Adding copper to your alloy using CuSO4

[popper]

I have found that copper can be added to your alloy to give more malleability and/or zinc for hardness to low antimony alloys. Approximately 0.3% Cu and 0.2% Zn can be added to pure Pb, still casts easily (~730F) yet is still a 'soft' alloy. Increasing the Cu to 0.5-2% increases BHN (~38 BHN for 2%) with good malleability, they don't shatter. Heat treating will increase BHN further. The trick is to have equal or more antimony in the alloy. 1% Cu works for 50k psi.
Ok, the HOW-TO.
Use a simple paper painter's mask when doing this. No toxic fumes are released but the powder from the process is bad to inhale. Use the normal protective gear for handling Pb.
This process will replace ALL tin or zinc in your alloy on a 1:1 % basis. The atomic weights of Pb/Sn/Zn are 207/119/65. You can calculate the weights needed but 1/4 US zinc penny/pound of Pb is correct (break them to aid in melting). Tin takes twice as much. I don't use any WW, just use any supposed tin content in them. I cast ~720F so take your alloy up to 750F or so, add Zn (much cheaper) or tin and let it melt. Sprinkle in one tablespoon of CuSO4, Zep root killer is what I use - $12 bottle lasted me 3 years. It is blue and will turn white when the water is cooked off. I lightly push the stuff under the melt to speed the process but watch for the tinsel sprite - you will get some bubbles. You probably will get a blob of crusty 'stuff' on top. Just grind/stir it into your melt. Repeat until the Zep stays white. You're done. Spoon off the powder 'dross' from the top, stir and scrape to get all the powder out and dispose of it. Flux as needed. If you use tin, powder will be grey, zinc makes brownish powder. Both are nasty. I have an old sauce pan for dross, when it cools I add water to keep the dust down, makes dumping easier.
If you want zinc in your alloy, add it after adding Copper. So far, > 0.2% Zn gets tough to cast.
Performance? So far, 'soft' takes the pressure of max 40SW loads (~30k psi), hard works PB to 50k psi (300 BO), GC ~60k psi (308W) with accuracy. I'm testing with BLL so the alloy gets tested. So far I've tested in 9, 40, 30/30 & 300BO, all PB. I'm frugal (cheap) so only use GC for the 308 AR. No complaints. This stuff just plain works. Actually I did try the 'soft' in 30/30 @ 1400 fps GC, results weren't bad so a mushrooming hunting alloy? Still tinkering.

Thanks to R5R for suggesting Cu enhanced when I was having trouble with the 40sw. I sold my welder years ago and don't want to play with tinning speaker wire. Zep just works and is easy/fast/cheap.

EDIQT: my intent here was just instructional as the other threads get a little long.

[Oklahoma Rebel]

have you had a sample tested? that would be interesting to see, I would want to make sure that the zzinc had been replaced all the way, because zinc is the devil, lol thanks for sharing your technique, sounds pretty easy. do you do this in a pot over a burner or an electric pot like a lee?

[runfiverun]

Zinc isn't the devil.
it's kind of hard for me to get, but it is just another metal to use in our hobby.

open your mind to things beyond what's been written or said for the last hundred years.
there are more alloy's than just lead/tin and antimony, many of them are even better for some of our needs.

remember there are many out there that say lead will blow up your gun, or that you can't shoot lead in a rifle, or at high speed without a shotgun barrel attached.

heck I know a guy that has melted strips of plastic into high temperature micro-wax to make a specialty lube.

[Oklahoma Rebel]

yeah, you caught me being narrow minded, I guess it is the whole, get 1/2% zinc in your alloy and all your edges will be round and that kind of information, that truth be told, I learned here. but if I can learn something, I can un learn it. so how much can yyou have in a mix before you get the bad side effects? I probably have 20-30lbs of zinc laying around,WW's, but they would be a last resort thing probably, but I might learn something here in a minute from you!lol thanks, Travis

[runfiverun]

1.5% is safe with tin and antimony. [although you have to use a little higher casting temp]
you just have to remember tin is more attracted to the zinc than the lead or antimony so it forms a different matrix, or just keep the tin amount low enough to act as another grain refiner.
now in plain pure lead you can run 3% zinc as a hardener.
you have a lot of different way's to get there some combinations work well, some need more of less of one thing or the other.

