radiator solder

[barsik]

I have managed to scrounge a few hundred pounds of floor sweepings out of a rad repair shop and I wonder if antimony can be added to the solder to increase the hardness. the clean ingots are very soft , probably little different from pure lead. due to the fact that each radiator probably had a different solder used during manufacture the lead/tin ratio would be impossible to predict. should I just treat this alloy as pure lead and do a 94 lb solder and add 6 lbs of antimony to get a decent alloy? I'm also assuming the high tin content won't hurt my barrel. if anybody has any advice I'm all ears. thank you in advance.

[Dom]

A BHN tester could be helpful to determine the actual hardness of the alloy you have. This way you could better know the amount of lead , + OR - to add. . Just a thought

[uscra112]

That solder could be tin-rich. Test it. If it is, it'd be a horrible waste of expensive tin to cast with it as-is. Pure lead melts at about 620 F. - if your metal melts much below that, it's high tin, and should be used to alloy pure lead.

95/5 lead-tin melts at about 580 F.
50/50 is more like 400 F

[BK7saum]

I would expect the solder to be 40-60% tin. I would not use it as the base alloy, but as sweetener for other alloys needing tin.

You can cast a bullet with the solder and one with pure and get an approximation of tin content.

[hc18flyer]

A fellow forum member 'BNE' can test it for you. Give you a much better idea. Tin is the most valuable component needed for bullet casting. Once you know what you have, other forum members be happy to trade you lead or wheelvweights for it. hc18flyer

[Rapier]

Just a bit of help, 10 pounds of tin and 90 pounds of pure lead, makes a 10% alloy. Right now you are at roughly 50/50 solder, to make it easy. If you use a net 100 pounds weight you can add to the rest of a general alloy to make 100 pounds and get an easy rough percentage. A bit to think about;

Clip on wheel weights are roughly 96% lead, 5.17% Antimony, .5 % Tin and .05 % Arsenic. With 50 % tin solder you have a long ways to go to get to .5% just for adding pure lead.

Just as an example: The 70/20/10 alloy, WW, Lino, Chilled Lead Shot is roughly
93.5 % Lead, 5.17 % Antimony, 1.14 % Tin, .13 % Arsenic This indicates you can use your 50/50 solder to make hundreds of pounds of bullets with enough pure lead and a bit of antimony. The alloying with pure Arsenic is iffy at best, to fool with. The reason for using chilled lead shot, is it is alloyed with Arsenic to start with. There is a ton of difference between .05 and .13%, like near 3x as much.
Pay close attention to the alloying temperature required, odd situation is that it may take 1200 degrees to alloy but only 600 degrees to melt after alloying.
If you use 91pounds of lead, 4 pounds of 50/50 solder, 5 pounds of antimony, you will have a rough 93% lead, 2 % tin and 5 % antimony. It will be a long, long time use of 50/50 solder.

If you want to add surface hardness, try water dropping the hot bullets right out of the mould. 5 gal bucket covered by a thin layer of wet styrofoam peanuts, stops water splashing.Might save on antimony use.

[JonB_in_Glencoe]

Look up the Tin/Lead melt temps for various percentages. Then find the melt temp of your alloy. It's likely 50-50, as that's the traditional radiator solder alloy. Then add pure lead and antimony for a desired boolit alloy.

[lightman]

I would cast it all into ingots and have BNE test one of them. That way you know exactly what you have and can use it to the best advantage. Oh by the way, Nice Score!

[Dusty Bannister]

From time to time, I see unusual numbers being quoted for COWW alloy. Sometimes it might be old information, and at other times it just seems wrong. Here is part of a post on another site by Bill Ferguson who you may remember as The Antimony Man.

>Sent: Jan 28, 2008 9:33 PM

>Subject: Re: [CB-L] New Refinery WW
>
>Original spec was/is 3% antimony, 0.25 % tin, 0.17% Arsenic balance lead.
>
>The report was the spec is still adhered to however there was 0.5% tin.
>
>This has been the 'real' specification since the mid 1970s.
>
>Have no idea why publications seem to be reluctant to request updated information.
>
>Bill Ferguson, Metallurgist

[GlocksareGood]

I always just keep unknown solder I run across out and when I get 20-30lbs I melt it down and have it scanned. Then you can use the alloy to sweeten up your shooting alloy. Easy.

[dale2242]

I bought waste solder from a couple of radiator shops for $.15 a pound way back when.
I consider it 50/50 for my purpose.

[NSB]

The solder used to manufacture radiators was/is 30/70. Radiator shops use something with a lower melting point so as to not melt the solder joints that exist from the factory. It’s all over the place what they use. Depends on the shop.