Strange Dross

[Wolftracker]

Maybe someone can tell me what this is. I melted about 15 lbs of ingots in my bottom pour pot and a brownish yellow dross kept forming on top as I cast. I mean a lot of it! The bullets seem OK but I kept removing this stuff from the top as about 1/4 inch of it would form every 10 minutes or so. I don't recall where these 1lb lyman ingots came from for sure. They may be from a batch of wheel weights I melted years ago that were rather dirty but I took care to flux often when making them. Anyway, I went to drain the pot and flow went to heck so whatever it is may be plugging the spout. Also, the remaining alloy in the pot has a blue appearance on top after it cooled. This is a Lee Pot and I was running it fairly hot at the #7 setting. Thanks for any thoughts you have to share on this.

[hutch18414]

I had something like that with some ingots I bought at a yard sale. Run Five said it was lead oxide, and I have to agree, the white oxide on those old ingots was heavy. If you have more of that batch of lead try using beeswax to help reduce it back into lead. I didn't have as much as you are describing, but it was nasty looking. Let us know how it turns out.

[OS OK]

It's a good idea when making ingots to figure a system of marking each distinct batch as to what you blended into them. Some go as far as testing them for content with the junkyard 'XRF' method, others will test BHN and then others don't pay much attention.
Whatever...whether you mark them with a 'Marks-a-lot' or a 'steel stamp set' is not the issue...the fact that you can come along years later and have at least some idea of what they are will help a great deal.

The other thing is the #7 mark on the Lee pot can reach 800*F and climb from there...depends on the pot and depends on the time it is adjusted so high unattended...some here use a PID Controller and know and control their pots to the degree and others merely use an analog thermometer...either way, without the PID Controller, once that Pb melts the temperature control can be adjusted down to 2 or 3 and there will be adequate time to run a pot full of Pb before the temp. gets too low.

[HeavyHev]

I wouldn't drain the pot. I leave that last 1/4 inch as it doesn't allow debris to get into the spout and it will help with the melting process of the next batch because there is more surface area touching the pot compared to a stack of ingots.
I use the #7 position for actual casting. I like it there because it keeps my lee molds hot. Aluminum dissipates heat quickly and the hot lead ensures that I don't get wrinkles. I keep a layer of sawdust on top of my pot while casting to ensure no more oxidation (that blueing you were seeing).

[runfiverun]

too much heat.
I rarely use a thermometer any more but it comes in handy from time to time.
I use it when I get a new pot to check my casting temps[and mark the dial] or when I have a new or unknown alloy to deal with.
it also use it in my 20 lb pot when I cast 22 boolits.
I keep the mold and speed to a certain cadence and hold my alloy temp to a narrow window.
if it wanders over or under the window I set the mold down on the hot plate and let the pot settle back down.
other than that it sits on the shelf.