[kbstenberg]

So Popper are you saying cu & zink should be added to a low antimony no tin alloy? And an alloy of .5/2%cu, .2%zn, 2%sb AC will give you an aprox. 38 BHN bullet that is still soft enough to use in hunting loads?
I have to chew on this information for a while.
An there is no illefects to a BP pot.

[runfiverun]

he is saying the no tin thing because you are trading copper in for the zinc.
if you have Tin in the mix it will get pulled out too.

Zinc is used at the reclaim foundry's to strip tin out of lead alloy's.
they water fall sheet the lead and shoot zinc through the melt, it pulls the tin out of the alloy that easily.
he is getting the copper into the alloy with this procedure then adding back in the tin afterwards.

[Oklahoma Rebel]

oh , ok I see why now. makes sense, but is a lot of work to me.

[Reddirt204]

ok armchair caster (still learning, reading etc) by using Cu are you able to reduce the amount of zinc in an alloy?? just thinking about the number of people who have got too much zinc in a blend (missed a couple of wheel weights etc) if copper was added would that help make an un-usable alloy usable again?? Just thinking out loud and I might be way off in the way I am reading Poppers post

cheers

Reddirt204

[popper]

I use a Lee BP pot, no problems. 38 BHN alloy is not going to be soft. Normally I use 3% Sb/0.5% Cu. I have gone to 3% Sb/2% Cu - really hard (rifle). I tried 0% Sb/0.3% Cu - really soft (pistol). I have some rifle alloy that is 0.5%Cu/0.2% Zn I want to try, unfortunately I coated with BLL and got too hot trying to 'cure' the BLL so they got softer. Haven't shot them yet. I've found that Cu really improves the 'quality' of the alloy, CuSO4 & Zinc are cheap - like me - so I don't need to buy hardball or #2 or lino to get the performance I want. The process to add them is simple. A side goal is to make a cheap alloy that works with HiTek/PC (for HV rifle) that works without WD.
I won't post more in this thread as I wanted to make it a How To. thread.

[bkbville]

Thanks Popper - I've been getting lost in many of the long threads - it's good to have a summary than try to make sense of 50 or 60 pages!

[Oklahoma Rebel]

who's armchaircaster?

[Oklahoma Rebel]

oh ok nvm, in the first post you added a tablespoon to your alloy, but how many pounds was that, if you could say, a tablespoon to ten or whatever lbs will make such and such percentage, it would help a lot of people I imagine, and what % cu is that zep stuff?

[Reddirt204]

who's armchaircaster?

I meant to say I am an armchair caster at the moment...

still trying to learn all I can before I am in a position to start melting lead

Although it might be a good handle for someone

cheers

Reddirt204

[Oklahoma Rebel]

lol, this is a good place to learn, welcome and goodluck

[popper]

Added 1 penny weight of Zn to 5# pure, then sulfated. Added ~ 2 tbsp sulfate (a little at a time) then done. Some white sulphate left on top. Pound test, as mallable as pure, little harder.I'll cast some shootable, then add a tich of Zn and try those too.

[uncle dino]

Does this copper/zinc alloy age harden like other alloys? Or is it stable like lead/tin. D

[popper]

The Pb/Sb/Cu age hardens and WD hardens. No history on my ? metal, it WD hardens a bit. The Pb/Cu/Zn tinkering is in another thread - just to keep it out of the Cu thread.

[uncle dino]

Thanks popper ..just looking for a stable harder alloy suitable for swaging ...lead:tin gets spendy. I don't want my cores age hardening...d

[meeesterpaul]

I have a lot of hard letterpress types. I have it separated by XRF scan results. Some of it has Cu in it. I could make up ingots of different alloys to order using bumpo's very helpful spreadsheet.