Adding Pewter

[RydForLyf]

When adding tin, in this case pewter, to your alloy, how are you figuring out how much? Do you go strictly by weight, ignoring the different densities, or do you use a more calculated approach?

I’ve just scored my first pewter and I don’t want to waste it.

[oley55]

I too am interested to see replies on this.

As recently as today I have been playing with my calculations for adding pewter. Unless I/we see otherwise here, I planned to simply do gross calculations. i.e. for 2% tin, I would multiply 16oz X .02 = .32oz tin/pewter per pound of alloy. I think there are too many variations in what our particular pewter's tin content is (91%-98%).

I have cast most of my pewter into the heaviest bullet mold I have, a Lee SWC 44mag that casts 264gr COWW or 203gr (.45oz) of pewter. So for five pounds of alloy I will add 4 pewter boolits (1.6oz). The per boolit weight math doesn't quite work out (1.6oz vs 1.8oz), but it's close enough, me thinks.

But I do wonder if my target of 2% tin is too high and therefore wasteful.

[CastingFool]

When I mix my alloy, I use 10lbs of coww, 10 lbs of soww, and about 6 ounces of pewter. I don't know the fps, but expansion is minimal. Boolits look good.

[oley55]

When I mix my alloy, I use 10lbs of coww, 10 lbs of soww, and about 6 ounces of pewter. I don't know the fps, but expansion is minimal. Boolits look good.

so that works out to 1.8% tin. What is your pencil/bhn for your 50/50?

[imashooter2]

Weight, and I calculate the pewter as pure tin. 4% Sb and 2% Cu in 2% of your alloy isn’t worth thinking about.

ETA: I set my scale to metric when weighing out alloy components. 2% of 5,200 grams is a lot easier to figure than 2% of 4 pounds 3 ounces.

[StuBach]

I just go by weight and use the excel calculation sheet to figure what to mix in.

[CastingFool]

so that works out to 1.8% tin. What is your pencil/bhn for your 50/50?

Never tested it, cuz I never worry about it. It does seem pretty hard, so a fingernail won't scratch it.

[jsizemore]

I calculate the alloy to ounces and then add 1% pewter in 50/50 for fill out. 10lbs = 160 ounces so 1.6 ounces of pewter. I add 2% to COWW alloy for 9mm bullets. So double the pewter I put in 50/50. Everything is by weight.

[kevin c]

By weight. I mix large batches of casting alloy, so I work in pounds and decimal fractions of pounds. Being a bit OC and having a science background, I've had my pewter batches analyzed, cast into bars plus small coins of various weights, and add to the lead based on the tin content, getting very close to what I'm shooting for (usually 2% final concentration).

While my application doesn't need bullseye type accuracy, it scratches an itch to know that my alloy is consistent from batch to batch, and I get to use a little of the algebra that I learned all those years ago.

[Land Owner]

I melt 100 pound batches, by weight, of 50/50 - Pb/COWW and turn 100's of pounds of components into ~3 pound ingots in a single afternoon/morning. When cool, I weigh each ingot, mark its weight in pounds and ounces on the individual ingot and on paper to include in an Excel spreadsheet. Nineteen (19) or twenty (20) ingots (~60 pounds) are stored in a single 308-cal. steel ammo can. The cans are labeled (A, B, C, D, etc.) and stacked three high in storage.






When adding an ingot(s) to a bottom pour pot the ingot weight(s) is/are converted mathematically (magically) to decimal pounds and 2% of that - by weight - in Tin/Pewter is added to the pot. Would it be "easier" to add 2% Tin/Pewter when the 100 pound batches are made? Perhaps, but pewter, like unobtanium, is fewer and further between to locate and melt into 1.5 pound ingots (pure!?!), then bite off chunks with snips until the Tin weight in ounces is achieved to reach 2%.





It is a "Close to the Pin" and very few "Hole in One" means of alloy production that works for me. Alloys of Lead and Tin are very forgiving.

[William Yanda]

I calculate the ozs. of lead and add tin proportionately. 10lbs of lead is 160 ozs. For my purposes, since I am guessing at the antimony in 50/50 wheel weights/soft lead, I add 1/5 (intended 3 oz, originallly posted 1/3) of a 1 lb roll of lead free solder and call it good. I would bet that 3 oz. of pewter would work equally as well.
I scored a pewter pitcher by Jostens yesterday that probably weighs a pound, that will alloy a couple of pots of lead.

[bangerjim]

I just guesstimate the % alloys to add and cast a few. If they do not look as I wish, I ad a bit more pure Sn. I really never weigh any of it. knowing what all my ingots of various "stuff" already weigh when I made them. My % Sn runs from 1-3% most times, but I don't worry about it, as I have several hundred pounds of pure Sn stored away! At 2%, that's a lot of cast boolits!

This is not rocket science. Just have fun and don't sweat the tiny details of precise weights and %.

[JohnH]

Alloys of Lead and Tin are very forgiving.

Probably more than we realize, even after we realize it.