Use of Tin?

[txbirdman]

Recently I acquired 20 lbs of pure tin, individual wrapped in 1# squares. I've never really added tin to my alloy (usually just use straight wheel weights). I'm aware that tin aids in mould "fill-out" but have no idea how much to use per 10# of wheel weights. Also I received some antimony, which I know makes the alloy harder. Once again I'm not sure what ratio I should be using for my 30/30 at about 1850 fps. I have access to a hardness tester I just need a place to start.

[felix]

About a pound of tin to 100 pounds of unknown lead would suffice as a safety precaution for mold fillout. After modifying that alloy, use more tin only when NECESSARY for fillout, unless you are playing around making a zero slush alloy for lack of anything else to do. ... felix

[Willbird]

Since I got the 454423 mold and had such good luck washing it with dish soap and smoking it I have done so with my other Lee 6 cyl molds as I run them and I have not since added any tin to my WW.

some of the 6 cyl for some reason or another (I suspect venting) fill better from one end than the other. If I had not tried to run them the other way I wouldnt have known I could get the offending (usually at one end or the other) cavity to fill without any extra tin.

Bill

[Bass Ackward]

Recently I acquired 20 lbs of pure tin, individual wrapped in 1# squares. I've never really added tin to my alloy (usually just use straight wheel weights). I'm aware that tin aids in mould "fill-out" but have no idea how much to use per 10# of wheel weights. Also I received some antimony, which I know makes the alloy harder. Once again I'm not sure what ratio I should be using for my 30/30 at about 1850 fps. I have access to a hardness tester I just need a place to start.

Tex,

I am not sure I would use any tin. Unless A: you needed it for a specific mold fillout or B: wanted to hunt with air cooled WW. Then the tin makes the mix tougher and it hangs together better if it contacts bone. But tin won't rot and it doesn't eat anything. :grin:

If you do decide to add it, be careful not to exceed your antimony percentage or you will get soft spot formations. And with WW today, the only safe way to guarentee that is to add no more than 1%. So the math is fairly easy.

And as for 1850 out of a 30/30, why you could even mix that WW 50/50 with pure lead and still do that velocity with slower powders like 3031. If you wanted to run faster powders, just water drop that mix. Gives you about 14 -16 BHN. That should be hard enough to get you down to unique territory anyway.

[Bent Ramrod]

The tin I have is in the form of foil, and a box of those old-fashioned ointment tubes, never filled or crimped.

Tin is pretty expensive stuff. I've only used it to titrate into pure lead for experimental shooting to find the "ideal" temper. (It seems to be 20:1 for me, as a general rule.) I would maybe use such a mixture for competition shooting, but just try to get an approximate hardness to the 20:1 primary standard by blending wheel weights and range scrap for most of my practice or plinking. Unless the wheelweight alloy doesn't fill out the castings, I'd save the tin for "serious" purposes.

I've never tried it myself, but have heard that elemental antimony is hard to get dissolved into lead. Seem to remember that the lead has to be almost red hot, with a layer of charcoal dust on the surface, and the antimony powder stirred in. Some guy in Sierra Vista AZ, I believe, sells lead and antimony already alloyed. Once the alloy is formed, it melts right into any further lead at normal casting temperatures.

[buck1]

""I've never really added tin to my alloy (usually just use straight wheel weights). ""
Tin is dangerous! You could melt it in to a big ingot and drop it on your toe!!!
Send it to me, I will dispose of it for you! I wont even charge you anything!! Save your toes!! LOL ,,,,,Buck ;)