How much tin to cause gold color?

[Bazoo]

I have about 45-50 pounds of mystery alloy. I filled my pot with it, leaving bout a pound of ww +1%sn when I switched. Well it gets a golden oxide on the surface and on the dipper, a lot of it. So, i figure it's a high tin alloy. I get mild frosting. It casts wonderfully.

I'm thinking the frosting is from the little bit of alloy left in my pot when I switched. I'm also thinking it's a fairly high tin alloy.

How much tin does it take to get that golden oxide? My ww+1-2%sn doesn't turn golden. I can dimple and scratch a resultant bullet easier than my WW alloy.

I'll probably empty my pot completely and melt some more to see if it frosts too.

I'm wondering if it might be worth having a sample tested, cut it 50/50 with ww alloy to stretch out my supply, or if I aught to just use it for pistol bullets and be happy.

Preciate the input.

Bazoo

[Bantou]

What temperature were you running? I’ve had straight ww lead turn gold on me but I had it HOT. It was the first batch I had ever processed and I didn’t have a thermometer yet. I have no idea what the actual temp was but I know it was way above what I do now.


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[garandsrus]

Gold and rainbow colors normally appear with lead that is close to pure.

[country gent]

At Cambells Soups the can plant used 99.9% pure tn for soldering the side seams on cans. Never any gold color on those pots I can remember, But it was very shiny. An Uncle made mirrors as a hobby by soldering tin onto glass and his pot never had a gold color to it either.

I have seen the golds and purples in lead but at raised temps and it was close to pure lead.

[Bent Ramrod]

The “gold” color is more a function of heat than tin. Lead forms a number of different oxides, depending on temperature and time exposed to air.

The lowest oxidation state is called “litharge.” It is yellow. Longer exposures to heat and air go through higher oxidation states: “red lead,” (rust color) to brown (I think that’s called “lead peroxide,” used in storage batteries), to black. Don’t have my references in reach, so I won’t guess at the chemical formulas.

I think your “gold” surface relates to the lower melting temperature that your alloy needs, because of the tin content, and the reduced surface oxidation caused thereby. The “rust” others mention, which coats the pot but never seems to pit or corrode the iron, is probably the red lead oxide, caused by longer heat times while stirring and casting. And the brown and black stuff is what gets skimmed off after smelting and fluxing; the higher oxidation states caused by heating the already weathered and oxidized scrap and wheelweights.

[daengmei]

The “rust” others mention, which coats the pot but never seems to pit or corrode the iron, is probably the red lead oxide, caused by longer heat times while stirring and casting.

Maybe this is what has me asking in another thread.

[USSR]

Gold and rainbow colors normally appear with lead that is close to pure.

Yep!

Don

[Bazoo]

Thanks for the responses.

I'm sure this lead isn't pure. But I'm not sure how much of what's in it. I spose I'll just shoot it up. It sure makes pretty bullets. RCBS 44-245-SWC at present.

[jsizemore]

Tin will do the rainbow colors too.

[ulav8r]

If it is not pure lead, 40-50 pounds might be enough to justify having it tested. If it does have lots of tin it might be used to sweeten/stretch a large batch of coww or other alloy. Try casting several bullets at a reasonable temperature, then check them for hardness and weight. If you have some known alloy, cast a few of them also and compare them to your unknown alloy. If they are heavier than the unknown they have more lead than the unknown. The hardness comparisons will also give clues as to what might be in the unknown.

[Bazoo]

The resultant bullets are softer than WW alloy bullets. I don't know what my temperature is, I don't have a thermometer. With the same heat setting, adding 2%Sn to WWs doesn't give me the golden oxide. That's why I'm thinking maybe it's a higher tin content. Could be 10-1 for all I know. Tin is hard to come by round these parts so I'm thinking about having it tested before I waste it.

[USSR]

Bazoo,

I'm thinking you're going off in the wrong direction regarding a high tin content. Since I cast hollowpoints and use a lot of high tin alloys, I am thinking your lead is a lot closer to pure than you think. Just MHO.

Don

[RogerDat]

High tin like pewter will cast golden ingots. Very smooth texture & glossy surface. The melt won't be golden that I have noticed. The melt will be very shiny.

Gold colored ingots are different than gold colored oxide on the surface of the melt.

Texture of the ingots will be coarser for lead than it will for tin. I posted some pictures in a thread on organ pipes that show some 80% tin ingots vs some with less and some as low as 16% tin. You can see the gold tone and the graininess of the 16% vs the gloss of 80% ingots. Note there were air bubbles in the 80% tin ingots.

http://castboolits.gunloads.com/show...=1#post4765635


Even 2% Sn will cast very nice. 3 - 5 percent Sn is really impressive how it casts. Sharp fill and gloss at lower temperatures.

[super6]

High tin like pewter will cast golden ingots. Very smooth texture & glossy surface. The melt won't be golden that I have noticed. The melt will be very shiny.

Gold colored ingots are different than gold colored oxide on the surface of the melt.

Texture of the ingots will be coarser for lead than it will for tin. I posted some pictures in a thread on organ pipes that show some 80% tin ingots vs some with less and some as low as 16% tin. You can see the gold tone and the graininess of the 16% vs the gloss of 80% ingots. Note there were air bubbles in the 80% tin ingots.

http://castboolits.gunloads.com/show...=1#post4765635


Even 2% Sn will cast very nice. 3 - 5 percent Sn is really impressive how it casts. Sharp fill and gloss at lower temperatures.

This ^ All of my pewter ingots show a gold color.

[Gobeyond]

I had a gold color with range scrap, but then it changes. I think it was the temperature. My two cents.