casting with a BP pot

Kevin Stenberg

Well-Known Member
Would there be any advantage if I cut a steel plate disk to float on top of my pot? I was thinking it would decrease the surface area of the lead. So the lead would not loose the sn as fast.
I also realize that the steel plate wouldn't insulate the lead as much as if you used charred wood dust.
I also figured I would have to weld something to the plate to make it easier to take the plate out of the pot at the low level of the melted lead.
 

S Mac

Sept. 10, 2021 Steve left us. You are missed.
Sounds like a neat idea. I'm a dedicated ladle caster, but I think it would work well for BP.
 

358156 hp

At large, whereabouts unknown.
In the olden days we used to pour a level of kitty litter on top of the melt to inhibit oxidization. Since it floats on top, you can add your sprues, or replenish you alloy whenever you need to, and the kitty litter is "self-healing", and returns to its original position to do its job over and over.

If you decide to try this, I do recommend you use only new kitty litter. Used kitty litter in this application carries recycling a bit too far in my opinion.
 

Ian

Notorious member
I wouldn't worry about losing too much tin, or the oxides on top, but that steel plate is a nifty idea anyway. Sprues and culls could be tossed in on top of it and melt away to run off the edges and join the metal below without worry of dragging dross to the bottom. I may have to try that.
 

Rick

Moderator
Staff member
I do recommend you use only new kitty litter. Used kitty litter in this application carries recycling a bit too far in my opinion.

Depends entirely on how upset you are with the wifey. As you can see there are ways to get even. :eek::D
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Rick

Moderator
Staff member
As for losing Sn, it doesn't evaporate, you will only lose it if you skim it off. Proper fluxing will return oxidized Sn, Pb, Sb to elemental metal within the alloy. Of the three metals, Sn, Pb, Sb the Sn will oxidize first, then the Pb and then the Sb which is because of the melt temp of each metal.
 
F

freebullet

Guest
My concern would be changing the pressure output at the bottom pour spigot. Fishing it out could be a problem. I dunno.
 

fiver

Well-Known Member
I use big chunks of steel on top of my pots kind of as a lid and a pre-heating type thing.
I have never used a heating plate [not for molds anyway]
the kitty litter thing works pretty okayish well enough I still use it on the LEE 20lb pot.
the other ones I pretty much just let oxide up [shrug] the oxides work just fine as an oxygen barrier.
every now and then [2-300 lbs of alloy] I look in the pot and figure I need to light the stuff in there on fire and scrape the sides some.

when I do ladle cast I just scrape the stuff off the top and store it in a metal bucket then re-claim it later.
 

Ian

Notorious member
As usual, we can rely on Rick for superb casting, shooting, and metallurgical facts and some pretty terrible marital advice :D

Next time I have the plasma torch out I'm going to zip a disk out of 1/4" plate, DT for a long bolt in the middle, and give it a go. I like the idea of recycling sprues as I go without side effects more than any other aspect of the idea. Like Fiver, I really don't care much about the oxide layer on top of the melt because once it forms, it really doesn't get much worse. The problem is when adding stuff to the pot through that layer. Melting sprues on the place will still allow the same amount of extra oxides to pile up, but at least the sprues and culls won't be on the bottom of the pot when they melt and turn loose of their oxidized hulls.
 

Rick

Moderator
Staff member
As usual, we can rely on Rick for superb casting, shooting, and metallurgical facts and some pretty terrible marital advice :D

I tell ya, some people just have no sense of humor but I can't figure out why I'm single. :confused:
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myg30

New Member
I use a layer of pine saw dust on the top of lee 20 lb pot. I just let it smoke n burn.
I drop my spruces as I cast. My ingots were clean when made.
When pot gets low I add lead ingots take a short break, stretch the old legs n back, then I stir n scrap if needed with a thin pine stick, add more saw dust.
I don't have to much trouble with drips as I rotate the screw needle several times to clean it off if nessary during casting if drips occur. I leave the mold on top of the pot to stay warm with cavity full and spruce plate down. I cast hot but not frosted.
Works for me in the summer. Winter casting all different.
Mike
 

Centaur 1

New Member
This would probably help when adding an ingot to the pot. Nothing slows you down like when you add a 2 pound lead cupcake to the pot. Even though I preheat my ingots on a hotplate, it still cools the pot. It's normally not a big deal, but when I'm cranking out 230 grain bullets to shoot at steel plates with the .45, I go through an ingot every five minutes. A steel plate would keep the ingot on top until it melts.
 

JSH

Active Member
I have a plate I lay over the whole top of my pot. Putting a floating disk would give me grief with fishing out and stirring.
My ingots have all been fluxed well also. That doesn't mean you won't get dross from them. I get less, but still enough that I skim off.
 

Ian

Notorious member
I have a plate located to cut out, will test this and see. I suspect that ingots and sprues will melt on the plate and deposit their oxide skins there without any dross having a chance to get pulled below the surface of the melt. My only concern with putting ingots on top of the plate is the weight overcoming the buoyancy of the steel and making it sink. Will let you guys know.
 

Dale53

Active Member
Back in the day, when I was MUCH younger and shot serious IPSC Competition, I would cast continuously. My record is 13,000 match quality bullets over a weekend (I cast, and my two sons pre-melted ingots in an open pot and kept my BP pot filled). Now that I have gotten older and don't shoot as much, I cast one full pot at a time.

I fill the pot with metal (alloying at the same time with all clean metal). I then sit down and cast until the pot is nearly empty (leave an inch or so as I believe that is easier on the pot). I keep that lot of bullets together, sizing and boxing them.

Since I only do one pot at a time, it only takes one to one half hour casting time (after the metal is up to heat). It would not be a particular benefit to me to have the plate. I don't really need a PID, either (although part of me would like to have one :)>)). By not adding a lot of cold metal to the pot, my temps stay pretty consistent. I DO add the sprues back in to the pot. However, I don't let them collect too long before returning to the pot (they are still pretty hot so don't change the temps much).

Since I have a two burner hot plate, I have experimented with pre-heating ingots, too. If I were going to more that one pot at a time, pre-heating the ingots minimize melting time for the second full pot. Or, conversely, you could just drop one pre-heated ingot in the pot at a time and keep going...

I pre-heat my molds with a hot plate and have a small manicurists fan to help maintain mold temperature and cool the sprues quickly.

Just a thought or two...

FWIW
Dale53
 

popper

Well-Known Member
Maybe just a small tin can (or SS drink cup) with holes in the bottom? Sure would keep the 'splash' down when dumping sprue in. Question if you want it to float or suspended. I just use a sauce pan & toss in when I add an ingot.