Pretty sure that I got Zinced today!

[Defcon-One]

I had a few pounds of stick-on wheel weights and a few pounds of clip-ons ww sitting around and I decided to melt them in my old 10 lb. Lee pot just to get them out of the way. I was gonna make one 5 pound ingot of pretty close to range lead composition.

Any way, I melted it all as usual with the pot set to a temp of about 700 degrees. It melted fine, then I fluxed with an old candle and cleaned out a few dozen clips and the stick on adhesive. The metal was oatmealy or lumpy on top and I could not get it to flux back in.

I had sorted the wheel weights and thought that I had all of the Zinc out and the temp didn't seem that high, but I still got this mess. I eventually spooned out about 1.5-2 lbs. of silvery gray, oatmeally mush and then fluxed again. It looked pretty good after a light skimming but a minute later more oatmeal appeared and after skimming that I started seeing dark purple layers and bright yellow to gold layers forming. It was a thick film all over the top that I could skim off into colored clumps.

In the end nothing helped and I wound up making the whole lot of about 5 pounds into decoy weights, since I didn't want to risk polluting my lead supply. It did cast OK but with some minor wrinkles which are common on the decoy weights anyway and it seems really soft now that it is cooled.

Anyone have any ideas what I got into? Would the purple and gold be from the zinc? I know that purple and gold can be from pure lead, but this metal was sure to have some Sn and Sb in it but there was a lot more color than I have ever seen before.

Thanks,

DC-1

[bumpo628]

It might just be a fluxing issue. I'd remelt it and try some sawdust this time.

Regarding the zinc wheelweights, you need to check them with a pair of wire cutters. When I'm checking, I stick a strong magnet (from the inside of an old hard drive) on the back of my wire cutters. That way I can check for iron or zinc weights without changing tools.

The rectangular zinc stickies usually have a 'Zn' in the top right corner. I have some small zinc weights that have a squiggly figure molded into the top. The zinc clipons usually say 'Zn' in the middle.

[L1A1Rocker]

If you have zinc contamination then flux with sulfer - lots of it. Do this outdoors and do not breath what is given off.

[Defcon-One]

I am pretty sure that it is not a fluxing issue. I have had no problems like this before through many, many batches doing exactly the same thing. Same flux I alway use, old candles.

This stuff is different than anything that I have seen before. Fortunately, I only had about 5 pounds in the little pot and it made nice decoy weights, so I don't feel the need to remelt or flux with sulfur, though I do appreciate the input and options. If I had 40 pounds or more, I'd need to try that.

I really just wanted to know what the heck I got into. Maybe even possible health risks.

It was all wheel weights. A few of the stick-ons looked funny both shape and size, but they cut easily with a wire snip so I threw them in. I doubt that any manufacturer is putting something like Calcium in wheel weights, but that is what it looked like. Other than that everything looked normal and I'm pretty sure that the temp was too low for Zinc, though I do not use a thermometer on the electric pot.

I guess I may never know. This may just be one of those weird things that we all encounter from time to time.

[Colorado4wheel]

You can't trust any temp on a lee pot. You need a temp gauge.

[shotman]

Me too on temp the best bet is a lead thermometer . even at 700 zinc dont melt fast. It will, but tends to float high for a while

[Defcon-One]

Looks like the alloy (3.6 lbs. stick-ons and 1.5 lbs. clip-ons) was 98.8% pure lead with only a small amounts of Sb and Sn and the heat was higher than I thought. I got away with it with all clip-ons, but with stick-ons being so close to pure, this all happend.

The end result was the lead overheated and caused my problems. The same thing that happened in this sticky post: "Gold and purple and blue... Oh My!"

Lesson learned: Cool it down, especially with pure or near pure lead, try saw dust as a flux, always use the thermometer and very carefully presort the raw Wheel Weights.

Thanks to everyone!

Update: Pool acid test this morning showed Zinc in my dross (the silvery metal fizzled pretty good), so I think that I had one or two zincs in the mix, plus the heat issue which gave me the Purple and Gold! This 5 lbs. of lead will stay in decoy weights forever!!!!