alloying. Phosphorus can be added to improve the molten material, with no alteration of the end product color. It can be acquired from dealers that market non-ferrous metals for the casting industry. It comes alloyed with copper, so all that is required is to add a specific amount to each heat.

I have a Kerr 100 troy ounce (gold) electro-melt maxi furnace that I got for gold and silver refining. Top temperature for the unit is 2050 degrees F. (Maybe this isn't the right unit for melting small batches of copper, due to the upper limit of only 2050 degrees F. and the fact that I don't want to burn out too many heating elements!). I do have various acetylene torches for sheet metal fabrication and welding as well as soldering and brazing, and plenty of safety gear, so I could get a few proper crucibles.

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The problem you'll experience with a furnace of that type is the short lifespan of the crucibles (they are machined from graphite, and burn away as they are used), plus they are slow to heat. They are costly in the scheme of things. A bilge type crucible, graphite/clay, or silicon carbide, is a better choice, although that requires that you have a furnace.

Both GSP and I have experienced those electric furnaces. Neither of us care for them and would have recommended you avoid the purchase. You can build a small crucible furnace that operates on natural gas, propane or fuel oil for less than you paid for the Kerr, assuming you didn't get one hell of a deal.

In regards to refining, you can get by admirably with a torch and melting dishes. Rarely will you ever have the volume that can justify a melting furnace, although that may not be true with silver.

I understand I will need to use non-metallic crucibles and flux and only use one crucible per type of metal being melted.

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Flux can be your enemy. When casting, it should not be allowed to pour with the charge, so skimming is required, or you can buy and use bottom pour crucibles. In any case, flux will shorten the useful life of all types of crucibles, so it should be used with judgment. Some metals allow for flux free casting. Clean copper can be one of them, assuming you inoculate with phosphorus.

Will buffing or polishing after immersion in cold water help to make the "butt-ugliness" go away?

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It's not as bad as I made it sound, depending on what you expect as the outcome. Simply plunging the still red hot ingot in water will improve its appearance considerably, then you can use the time proven process of pickling the casting(s) in dilute sulfuric acid. It doesn't dissolve copper, but dissolves copper oxide with a vengeance. That will improve the appearance considerably, but it will still look like a casting. Problem is, nice, clean copper doesn't retain the surface appearance. It's quick to dull. You'd have to do a little exploring to see if you're happy with the outcome-----and have the option to coat the pickled ingots with clear lacquer.

Give a little thought to building a proper melting furnace if you're going to mess with this stuff. It's a great project, if nothing else.

Harold

Harold,

I sincerely appreciate you sharing your experience and wisdom and your advice is duly noted Sir...

Thank you,

Don

I have enjoyed some success melting copper ingots.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=45&t=11946

I used old, left over copper wire from cementing silver (there may be some silver in these bars)

They are black when they come out of the mold.

Thrown into a bucket of cold water removes some of the blackness.

I actually pickled the bars in dilute sulfuric. The black turns to red and the red rinses right off under a flow of hot tap water.

I plan to use these ingot (weight is about 150 grams each) for cementing silver.

kadriver

Polished up a couple brass bars. Hard to get a smooth pour and bar from brass, going to try a stream of Argon/Co2 to keep oxygen out. Maybe I'll put this one on ebay.

Hello all , how are tricks?
I hope all is well!

Smack said:

Polished up a couple brass bars. Hard to get a smooth pour and bar from brass, going to try a stream of Argon/Co2 to keep oxygen out. Maybe I'll put this one on ebay.

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Smack , that looks lovely , nice work chief!
Let us know if you do decide to place one on ebay , it would be interesting to watch and see where they go!
Just out of curiosity , what are the weights on these as they look nice and weighty ?
All the best and kind regards ,
Chris :mrgreen:

That one is 7 lbs. or just over 3 kilo.

Smack said:

That one is 7 lbs. or just over 3 kilo.

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That is nice and weighty , thanks for the reply chief!
All the best for now , and kind regards ,
Chris :mrgreen:

That is a nice hunk of brass, I think I would try and change the shape a little, if I went to the trouble to melt and pour then polish, like make a useful object out of it in a casting mold, vacuum educator, bell, mini micky mouse, horse statue, or some other object of use or decoration.

I've got 16 of them so far.

How are you making them nice please share

please let us know what furnace your using