Does your lead bubble when casting?

[palmettosunshine]

Decided to cast some today as its overcast and cool out. I'm casting inside for the first time in an outbuilding in the backyard. It's probably 8 x 12 with a roof, four walls, one window and a door. I use a single, small propane tank with burner on top and its supported by a wooden base to keep it from tipping.

Fired it up and it heated up nicely since it's out of the wind and within 10 minutes the lead was molten and I had a small pile of boolits on the bench. Then I noticed something strange. The lead in the pot (cast iron frying pan actually) would develop a bubble that would pop with a puff of smoke. Not a bunch, just a few but it freaked me out as I have never seen this before. I shut it down and left the area. Am I being paranoid or is this normal?

The alloy was straight wheel weights that I had smelted on Thursday and poured into ingots. Everything was inside and dry after the smelting session.

My gut told me to get out right then so I listened to it. I do this for fun and enjoyment, not out of necessity.

Any input on this would be greatly appreciated!

[runfiverun]

if you were boiling lead your temp had to be over 1,000-f [1380 airc]
the ten minute melt time tells me you have some high heat going on too.

[palmettosunshine]

Well now that makes sense. I've only ever done this outside before and the slightest breeze would make it hard to keep the lead molten.

Wouldn't my pan be glowing red hot though?

[res45]

A Lead thermometer is always handy some don't need it but I've found it to be very useful since I started using one. It helps keep you from getting you lead to hot which can cause multiple issues in both smelting and casting.

[Beau Cassidy]

Getting lead hot enough to boil means it is really hot. I have never gotten a melting pot that hot. Not to say it can't get that hot but surely it would take more than 10 minutes.

Were you putting in ingots?
What kind of pot?

[Mooseman]

I had this happen once when I used a different cast iron pot that had formerly been used for cooking. I believe it may have been some of the old oil seasoning working its way out of the pores in the pot. Mine did it about the time it was fully melted and skimmed off and the whiff of smoke smelled like burnt cooking oil, but it could have been from something on or in with the wheel weights. I turned my heat down a bit and stepped back and watched it. Then I fluxed again and scraped the bottom of the pot , and skimmed it. Never had it happen since.

[palmettosunshine]

Turned the heat down and all is good. Next on my list is an electric melter. Thanks everyone.

[jdgabbard]

I've had the same thing happen to me. My thermometer read 700 +/-.... I think it has to do with there being something down on the bottom of the pot that is burning a little. Oil, grease, trash from not properly smelting the weights. I had it happen when smelting the other day. I know I wasn't at 1000+ degrees, as the zinc weights were not melting. It happens, just make sure you scrape the pot, and flux accordingly.

[snuffy]

The boiling point for lead is 3180 degrees. Some form of organic compound under the molten lead was vaporizing. If it had been water, it would have long since have evaporated. No impending visit from the tinsel fairy!

The vapor point for lead is 1000-1200 degrees. The problem with a propane burner is temperature regulation. You'd spend so much time trying to regulate temp, you'll never get any boolits made.

Boolit weight and size are temperature related. If you want consistent size and weight, keep the temp. at an even setting.

[geargnasher]

The Tinsel Faery burped.

Some speck of crud under the melt gassed-off.

Gear