Bottom pour technique

[CLP]

How do you guys manage your pot of lead?

Maintain a level close to full by regularly adding back sprues and rejects and the occasional ingot?

Drain it down to near empty then refill?

I usually cast until it's no less than about 3/4 full before adding more lead- I like the high head pressure and I have a couple of finicky moulds (HPs) that cast well that way. Plus with a bigger reservoir there's less temperature fluctuation. But there's no break when casting that you might have if you run it low. Just curious.

 

[BigBore45]

I never let mine get low unless a lead change is coming. Don't like the dirt and stuff getting in the pot. Also way easier to melt the next ingot with more hot lead there. When I'm casting a bunch of the same I don't get below 4-6 lbs low.

 

[VINTAGE-SLOTCARS]

I have an old "Ohio Thermal" pot (RCBS now) and try and keep it about 1/4 until I refill. I put ingots on top to warm them up before using them. I use a top cover made of aluminum and flux every refill. This has been my system that has worked very well for me.

 

[blue32]

I'll add a couple sprues every 3-4 cast. If I drop an ingot in my 10 pounder while casting it will likely throw off the temp of the whole melt.

 

[JimKirk]

I don't cast as much as I used to ... but I believe the best way is to have a propane burner pot with extra lead already fluxed and clean .... ready to add to your bottom pour pot .... less temperature changes and less time getting back to making bullets ... but it does add to the whole process.

Back when I was really casting ... I usually made it an all day ordeal ....

 

[brewer12345]

I tend to drain the pot most of the way, add ingots, take a break, flux and resume casting. I have an 8 cavity on order. When I start casting Sith it I may preheat ingot just to keep up.

I don't like interrupting my cadence to throw in sprues as long as the mold is not overheating.

 

[jmorris]

I don’t drain the pot all the way because it takes too long to remelt an ingot when it has little contact with the pot.

I built my contraption with a pot that holds 60 pounds total, add back the sprues as it goes (bin is divided) and generally stop and add an ingot (~20lb) before the pot is 2/3 empty.

 

[cfullgraf]

When I was casting using a ladel, I’d run a pot fairly low.

Since I got a bottom pour pot, I cast until the discharge rates begin to drop off. At that point, I refill the pot with sprues and additional ingots as required.

I use the time to straighten up the work area getting ready for the next batch of casting.

 

[<*(((><]

@jmorris you never cease to impress with your abilities, I hadn't seen that "contraption" of yours yet, but I've seen several of the others you've made. Wonder how quick you paid off the time it took to build it with it's efficient use of your time in running?

 

[ReloaderFred]

For casting at home, I use the Magma Master Caster with it's 40 pound pot. I don't let it get below half, and I always have a couple of 8 pound ingots sitting on the edge, warming up. Casting sessions usually run about 8 hours, with a break for lunch and a bathroom break or two.

For casting at the shop, it's the Magma Bullet Master Mark 6, with it's 90 pound pot and 8 double cavity molds. I use the same 8 pound ingots for it and preheat them on the edge, and then put them into the pre-melt side of the pot to keep the temperature fairly even. Controls on the Bullet Master are digital, so it's easy to see the temperature variations. Sessions with the Bullet Master usually result in 20,000+ bullets.

Hope this helps.

Fred

 

[CLP]

I don't cast as much as I used to ... but I believe the best way is to have a propane burner pot with extra lead already fluxed and clean .... ready to add to your bottom pour pot .... less temperature changes and less time getting back to making bullets ... but it does add to the whole process.

Back when I was really casting ... I usually made it an all day ordeal ....

This is definitely not a beer-friendly endeavor...

 

[snuffy]

When I'm casting with my Lee pro 20 that has been modified with a PID temp controller, I drop the sprues into an aluminum tray. They stay there until its time to add more lead. Ingots are in an old pan that sits on my hotplate that I use to pre-heat my molds. They get to around 400 degrees sitting there waiting to be turned into boolits.

Adding sprues back into your pot as you cast is not a good thing. They are colder than the melted alloy, so they sink to the bottom and can drag dirt with them. Agitating the surface of the lead in the pot makes the alloy oxidize quicker which means you should flux sooner/more often.

When the lead level in the pot drops below half full is when I add more lead. Then the sprues go into the pot as well. The PID temp controller then kicks in as the pot cools because of the cold sprues. I flux after the temp is within 50 degrees of the casting temp. Fluxing at too low a temp doesn't really get the melted alloy cleaned up. If using some sort of wax or other petroleum product, it smokes and won't burn.

I use cedar shavings sold in pet stores for hamster bedding. Let it burn to a black ash, then stir that ash into the lead. I remove the first burn with any dirt left from dirty ingots, then put another handful of shavings on top, let it burn off and LEAVE it there! It acts like a shield from the air so the lead doesn't oxidize as much.

 

[JimKirk]

This is definitely not a beer-friendly endeavor...

Certainly not !

My pot I use on the propane burner has pour spout and a good handle ... I can put a lot lead into bullet shapes with it and the old Lyman bottom pour ....

 

[rsrocket1]

I drop the sprue directly into my PID controlled 4-20 and the 6 cavity sprue tends to stand up in the pot and not drag dirt (I don't know where dirt would come from if the lead goes from the spout directly onto the mold and back into the pot). The PID definitely helps keep the temperature at a perfect point so that I don't have to keep adjusting the pouring screw as the head pressure goes down from a full pot down to almost completely empty. I do Iike to keep at least a 1/4" of lead on the bottom before refilling the pot with ingots,sheet lead or reclaimed shot. I just figure a 20 minute break between ~18 pounds of pouring lead is a good time to rest and stretch.

 

[Schwing]

I am in the club that adds ingots/already melted lead constantly. I also have a buddy who casts with me so we team up. Using 5 or 6 molds, one of us does the pouring and sets the full molds aside where they can cool some before opening. The other cuts the sprue, dumps the bullets and closes the molds for their next use. Using 5 or 6 molds gives them just enough time too cool without allowing the molds to cool too much. We used to keep a toaster oven full of ingots to keep them ALMOST hot enough to melt and just added them regularly. Using this method, we would usually dump the sprue directly back into the pot which kind of slows down the process. We have recently started using a dutch oven on a propane burner and just melt 40 or so pounds at a time in it. We then ladle it into the bottom pour pot and toss the sprue into the dutch oven every now and then.

We both love reloading but hate casting bullets. I also have to watch my lead levels so I prefer to do one or two monster casting sessions per year instead of doing a few here and there. When we do it this way, we can usually cast around 1k per hour. Without stoppages (things like fluxing, sticky molds, potty breaks etc) it is more like 1,400.