Cleaning a casting pot

[Chinook]

Question from an inexperienced caster: I have a Waage casting pot in which I have been using various alloys for casting pistol bullets.  I would like to dedicate this pot to lead/tin alloys for casting BPCR bullets, without contaminating this alloy with the antimony and other impurities in the pistol bullet lead.  What is the best way to clean/decontaminate this pot (which is not bottom-pour)?

Thanks and regards,
Chinook

[Turkeyfeather]

I have run across this myself with mixing alloys and latter needing to clean the pot.

I simply heated the pot and poured out the remaining material. While it was still hot, I shook out the residual metal that wouldn't pour out and then let it cool. The last step I took is what flintman said. I shot it with a sand blaster to clean it up. When you are done there should be no sign of silver material. If there is you may opt to heat the pot again and, scratch the material loose and shake it again.

I have found that if you got 98% of the material out you would be fine unless it is a some contaminant that is not healthy.

[flintman]

DO NOT TRY BOILING WATER TO CLEAN ELECTRIC POTS!!!
 After you have let the pot cool and no metal is inside of it,add some water to it and boil it a few minutes and it will remove the dross that is sticking to the sides of the lead pot.
 I edited the above answer to do not try water boiling in electric pots,this is to prevent electrical shocks.I apologize for this oversight on my part.Someday this keyboard and my lack of brains will have to have a talk!

[Veral]

I've left the above answer in place because it sounds real good, though I haven't tried it.  If it cleans the dross out without working, lets do it!

  Keep in mind that dross or crud on a melting pot surface is oxidized metal and dirt that couldn't melt into the molten alloy that was in the pot previously, and that nothing that has oxidized can be put into the metal without lead smelting equipment.  The exception would be if the pot were used to melt zinc, in which case severe cleaning is required to keep any residues from getting into lead alloys.  Zinc contamination will cause lead alloys to crumble after aging for a while.

  When I clean a pot I just scrape the junk off with on old spoon or my skimming ladle.  Any traces of antimony or whatever that are left will not be noticed in a straight tin lead alloy.  We aren't making labratory grade pure alloy, just bullets, which aren't sensitive to tiny traces of this and that.  Perhaps of interest, commercial pure lead can contain fairly high amounts of silver, because it is in all lead mines to varying degrees world wide, but isn't worth the chemistry to remove it.  But no one would know if not told about it.  Commercial pure lead makes great black powder bullets.  Always has.

[Chinook]

Thanks, all, for these ideas.  I think a combination of Veral's and Turkeyfeather's ideas are what I'll use.  I'm not a competition BPCR shooter so small impurities in the initial pot or two of "pure" lead/tin alloy likely won't be an issue, as Veral points out.  

Regards,
Chinook

[Veral]

The small impurities I'm talking about won't hurt performance for the most precise competition shooter, and I'm not picking at your kind thank you, but telling the readership of a problem many get enslaved with.  

  Bullet casters in trying for optimum precision must be very careful not to get caught up with finate details which mean nothing to performance.  If the concern is alloying, try a lot of bullets with various alloys and use what works.  You'll find that alloy isn't finicky.  When sorting bullets for defects, segregate the defective bullets you think should be remelted into lots according to the type and or seriousness of the defect.  Shoot groups with each of these defected bullets.  It group size isn't hurt by certain defects, never sort them out again.  You'll spend a lot more time shooting than making bullets this way, and especially if using LBT molds.  I've VERY carefully designed them to make high quality castings, putting many small things into their design which an unlearned person cannot see, except on targets!

[Veral]

The small impurities I'm talking about won't hurt performance for the most precise competition shooter, and I'm not picking at your kind thank you, but telling the readership of a problem many get enslaved with.  

  Bullet casters in trying for optimum precision must be very careful not to get caught up with finate details which mean nothing to performance.  If the concern is alloying, try a lot of bullets with various alloys and use what works.  You'll find that alloy isn't finicky.  When sorting bullets for defects, segregate the defective bullets you think should be remelted into lots according to the type and or seriousness of the defect.  Shoot groups with each of these defected bullets.  It group size isn't hurt by certain defects, never sort them out again.  You'll spend a lot more time shooting than making bullets this way, and especially if using LBT molds.  I've VERY carefully designed them to make high quality castings, putting many small things into their design which an unlearned person cannot see, except on targets!