Got impatient during round 3

[jeeedbb]

Third round of smelting WW. Separated out 10 pounds of PB WW out of pail of 85# of WW. Melted them down at low heat. Had a thermometer it read 550 F. I thought the melting point for lead was 621 F, but it did not hit me until this was over. I just knew I wanted to be well below 700 F. Got a bit impatient and decide since Fe and Zn will float and the temp is low, would slowly add the balance of the 40# and skip the sorting. Figured it would be easier to skim them out. After I skimmed all the metal clips, solid WW left intact and debris I decided to test out ??? if the ZN WW would float in this low temp melt. The WW had “Zn” on the side of it. I placed it in w/ the skimmer and it floated around until I taped it with the skimmer. Then it sank or so I thought. Wrong it dissipated into the melt. I was able to skim out what looked like most of the Zn as it came to the top.
Double checked my thermometer today with two other in boiling water, all three w/I 5 degrees F of each other.
1. Anyone have any experience with Zn WW melting at this low temp (550 F) or Pb being liquid at this temp?

2. How little Zn will have an effect on boolits (.500 & .44)?
3. Does Zn hurt the barrel if it makes it into boolits?

It was a great batch of WW. Out of 85# only 4# of non PB (that I know of). 5 of the NON PB WW where ZN the rest where Fe. Not sure if the batch is junk. Looking for some thoughts from the experience folks.
Thanks, jeeedbb

[runfiverun]

zinc is soluble in ww alloy you can use over one percent in an alloy and not even know it's there.
you may have to turn the heat up slightly to get good boolits.
the zinc will add some hardness to the alloy.
if i find a couple in a bucket i just leave them in there.

[Defcon-One]

I have used a pot full with a bit of Zinc in it and had no problemsb(I missed two when sorting and saw them melt as I was trying to get them out of the pot). It was 1 or 2 medium sized Zincers in a 20-25 lb. pot of Lead. It cast fine & shot fine. It will not hurt the barrel, either.

Scared me enough that I'll never do it again. I sort very carefully now. If it casts OK, then you don't have a big problem.

However, I've never thrown one back in on purpose to see what would happen! Now you know.....

[rmark]

IIRC, my Lyman thermometer show the casting temperature range for linotype starting about 550 degrees, overlapping into the pb range starting about 620 degrees. I melted about 50 lbs of wheel weights today, keeping the melt temperature about 600 dgrees. I had a few floaters I discarded but ended up with about 45 lbs in ingots.

Lead with bad zinc contamination is described as oatmeal like, which I have happen once in the past and ended up discarding the mess. If its one or two weights in 20 lbs you probably can cast at a higher temperature and be ok. I wouldn't think it would cause extra barrel wear.