Copper sulfate

[F_L]

I need some help hardening lead with copper sulfate. I've read the sticky, searched a bunch of posts but still having trouble. The alloy I have used for years is 2.5 Sb, 2.5 Sn. Very similar to WW + tin, tests to 12 BHN. Age hardens to 13-14 BHN. It has worked fine for years but I recently started casting HP. The feed ramp on my semis is deforming the nose, affecting accuracy. I think the copper hardening would be the perfect solution.
I tried Popper's copper sulfate method. Heated the lead to 750+, layer on the copper sulfate, cook the moisture out, break up the crust, stir back into the melt, flux is into the melt, stir some more..... Resulting ingots test at 10 BHN. I let is age a couple of days and no change. I repeated the procedure and dumped the dross from the first try on top. Added some more copper sulfate and result is still 10 BHN.
Anyone have any ideas?

[Dusty Bannister]

Adding copper yet removing tin and antimony with copper sulfate does not seem like a positive method of trying to harden an alloy. Also testing ingots rather than the cast bullet itself leads to error. Try again with the flat nosed bullet instead of an ingot, and keep in mind low antimony alloy content takes longer to age harden. Try testing after a couple of weeks, not a couple of days.

[762sultan]

I only used copper sulfate to remove zinc and the results were that the lead had joined with the zinc and the copper sulfate to make the final product malleable and removed most of the zinc. Don't know if it made the alloy harder or not but I took a bullet and hammered it on an anvil until it was flat and it did not split.

[BK7saum]

i would think you would be decreasing your hardness. The copper sulfate removes Sb and Sn and replaces it with Cu. Cu itself adds toughness, not hardness. The Sb provides more hardness than Sn or Cu.

[F_L]

Maybe I'm all screwed up but thought the copper replaced the tin. Popper showed some pretty impressive gains in BHN with small (.2-.3%) amounts of copper. I need to dig back into it.

Thanks!

[BK7saum]

i may be wrong, never done it myself. i think once copper was added by removal (replacement) of alloy components then antimony and tin needed to be re-added to the alloy.

If i wanted to add Copper, i would try to add copper by the other reported method. I would tin some very fine speaker wire and allow it to dissolve into the alloy i already have.

[bangerjim]

CuSO4 removes Zn...........................and also Sb and Sn!!!!!!! Not something you really want to do.

Cu adds "toughness" to an alloy, but not that much hardness. Stick to good old Sb for that hardness gain. If Cu was that magic hardness-adding ingredient, you would find it in COWW's and other alloys on a regular basis........and not Sb, which is more expensive than Cu.

Best way to add Cu to your alloy is find a know alloy of Babbitt that is rich with Cu ( they vary all over the map) and add that.

You can try dissolving tiny amounts of Cu in your mix, but I have never had any luck with that method. I stick to Babbitt.

[popper]

Copper will replace Zn and Sn, NOT Sb. Small amount of Cu will increase malleability and not much hardness. 0.3 to 0.5% should be fine for hunting. 2% will get to to solid coppers (dents a bar of superhard). You need to let it 'cook' in the pot for and hour or so, stirring well to get all the Cu attached to the Sb. Then skim the trash off the top, it should just be a very fine powder (don't breathe it - powder will be brown or grey, depending on Zn or Sn replaced)). When you get all the powder to the top (and it takes a lot of scraping/stirring), alloy should look VERY shiny and CLEAN, NO dross! Less than 1% Sb it doesn't do much of anything. Normal Babbitt is mostly tin and diluted to get the tin down to proper %, almost NO copper. I don't use HP and suspect it won't prevent bending a nose. The nose just won't frag when it hits something. I don't use a BHN tester so can't give any help there but Cu does help the bullet. I did a texas heart shot on 150# hog, broke front leg, took out the lower jaw and never recovered the bullet (40sw 165gr PCd, 20 yds). Posted same load shot into rock pile from 5 ft, almost 100% retained wt. TC became a cylinder.

[F_L]

Copper will replace Zn and Sn, NOT Sb. Small amount of Cu will increase malleability and not much hardness. 0.3 to 0.5% should be fine for hunting. 2% will get to to solid coppers (dents a bar of superhard). You need to let it 'cook' in the pot for and hour or so, stirring well to get all the Cu attached to the Sb. Then skim the trash off the top, it should just be a very fine powder (don't breathe it - powder will be brown or grey, depending on Zn or Sn replaced)). When you get all the powder to the top (and it takes a lot of scraping/stirring), alloy should look VERY shiny and CLEAN, NO dross! Less than 1% Sb it doesn't do much of anything. Normal Babbitt is mostly tin and diluted to get the tin down to proper %, almost NO copper. I don't use HP and suspect it won't prevent bending a nose. The nose just won't frag when it hits something. I don't use a BHN tester so can't give any help there but Cu does help the bullet. I did a texas heart shot on 150# hog, broke front leg, took out the lower jaw and never recovered the bullet (40sw 165gr PCd, 20 yds). Posted same load shot into rock pile from 5 ft, almost 100% retained wt. TC became a cylinder.

Thanks! I was hoping you would post here. Apparently I didn't cook it long enough. I'll try again and post results.

