Bubble Bubble Cauldron Bubble

[Jig Man]

I have run short of lead ingots so I decided to cast some today since it is cold and windy here in SW MO.  I had about 150 # of various scraps (radio active medicine containers,X-Ray room liners, plumbers lead, some wheel weights and a bunch of old pyramid shaped sinkers).

 

I melted them down with my fish cooker in a cast iron pot.  The pot had not been used for at least 10 years when I cast some babbit spoons.

 

For about the first hour the lead would bubble up in the middle.  Once it even errupted and splashed lead on the floor (glad I was outside at the time).  Then it settled down and I had no more bubbles.  For a while it looked like my wifes early stages of making gravy.

 

The lead has been in side for 9 years so I haven't a clue as to what made the bubbles.

 

Any ideas??

[basskat]

Sounds as if there was some moisture from somewhere. Doesn't take much, a drop of sweat will create a mess when mixed with lead.

[Kasilofchrisn]

Yes definetly moisture for sure.

I take it you added more scrap to an already liquid batch of lead? That would be where the moisture came from.

I always start with a cold pot when melting scrap. When the first batch is done and the pot empty I turn off the heat then reload the pot and start over.

That way any moisture trapped inside will evaporate out as the htemperature rises long before the metal turns liquid .

[Jig Man]

I prolly should have between batches but I was kind of pressed for time and wanted to get all of it done this morning.

 

I thought moisture would blow up not just bubble.