Super duper smeltin pot and a question

[TaylorS]

So I have been using my Lee 4-20 to alloy and pour finished boolits and have to much raw alloy to keep working it like that. So I built a smelter holds about a 5 gallon bucket worth of WW, and is bottom pour. https://uploads.tapatalk-cdn.com/20180707/adfcb5a6d809ebbc0f699c393fcb0c40.jpg
After some modification to the original valve assembly I still have some seepage as you can see herehttps://uploads.tapatalk-cdn.com/20180707/dcb7ad0843220ae9bc72e5494e8aecf8.jpghttps://uploads.tapatalk-cdn.com/20180707/0f5ebd7790cf7ac777d246365ad3834d.jpg
How much seepage is ok with water so I don’t have molten lead poured out on the ground while I’m working a bucket worth? Or is the some high temp sealer or material I could use to bush the valve so it doesn’t leak?


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[Alan in Vermont]

I'm not sure but I think molten lead will flow through any hole that will allow water to pass.

[TaylorS]

If that be the case then I could use some ideas for something that’ll seal a little better


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[nun2kute]

Are you just plugging a hole like the lee 20 lb pot does. How did you build your valve ? Is there any way we could have more pic's ?

[jcren]

Have you lapped the rod and seat? That usually fixes a leaking bottom pour.

[dbmjr1]

^^^^ Yep. Lap that sucker so it's an exact fit to the hole using a diamond slurry, or Clover Valve lapping compound. Even then, you'll eventually have to empty the pot and clean it all up.

[TaylorS]

That 3td picture is the valve stem after getting the valve guide and handle built I found it needed a guide stem to return normally after welding a bolt on and cutting the head off I went over it with a sanding disc to smooth t out and try to shape it back but even version one leaked a little bit. I’m thinking maybe make the stem cherry and pounding it to the shape of the seat? I’ll get more pictures of it when I get home


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[TaylorS]

https://uploads.tapatalk-cdn.com/20180707/34d7c6dcff57b09f70c55fcf453a261a.jpghttps://uploads.tapatalk-cdn.com/20180707/5354d98f79566fc5b9b9816c1eddf2b4.jpghttps://uploads.tapatalk-cdn.com/20180707/262630d020fd3af71aa7d31b31eab45b.jpg here 3 more pics of the valve assembly where am I gonna find lapping compound have a buddy in the big town and need to tell him where and what?


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[jcren]

Valve lapping/grinding compound. Napa sells a generic medium grit, Clover brand is the old standard. There are many that will work but these are common at auto stores.
223351
223352

If you have never used it, dab some on the stem and seat, set it in place and twirl it back and forth like you are starting a fire with a stick. Rotate a 1/4 and twirl, rotate and twirl. Eventually it grinds the two surfaces to a perfect mirror image. Or Chuck the stem in a drill.

[bangerjim]

Any standard auto store sells valve lapping compound. Probably even WalMart. And yes........if water leaks thru, so will molten Pb. Gravity and head pressure apply to water as well as molten metals.

How are you gonna keep the melted Pb from setting up in that long bottom pipe? The heat from the Pb will dissipate rapidly and plug it up. You will need to have a looooong propane burner flame constantly heating that long pipe also.

Another question............what the heck are you gonna heat that huge thing up with?????????? And keep it to the correct melt temp????? It will take 300K BTU''s or so just to warm it up! Being so big, you will need to have heat on the bottom AND the sides. A turkey fryer will not work well. You need something more like the afterburner on a fighter jet.

Once you finally get it perfected, be sure you REALLY do a good job of sorting COWW's for zinkers!!!!! You have absolutely no way of accurately controlling the heat on that huge thing and you can easily get into the Zn melting range if not careful.

The design and construction of that valve and seat will be critical as the metals they are made of will expand when heated, creating possible binding and leaks, depending on the expansion rates of the seat and valve. A couple thousands makes a world of difference. That valve/seat assembly should be made of the same metals and turned on a lathe then lapped to minimize/prevent leakage.

Frequent cleaning will be mandatory with COWW melting, so design it with that in mind. That valve will easily plug with all the carp that is associated with melting weights. That is why so many on here use large ladles to pour off the top where the gunk is at a minimum using fluxes and reducers.

I personally like to stick with much smaller batches of re-melts for quality control and safety reasons. 75-100# of liquid metal at a time is just fine for my needs. I just do several batches.

I am an engineer and design mechanical and electronic "stuff" all the time. I like to look ahead for possible stumbling blocks when designing any equipment. Just some suggestions to keep in mind.

Good luck.

bangerjim

[BCOWANWHEELS]

aint no lapping compound gonna fix this. it needed a male and female bevel machined into components b4 install. imo

[BK7saum]

That's a little larger than my pot. It'll hold about 500-550 lbs full of molten leaf. I usually smelt around 250-350 lbs at a time and pour 8lb ingots in C-channel molds.

