Alloying Copper into Lead

[303Guy]

How does one alloy copper into lead?

The idea is to toughen the supposedly almost pure lead with I think about 1% copper to toughen it without hardening it too much.

[357maximum]

The best way I know how to add copper to the mix is with a bearing babbit that contains copper.

I did manage to melt some fine copper phone wire directly into the mix but I had a rough go of it. I used a rosebud tipped oxy/acetylene torch, a turkey friar and a mapgas torch all at the same time. I am sure the temp was up there waaay beyond where one should take lead (the whole melt was cherry red) and the mix would only take so much copper....and I had to have a big fluxing fire the next time I melted it. Not real sure if I actually got much % into the mix.

I scrapped that plan and went to railroad bearing babbit which gave me tin and nickel also.


Maybe someone with actual knowledge will come along and explain my miserable results.

[sagacious]

Copper is not very miscible in lead. I don't think you'll be able to get 1% copper in solution in pure lead (yes, I have tried). This is why pure lead does not work well as a solder for copper. One needs some Sn in the solder to wet copper. This is a critical clue.

Strengthening lead is not really a mystery. A few percent Sn will strengthen lead without increasing brittleness. 1% Sb can increase the strength of Pb by 50%, and without increasing brittleness too much. Going to copper to "toughen" lead is going the hard route when easier solutions exist, and the Cu route is not as straightforward as it seems.

To get any meaningful copper in solution, you'll need to add Sn and/or Sb to the alloy. The copper forms a soluble intermetallic with the Sn or Sb, but only as a low % Cu. Any more than a few percent will rise to the top somewhat like antimony crystals do, and drossing is heavy. If you're going to add Sn or Sb as a route to adding Cu, well, I reckon it seems that you've already solved the "toughness" aspect without adding the Cu.

357Maximum's posted experience and conclusions are spot-on accurate. You can heat lead + copper until it is red hot, but the two slide around like oil on water, as almost none of the copper will dissolve even at red heat. Good luck.

[StarMetal]

Since lead is practically insoluble in copper, a cast copper-lead microstructure consists of lead pockets in a copper matrix. These pockets of lead serve as reservoirs for maintaining a continuous lead film on the bearing surface.

[riverwalker76]

I've melted copper and molded it on several occasions. It's not easy to do!

On one occasion I placed a mold inside a steel pot with a copper ingot sitting over the mold. When I got the copper hot enough it started to flow into the mold and it was around 1500 degrees fahrenheit using a laser heat thermometer. I had to start a wood fire using a 3 gallon bucket of lard, and used a leaf blower as a billow. :redneck:

After that ordeal I invested in a 40 amp pottery kiln and digital controller. I can now melt copper in an hour or so since my kiln reaches 2200 degrees fahrenheit before it hits it's heat threshold.

[303Guy]

Mmmm... Thanks. This is pretty much what I suspected. I know that copper dissolves into high tin solder so I thought a tin/copper alloy might be required. Pretty much like dissolving iron in aluminum. One buys a high iron alloying mix made under special conditions. Well OK, I'll go with the tin option for now (lead pipe with soldered joints). I'm not sure where to get babbit metal. I'll ask my lead pipe supplyer when I go there next.

[lwknight]

I asked about babbit metal from a few suppliers and went away with my tail between my legs so to speak.
Some of the tinn/copper babbit was like $25.00 per pound. Which may seem cheap in the future as the US dollars false props begin to fall out from under it and China owns everything
.

[357maximum]

I asked about babbit metal from a few suppliers and went away with my tail between my legs so to speak.
Some of the tinn/copper babbit was like $25.00 per pound. Which may seem cheap in the future as the US dollars false props begin to fall out from under it and China owns everything
.

I only add 5% of the precious babbit to a mix of ww/pure 50/50 and it serves it's purpose real well. I run some of my cast a bit stiff by normal standards and the toughness works in concert with the mallability of the 50/50 for a very tough yet mallable boolit that can be DRIVEN accurately and not cause fear of shattering or shearing when it hits a critter. I have a pic here somewhere of a BRP-360-220 that was shot into sand with a 2800 launch speed....i will see if I can find it. I did not want my boolit to SPLODE on closer shots, but I still wanted some shroomin at longer distances....I like the way it worked out.....SPEED is worthless without accuracy and total confidence in your casting when it actually comes to crunch time.

*** I know I ain't got to go fast with cast to kill, but a little flatter trajectory is not always a bad thing***:wink:

[nicholst55]

Some of the tinn/copper babbit was like $25.00 per pound.

Board sponsor Rotometals has 'Copper Hard Babbit,' containing 0.5-1.5% copper, for $7.50 per pound.

http://www.rotometals.com/Babbit-Bearing-Alloys-s/2.htm

[markinalpine]

Board sponsor Rotometals has 'Copper Hard Babbit,' containing 0.5-1.5% copper, for $7.50 per pound.

http://www.rotometals.com/Babbit-Bearing-Alloys-s/2.htm

Beat me to it!

So how the hell is Camp Casey, anyway?
I was in the DISCOM 1978-1979. Hated the damn place.

Mark :[smilie=s:

[303Guy]

Thanks for that 357maximum. That's exactly the info I was looking for!

I see one can get copper rich solder too (no idea where though). The curious thing is adding copper to lead/tin alloy lowers the melting point! Adding lead to tin/copper alloy reduces the solubility of copper in tin. Complicated stuff this.:veryconfu