Melting pot mush. Is it zinc?

[samwithacolt]

I scrounged a bucket of WW's from a buddy yesterday and smelted them today.
I use a small pot on a burner on the bbq. Never had problems before, been doing that for over a year.
Today I had two potfuls that were just mush. Clip ons, they stared to melt and then went into mush. I thought maybe they were'nt hot enough, but they did'nt get any better when I left them on for a while. Out of the few dozen muffins I cast from the rest of the bucket, the rest were all fine. My stick ons were nice and shiny as always, and the rest of the clip ons melted and poured just fine.
I dumped the mushy crud from the other two pot loads into a metal bucket, was going to try and melt it again, but I'm afraid there's zinc in it.
Am I right, or what else could it be? I'm inclined to chuck it or make duck decoy weights out of it.

[500MAG]

Do you have a thermometer? What was the alloy temp? If you didn't get it too high, zinc wouldn't have melted.

[ssnow]

Did you sort through the weights before smelting to remove zinc weights? If you did, then it's likely that you simply need more heat. If you did not, then zinc contamination is a possibility.

You can test for zinc contamination by using some muriatic acid, available at your local hardware store. Just pour a small amount on your alloy to see if it reacts. If zinc is present, it will start bubbling/foaming.......it will not react with lead. I recommend testing a known zinc weight, and a known lead weight to see the difference, as then you will have no future doubts about the appearance of the reaction.

[el34]

A really big question is your temp. Stickons are very close to pure lead and will melt considerably lower temp than clipons, roughly (from memory) 50deg difference. And almost-melted anything looks very mushy. Zinc melts at 787deg, much higher than you need to go for melting lead. A thermometer is a very useful tool for cases like this.

I also smelt on the BBQ sideburner. There've been times when I could see flames but it seemed the pot just wasn't heating, turned out to be almost empty propane can.

As ssnow posted muriatic acid is a good test for zinc, I got mine (gallon!) at a pool supply store. Don't throw away your lead just yet.

[runfiverun]

muratic acid is also good for seeing calcium, it reacts and makes co-2.
anyway the soft lead [closer to pure] has a higher melt point than an alloy does.
pure is 630-f, lino is 450-f.
back to the zinc thing, it forms an oatmeal like substance within the melted lead, once the percentage goes-
over 2, if you got 3-4 zinc ww's in the pot you wouldn't even know.

ww's have a slush phase before they melt [the alloy is not balanced perfectly like linotype is] you just needed more heat to get past it.