Maintaining temp is not a problem, due to the mass of metal being heated. I have never overran my target smelt temps. I think it takes about 15-20 minutes to get the pot and some lead up to temp. Once at temp, I can turn the burner way down and maintain proper temp. I use a burner from a fish cooker and a homemade stand of heavy rectangular tubing and heavy angle iron. I built a windscreen of flashing that is about an inch wider than the pot. That decreased propane consumption by about half. It is a bottom pour pot (Lee copy) and seals well.

I have another pot that I built first that'll hold around 150 lbs full. It makes a nice alloy pot for 100lb batches.

[TaylorS]

I sort everything twice just to be sure and it’ll be heated by a ton of wood and a hair dryer with the heat being right below the spout I think it’ll stay hot enough to keep it molten til it’s clear. I don’t have direct access to a lathe or I would have built it one piece and had everything mated smoothly. Got a buddy bringing lapping compound from the big city so I’ll get out and at it early and try to smooth out the rough edges on the stem and seat. Should that fail I’ll make some calls and see if I can set up some lathe time and rebuild it from the ground up.


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[TaylorS]

aint no lapping compound gonna fix this. it needed a male and female bevel machined into components b4 install. imo

One was roughly machined into it before everything was welded up I don’t have to fancy a tools and most of this was done before coffee was ready over several weekends


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[Hairy Dawg]

One option would be to buy the valve stem & seat for a lee 20 lb. pot. I bought the set for a large smelting pot project that I never got around to finishing, but they did seal off water tight. If I remember correctly, it only cost about $10.00, but that was 7 or 8 years ago.

[TaylorS]

Would that provide adequate flow to fill out molds?


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[BK7saum]

I dont think so. My valve is a 1/4" NPT fitting screwed/welded into the bottom of the pot. I lapped a 1/2" rod to the inner ID of the fitting. I tapered the rod on a grinder wheel, then lapped it to the NPT fitting with a drill and lapping compound. Not a precision fit, but is water/molten lead tight. Works just fine.

[TaylorS]

Same parts mine has it’ll get there [emoji3]


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[Hairy Dawg]

Would that provide adequate flow to fill out molds?


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I'm thinking it would. Remember that you're going to have a tremendous amount of head pressure on that valve with lead.

[lightman]

There have been several threads, and even some stickys on smelting pots. A 45º point, either turned or ground, on a steel rod going into a cleanly drilled smaller hole seems to have worked well.

I've always though I would like a bottom pour smelting pot. But, you still have to move the molten lead. You either have to move a ladle full of molten lead to the ingot mold or you have to move the ingot mold. I continue to use my pot with a ladle. I bought a nice bottom pour ladle that holds maybe 1# more lead than my ingot molds. I pour up to 8 Lyman style ingot molds in a setting. The first is usually solid by the time I pour the last one. After 4 or 5 cycles I may have to wait a few seconds/minutes for them to cool. This way, I'm moving molten lead with a tool with a handle that distances me somewhat from the lead.

By the way, my pot holds about 400# of lead and I usually do batches of about 350#. My homemade jet burner will melt it in 20 minutes or so. You should have no problem melting your pot full.

I do hand sort my weights because a zinc weight trapped on bottom of 350# is going to get melted.

[TaylorS]

So for the doubtershttps://uploads.tapatalk-cdn.com/20180710/e7c01eeee81d80671d493ebd2f5f3f09.jpg https://uploads.tapatalk-cdn.com/20180710/c28fd15623b0d662fc0bc8dd1c51c809.jpg

So lapping with 3 grades of valve compound seems to have alleviated my issue I’m going to do it again a littler earlier in the day and double check my leaks but I think that’s gonna cure it. Big thanks to y’all for the info!


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[country gent]

One trick when lapping the valve rod is to blue it before starting and this color will show progress and low spots a lot better. Starting with very coarse compound speed it up a lot and woeking thru the finer grits gives a better finish and seal. Adding some weight to the handle or top of rod helps stop the floating effect of the steel rod in the lead also.

[Messy bear]

I think you will be ok. Start slowly with small aamounts.
We have a similar set up that holds 900 lb. We found that just a branding torch and 100 lb bottle of propane will heat it easily. It didn't until we build a heat jacket for the sides a lid for it. Those two things made lots of difference. We smelt when there's snow on the ground

[TaylorS]

The stem looks more like a nipple now but it seals I fired it up to bring the steel up to temp and burn off the galvanizing on the drain pipe melted about half off a dozen pole top pins before it started to rain. I’ll try some WW if it stays dry today


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[TaylorS]

Got some melted I’d guess about 30lb poured into ingots before I had taken the fire down to much to pour more but the valve works great diesels a little bit but pours good. Then it started to rain I may have to upgrade to a turkey fryer later on to help with heat control


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[GregLaROCHE]

If you are going to use lapping compound, the original way to lap automotive valves was buy hand. Back and fourth. Later new electric ones were invented. They too moved back and fourth. Not continuously turning in the same direction. I’m not sure of the mechanics behind this, but you might want to research before you use a drill motor in just one direction.