[bangerjim]

Copper will replace Zn and Sn, NOT Sb. Small amount of Cu will increase malleability and not much hardness. 0.3 to 0.5% should be fine for hunting. 2% will get to to solid coppers (dents a bar of superhard). You need to let it 'cook' in the pot for and hour or so, stirring well to get all the Cu attached to the Sb. Then skim the trash off the top, it should just be a very fine powder (don't breathe it - powder will be brown or grey, depending on Zn or Sn replaced)). When you get all the powder to the top (and it takes a lot of scraping/stirring), alloy should look VERY shiny and CLEAN, NO dross! Less than 1% Sb it doesn't do much of anything. Normal Babbitt is mostly tin and diluted to get the tin down to proper %, almost NO copper. I don't use HP and suspect it won't prevent bending a nose. The nose just won't frag when it hits something. I don't use a BHN tester so can't give any help there but Cu does help the bullet. I did a texas heart shot on 150# hog, broke front leg, took out the lower jaw and never recovered the bullet (40sw 165gr PCd, 20 yds). Posted same load shot into rock pile from 5 ft, almost 100% retained wt. TC became a cylinder.

There are at least 5 alloys called "Babbitt" that range from 2.5 to 8.5% Cu content. I have 3 of them and use for adding Cu when needed.

For info go to:

https://en.wikipedia.org/wiki/Babbitt_%28alloy%29

[F_L]

I want to thank Popper for the tips. Following his instructions I managed to get some Cu in a few ingots that test to 14 BHN. That's up a couple of points from my normal 2.5 Sb, 2.5 Sn alloy. I'm sure I could have gotten more Cu in the mix but will experiment with this first. It will be interesting to see what it age hardens to.

[popper]

I am not a chemist or metallurgist but from what I have learned:
Lead is malleable, changes shape without 'breaking'.
Antimony has a higher melt temp and 'tends' to cool and 'coat' the outside of the bullet as it cools. It also tends to glob up so is not evenly distributed in the lead.
Lead is a crystal structure and it's 'malleability' comes from a chunk 'sliding' along a shear plane. Our 'hardeners' roughen the shear plane so it doesn't 'slide' so well.
Now Sb & Cu form a large molecule, thus a large spot in the plane and more force is required to cause the slip. Globs of hard Sb are not formed, so shattering of a harder alloy doesn't occur.
It gets hard faster, as observed when sizing. WD and it gets hard faster, like a higher Sb alloy. My 2% Cu 4% Sb 0% Sn when vice tested with a ingot (rotometal bar) of superhard made a bigger dent in the superhard.
Brinell and Rockwell testers punch a small dent in the metal and measure deformation. There is a fancy machine that actually generates a real stress/deformation curve, BHN is just a standardized testing method. It is NOT very good for malleable metals.
Not going to get into any real technical explanation of it. So Cu 'toughens' the cast bullet and it can 'measure higher BHN.

[RickinTN]

If you wanted to harden the alloy why not simply water drop it from the mold. Your alloy has plenty of Sb to do the trick. I may be wrong but I think you could expect a hardness upwards of 20 after a week or so. I'm sure others with more experience in the matter will chime in, in fact I'm surprised they haven't already as I think it's the easiest method to produce your wanted results.
Rick

[bangerjim]

Many on here PC their boolits and any hardness created by old school water dropping is mostly wiped out by the 10-15 minute soak in the curing oven at 400F.

So I would not bother dropping..............if you plan on PC'ing. And 400 F is not hot enough to get the hardening effects you are talking about with mold dropping.

I just mix my alloys (Pb + Sn + Sb [+ Cu if wanted]) to the air cooled hardness I want and then PC. Life is simple and very repeatable that way.

[farmbif]

the only place I use copper sulphate is to control fungus and leaf curl and stuff like that on fruit trees and on some row crops. its not very nice stuff to deal with, I could never imagine putting it in pot of molten lead

[F_L]

Thanks to everyone that commented. This has been a fun, informative project. I may have some babbitt in my future but copper sulfate is cheap and readily available. Dusty mentioned the difference between testing hardness of ingots and bullets. I cast a handful 220 gr FP boolits with my Sb2.5, Sn2.5 alloy and the copper enhanced alloy. I then water quenched half of each batch after powder coating. I'll check them for hardness for the next couple of weeks. My goal is to find out hard a boolit needs to be to get acceptable accuracy (2-3 moa) out of a semi-auto. I can still single load a softer alloy, follow with a mag of the harder stuff. Most hunting is a one shot deal. Maybe a final shot on a downed animal.

I did a test on water quenching the 2.5, 2.5 alloy a while back. I heated some previously powder coated boolits to 450 for 30 min then water quenched them. The result was BHN 20. The boolits shattered during the hammer test but Smoke's powder held up fine. I am hoping the copper or experimenting with lower heat treating temps will solve that.

[popper]

I heat soak 400F for an hour (really just cook the PC coated for and hour), then drop in ICE water. Arsenic will speed up the hardening. I don't use any tin. My AR10 308W gets MOA @ 200 (168gr GC) 2400 fps. The 24" barrel gets 2700 and same accuracy @ 100.

[bangerjim]

the only place I use copper sulphate is to control fungus and leaf curl and stuff like that on fruit trees and on some row crops. its not very nice stuff to deal with, I could never imagine putting it in pot of molten lead

All it does is turn from blue to white, telling all the moisture has been rendered out. Not dangerous at all. It is an excellent root killer!

[popper]

My pistol alloy is 2% Sb/0.5% Cu. Rifle is a little higher Sb. Shot 165gr (950fps) 40sw @ 25 yds tail shot 150# hog. Broke front leg and lower jaw, bullet kept going. Shot dead pig with 1% tin, 30/30 point blank in gut, pass through. Same pig/load in shoulder - NO exit. Choose what you need.