What % of zink is too much?

[Daddyfixit]

I bought some lead that was tested at 81pb 18sn (99%) so I finally got around to looking at the lab spec sheet to see what the other 1% was. It listed 0.4% zink. Seems to be alot of talk about zink "contaminating" the mix. So how much is too much? I got this to get a higher tin mix. Now I just have to figure the right amount of WW to mix with it. :-?

[Lloyd Smale]

dony know but i know that it only takes one or two zinc wws to screw up a batch of lead.

[southpaw]

I believe that zink will mix with lead just fine up to a certain percent. Once you exceed that amount is when you start to have the problems ( plugged nozzle ). I think that it was 2% but I could be wrong.

Being that you have 18% tin you are probably going to mix it with 9-10lbs of ww to get the 2% tin. That would make the zink content virtually nonexistent (.04%).

I can't remember who it was but there are a few guys on here that mix zink in with their lead. They have reported great results and very hard boolits.


Jerry Jr.

[Daddyfixit]

Thanks southpaw I have #100# of raw WW yet to melt down
Maybe someone who uses zink could chime in....please?

[fredj338]

As noted, you will likely add more lead so the % will be small, but I can tell you, one or 2oz in a 10# batch is enough to cause casting problems.

[Daddyfixit]

So some add zink on purpose?

[runfiverun]

yes some do and over 1.5% is where your problems start.
you can up the heat to cast with it, and do some other stuff to help rid the alloy of it.
but if you figure things correctly it is an efective hardener.

[Daddyfixit]

Thanks runfiverun, mine has .45% so it sounds like I should be OK

[DLCTEX]

According to Lyman zinc will alloy to 2%. after that it will separate and you'll get the oatmeal mush on to of the melt. I have cast perfectly good boolits with a small amount of zinc (dipped out all that would separate) and they are as maleable as ww according to smashing them with a hammer. The boolits have more of the whitish look of silver. It has no adverse effect on moulds or the pots, contrary to some rumors that it contaminated them and ruined them. I haven't found any desirable effect such as hardening lead above what wheel weights produce, and the pot may have to be run hotter to keep the bottom pour working.

[docone31]

I run my pot at full tilt, and run a lot of zinc.
When I run my pot at low temp, the nozzle clogs. At high temp, it works well. There is a paper out on useing pure zinc for castings!
Lead will hold up to 2% zinc. Zinc however will hold a percentage of lead! I have found, when you add tin, to the zinc, then lead, you can add more lead into solution.
I have not found it detrimental.