20# pot?

[Land Owner]

Is the RCBS Pro Melt considered to be a "20#" pot? If it is, I can get no more than 10 weighed pounds of lead ingots in mine to reach its maximum capacity.

Which pots are actually 20# capacity - or are there any? Perhaps the name sticks because the pot, ingots, and supporting structure weigh 20#'s when full?

[Targa]

My Lee 4-20 pot certainly doesn’t hold the 20lbs it says it’s rating for.....apparently it holds more than your Pro Melt at about 17 lbs its at full capacity.

[Hossfly]

I’ve never weighed my Lee 4-20 pot when full to top with any alloy, but if it did weigh 20# there wouldn’t be room for any fluxing or stirring.

[Springfield]

Older RCBS Pro-melts can hold 22 lbs if filled to the brim. I have 2 of them. Maybe what you have is not a Pro Melt bottom pour. Got a pic of it?

[Burnt Fingers]

I've got both a PM and a PM-II and have no problems getting 20 lbs of melt in either one.

[Land Owner]

I am certain that its nameplate and instructions in its box (see image), assure it is an RCBS Pro-Melt.

I weigh my ingots on a beam scale that is locally "certified" with check weights made from a plastic bullet box into which lead boolits have been added. The boolits were weighed on a PACT Digital AND RCBS 5-0-5 Beam Scale. The sum of the component parts provides the "certified" check weights, and yes, they are accurate.

I have just emptied my Pro-Melt, twice, of 2/3 of its capacity. When I add 6#'s of lead-WW ingots and 1.92 ounces of tin each time (49-49-2 Pb-WW-Sn) to the 1/3 full pot, I reach maximum capacity, just below the lip. Any more and it will overflow. This Pro-Melt is no 20# pot.

[bangerjim]

Why does it even matter?

When your pot gets to 50%, add more feed ingots. Works 100% for me! The liquid weight in the pot determines the outflow rate due to gravity, so keep it FULL! Whether is it 10%, 17#, or whatever. A low alloy level (and your casting techniques) will create casting problems with some molds.

You should do all your alloy ratio calculations with cold ingots on your digital scale, and not try to mix on the fly in a 700F+ pot based on it's level. That is NOT an accurate way of mixing alloys.

And preheat ALL your feed ingots on your electric mold heating plate to around 15-20F below liquidous temp of your casting alloy. That way, pot temp recovery is almost instantaneous.

Happy casting.

banger

[Mk42gunner]

If you want to get specific, measure the volume of the empty pot then figure out how much that volume of your alloy weighs.

This could be as simple as volume of water vs volume of lead. IIRC lead weighs 23 pounds per quart.

Personally, I've never bothered. I just fill the pot and cast, I do my mixing of alloys in my smelting pot on the fish fryer.

Robert

[JonB_in_Glencoe]

Have you tried putting 20 lbs of pure Lead in the pot?
You mention WW...that's a lead alloy, not pure lead. WW alloy is less dense than Lead and takes up more space.

[Land Owner]

I never said I added feed ingots to create a specific alloy by guessing the level of the pot. All I have ever run though my pot is 49-49-2 Pb-WW-Sn. All of my feed ingots are 50-50 Pb-WW (I made them), about 3#'s pounds +/- a few ounces, each, weighed cold. Two percent (2%) Tin is added by weight to match the specific feed ingots added. The resulting alloy is "fine" for the shooting that I do and I am satisfied with it.

When the pot gets to about 1/3 full and the flow slows below a tolerable threshold, I take a break, and add feed ingots. Six (6) #'s is all that the pot, at that level, will take. Preheating them is good advice.

I was just wondering...about a 20# pot and whether the RCBS Pro Melt is one...it's not important.

[richhodg66]

Have you tried putting 20 lbs of pure Lead in the pot?
You mention WW...that's a lead alloy, not pure lead. WW alloy is less dense than Lead and takes up more space.

Would a difference in alloy make that big a difference? I know it can be significant difference in bullet weights, but three pounds or more out of only 20 seems like a lot. I don't doubt you just seems like a lot.

I have never used a pot that held more than ten pounds and have often thought about getting a bigger one, glad to know they aren't all what they claim to be.

[Petander]

If in doubt,measure.


My Pro Melt holds exactly a quart and math tells me a quart of lead weighs 22 lbs.

[JonB_in_Glencoe]

Would a difference in alloy make that big a difference? I know it can be significant difference in bullet weights, but three pounds or more out of only 20 seems like a lot. I don't doubt you just seems like a lot.

I have never used a pot that held more than ten pounds and have often thought about getting a bigger one, glad to know they aren't all what they claim to be.

That's a good question. I suspect it does make that big of a difference, especially when you work in the other variable.
The OP mentions "maximum capacity". That hasn't be defined by the OP. Is that full to the rim? or is that to a level he deems as safe and logical? I know I never fill my 20 lb to the rim. Wednesday, I cast about 800 boolits from a pot that was only half full and only used half of that, to accomplish the task ...filling the five small cavities of a 37gr boolit mold goes better with less head pressure. So in that instance, half full is the safe and logical maximum capacity.

[Land Owner]

I "fill" to within 1/8" of the rim, a capacity I deem "safe" on a stable bench. I will empty the pot, one day, and measure to the rim, then calculate volume and weight of lead. I was just observing "reality" and it "seems" that at about 2/3 empty, the pot "fills" with only 6#'s of alloy and 1.92 ounces of tin. I am pouring 50.5 grain (+/-) 22 Bator boolits, with a 2-cavity aluminum mold, by the thousands, and enjoying it. At "full" capacity, the bottom pour "gushes" its charge into the mold. I can adjust that - but won't. At about 2/3 of capacity, the alloy stream settles into an enjoyable pour. At about 1/3 capacity, I "worry" about overworking the electrical elements in the portion of the pot with no alloy, so I take a break and refill. This methodology is "working" for me.

[Larry Gibson]

Is the RCBS Pro Melt considered to be a "20#" pot? If it is, I can get no more than 10 weighed pounds of lead ingots in mine to reach its maximum capacity.

Which pots are actually 20# capacity - or are there any? Perhaps the name sticks because the pot, ingots, and supporting structure weigh 20#'s when full?...........All I have ever run though my pot is 49-49-2 Pb-WW-Sn.

You add 10 lbs of "lead" then add another 10 lbs of COWW + 2% tin?

[Mal Paso]

My Pro Melt holds 20lbs with room to spare, the Pro Melt 2 25lbs with room. Someone must have short sheeted the OP.

[Land Owner]

Larry - no...lead-WW alloy ingots and an additional 2% tin. I should edit my OP.

[44magLeo]

I might suggest either of two options, one is to fill the pot up full and cast ingots till the pots empty. Weigh those ingots.
Two is to empty the pot and start adding weighed ingots till pots full.
Either way will tell you how much your pot holds.

On my lee pot I measured the inside diasmeterr and depth of the pot. Using thse figuires and some simople match I found the pot holds 20 lbs. of lead when the pot is level full. When using it 17 or 18 lbs. is full enough. This gives my room to flux and stir if needed.
I think if you measured your pot empty and caslculated it's capacity you may find your pot my be 20 lbs to level full or maybe a bit more.
Leo

[alamogunr]

I've never thought about it. I've gotten old and by the time the pot is down to about 1/3, I'm ready to rest, so I add back the sprues and bring the level back up. A 5 min rest and I am ready to go again.

[Winger Ed.]

Maybe they call it a 20 pound pot if it can be filled to over flowing with pure Lead, and then weighed--- pot & all.