Is it ZAMAK or zinc in your alloy?

[Barry54]

We generally refer to zinc and go on and on about the horrible things it does and ruins your batch. Then there’s methods of removing zinc with copper sulfate…

But is it really zinc? Or is it really ZAMAK? The dreaded “zinc” wheel weights are not just zinc, but likely one of the ZAMAK alloys which are composed: Zink (zinc), Aluminium, Magnesium and Kupfer (copper).

So, which of the four elements of ZAMAK is really the most undesirable in a boolit casting alloy?

[hoodat]

Dang, I'm hoping that I don't have any of it in my ingots, but I couldn't guarantee it. The last time I processed a batch, I was using a newer furnace that gets pretty hot. AND I was using wheel weights that could have contained a few undesirables in the batch. I guess I'll have to find out in my casting furnace that has a lower temp. jd

[Soundguy]

If I'm going for harder alloys, I actually don't mind a little bit of copper in there. Some of my best hard reloading alloys that aren't brittle have been from copper bearing babbitt. adds a ton of hardness and also ductility.. Makes it a little tough to size, though.. So hopefully your mold drops close to what you want.

[Feral American]

I have some relatively pure zinc strips. Very soft. Softer than lead, or copper, of the same physical properties. I'm one to agree with the forward thinkers that zinc in and of itself isn't the devil it's believed to be.

But ZAMAK, that's a different story. And I'm going to attribute it's evils to the entire alloy that it is. We know that alloying changes the properties of the alloy's base elements. We at the casting bench see different melt temps, different freeze temps, the need for different casting cadence, and different shrinkages. Not to mention the different hardnesses, simply depending on the alloy being worked with.

Adding the copper, aluminum, and magnesium to the zinc does exactly what the chemists wanted it to do, result in a tough, hard, and durable alloy far beyond what zinc alone is, and devoid of lead content.

Personally, I just prefer to eliminate ZAMAK from the equation and stick with what is known to work as it has for so long. I do wonder though, if a small "safe" percentage of "zinc wheelweights" added in that still melt and cast respectably isn't something to try.

Again, I don't think that the zinc alone is contributing much either good or bad. It's the other stuff. I've melted and put into ingots a fair amount of zinc wheelweights (no lead), just for gits and shiggles. Very high melt temp a good deal higher than any lead alloy we use, and it is very hard tested on a brinell tester. Much higher Bhn than my chart goes, which stops at monotype.