So called 50-50 solder......

[Harry O]

I bought about 15lbs of 50-50 solder in bars at an estate sale a while back. They were probably made in the 1940's or early 1950's judging from the information on the remains of the box they were in (which is also where I learned it was 50-50).

In order to make them easier to add to the mix in small, but uniform quantities, I bought a cheap Lee 0.690" round ball mould. From my calculations, this should have given about 1/2oz of tin per ball. When I got done casting them, I weighed several and found out that they were heavier than they should be.

I calculated backwards and found that I had approx. 42% tin and 58% lead solder. Still not bad, since I paid only $10 for the 15lbs of solder, but it is not an even amount of tin. It just goes to show that manufacturers cheating on quantities is not a new thing.

[kelbro]

Cast the same balls with pure lead to calibrate.

[Harry O]

Been there, done that. My cast pure lead 0.690" RB weighs an average of 495gr although theoretically they should weigh 493gr. Close enough. Theoretically, a pure tin 0.690" RB weighs 316gr. Haven't actually cast that, but since my lead ball test was so close, I went with that.

Remember when doing calculations that lead/tin mixtures (such as 50-50, 63-37, etc) are based on weights, not volume. A 50-50 solder will be half lead and half tin by weight. By volume, there is much more tin than lead in a 50-50 bar.

[Shiloh]

40/60 is a common solder as well. Recalculate and adjust as needed. Good advice from Kelbro.

Shiloh

[GLL]

What was the weight, measured diameter, and specific gravity you calculated for your solder balls?

Jerry

[prs]

Tin is now, and was then more precious than lead. Perhaps the ratio stated on solder label was based upon volume rather than weight; thus your weight calculations show the tin percentages to be low.

prs

[alamogunr]

40/60 is a common solder as well. Recalculate and adjust as needed. Good advice from Kelbro.

Shiloh

Strange! Many times when solder comes up someone states that 40/60 solder is probably 60% tin since 40/60(tin/lead) is rare.

I have almost 700# of 40/60 solder. I have never attempted to determine if that is accurate. About 150# is in ingots and came from an industrial pot that was in molten state for long periods. I would imagine that a lot of the tin was lost. I really don't care since I only use it to add tin to alloy for handgun plinking boolets. A little too much or a little too little doesn't make much difference to me if I get decent boolets.