Tin alloy and antimony sources for North SF Bayarea?

[pacrat]

Learn to test your lead for hardness and zinc when buying from random people and youll be fine. I've unknowingly purchased zinc and lead with zinc in it in the past because the price was low and I didn't check it.

How does one go about [zinc testing]?

inquiring minds

[bohoki]

with baked on powdercoat just use the lead you got unless its not filling the mold then you need a bit more tin just add some solder

zinc contamination is a concern for unknown chunks of salvage but if you shoot it within a couple months of making it it should be fine

zinc will make your liquid and solid lead look like oatmeal in that it it will kind of be lumpy as bits freeze at different rates

[browndude]

Took my kiddo to the free play arcade in alameda (high scores) and caught the nice ladies at Rotometals about to leave early b4 along weekend. Got some antimony and pure tin. Got my pencils out for the lead scrap I bought from Alco mare island(bring cash!)

[BIGOX]

How does one go about [zinc testing]?

inquiring minds

You can test for zinc with acid. You can use muriatic acid on exposed lead if there is zinc you will see a reaction (small bubbles). Lead will have no reaction to acid.
You don't what to accidentally get zinc contamination lead in a bottom pouring pot. Zinc become I sticky mess to clean up and will gunk up your pot and tools. A small percentage of zinc can be unnoticeable.

[BIGOX]

with baked on powdercoat just use the lead you got unless its not filling the mold then you need a bit more tin just add some solder

I think OP said he had pure lead so he should harden up his lead up a little even if powder coating to help prevent leading and to operate at higher velocity and pressure.

[browndude]

Yup def powdercoating after sizing slugs

[browndude]

Is a chunk of toilet bowl wax seal or 20 mule team Borax good for fluxing?

[BIGOX]

Is a chunk of toilet bowl wax seal or 20 mule team Borax good for fluxing?

A wax toilet seal is made of bees wax so it's a great affordable source for flux and bullet lube.