making a bottom pour pot

[kendall yates]

Has anyone ever put a valve on the bottom of their cast iron pot for filling molds??
I have a few ideas but dont want to waste a pot for a trial and error idea.

[docone31]

I did.
I took a cast iron pot, brazed a nut over an hole I drilled. It was pipe thread as I put a brass spigot in the hole.
When the pot was cold, you could not turn the spigot for anything, the molten lead filled it and hardened. When it was at temp, the spigot worked fairly well. I could turn it with an handle I made.
The reason I made it, was to fine the melt seperating clips, debris from the molten mass. I had tossed around just useing an end cap but the concept of wrenching an hot end cap was not popular with me.
What did not work well, was just haveing an open valley in the bottom of the cast iron pot. It seems the quantity of melt in the pot was neccessary to really clean the melt.
When I dumped the melt, the clips and debris could easily be scooped out with little melt loss.
I used a brass spigot with no rubber seals.
There was a soldering effect when the melt cooled down however. It needed to be hot enough to melt lead outside the valve.

[briang]

What do you mean by open valley? This is an idea I have been toying with as well.

[kendall yates]

i looked through my 3000 page granger book and couldnt find any small 1/2 or 3/4 valves that are rated for more than 200 degrees. I was thinking about some type of plunger that is inside the pot

[docone31]

A simple pipe threaded into the pot.
It was ok, but the melt dripped mostly out before the temp was correct. Lots of freezes in the pipe.
Much better with a gate valve/spigot. Leave it closed, crank up the heat, go have lunch, open the valve.
The melt flows out, the clips are bigger than the hole.
Made some good ingots that way. Also made some large batches of the same alloy.
The pot was not that large, just larger than usual. I could only handle so much at a time. Once the pot was up to temp, it could be refilled easily. Mainly, the valve was still loose as the lead was still liquid/flexible.
None of the valves I used were rated for heat at all. Just avoid the ones with O-rings. They go away real quickly.

[imashooter2]

http://castboolits.gunloads.com/showthread.php?t=707

[kendall yates]

How well do you think the bottom half of a propane cylinder would work?? I would guess that would be atleast a 150# capacity

[jnovotny]

Make one and give it a try you'll never know unless you try. I'm going to try to make a bottom pour pot myself, I've got a couple of ideas floating around in my gourd. Will post pics when I get it built.

[Hardcast416taylor]

Hello Kendall Yates. What you should be looking for are brass petcock valves. They are available in pipe threaded end sizes of from 1/8 to 3/8" and I`m sure there are some made in 1/2" as well. I installed an 3/8" petcock in a homemade pot once. I needed pliars to turn the valve handle open and shut due to the heat. I passed the pot on to another melter after I left the place I worked at, about 3 yrs. duty of melting for myself and others. Robert

[snaggdit]

I would think that the cut propane tank would be easier to do, since you could wire feed a nut right onto the steel over a drilled hole. With my limited skills as a welder, I would be able to do this... Brazing to cast iron would require a more experienced welder than me... I know you said you have a buddy who is a welder. Still, a weld vs braze seems stronger. If the brazing came loose with 150# in the pot, it would make quite a mess. Just my 2 cents.

[oldtoolsniper]

Brazing something like that is dirt simple. Just like soldering. Just use a file to clean up around the hole since a grinding wheel makes brazing less likely to adhere well. Has something to do with carbon coming to the surface with heat. As far as it letting go or failing the chances are zero. You are applying no leverage, torque, psi, shear, or weight to the braze so what would cause it to let go?

[Cowboy5780]

I have built the ultimate bottom pour pot i started off with a 12 inch long 12 inch diameter pipe welded a flat bottom built valve with a piece of stainless steel and an old broken off air chisel bit has a handle coming thru the side of the pot to operate the valve havent tested it yet and prolly wont get to this weekend due to rain however as soon as i can ill post pics im sure it will work great for smelting and wouldnt be that big of a deal to build on scaled down to cast with

[briang]

A simple pipe threaded into the pot.
It was ok, but the melt dripped mostly out before the temp was correct. Lots of freezes in the pipe.
Much better with a gate valve/spigot. Leave it closed, crank up the heat, go have lunch, open the valve.
The melt flows out, the clips are bigger than the hole.
Made some good ingots that way. Also made some large batches of the same alloy.
The pot was not that large, just larger than usual. I could only handle so much at a time. Once the pot was up to temp, it could be refilled easily. Mainly, the valve was still loose as the lead was still liquid/flexible.
None of the valves I used were rated for heat at all. Just avoid the ones with O-rings. They go away real quickly.

Thanks, that's what I thought you meant. As soon as i find a piece of plate for the bottom of my piece of pipe I'm gonna make one.