Custom smelting pot?

[ftut]

Hello all. I’m new to casting so be gentle with me. I always figured I could purchase boolits and have for years but it is just getting to expensive. So like many I’m sure, I searched and found this wonderful site and I’ve got the casting bug. So I’d like to talk a little about smelting pots. I have a friend in the auto industry that is gathering up all the free ww he can find. I’ve been smelting these in a small pot I got from Goodwill and using a ladle to fill my lyman ingot mold. After finding this site and seeing all the ideas you guys come up with for bottom pour smelting pots I’ve got to figuring that I can make one. So I found a high pressure gas cylinder that failed its retest and is now scrap. The cylinder has about a half inch wall thickness and 8.5 inside diameter. Once I cut the bottom off the cylinder I will be able to use the bottom as a nice steel pot and even put a bottom pour spigot in it. My question to the group is this. How tall should I make my pot? How high can I made it and chuck it full of ww and just let them melt and run to the bottom? I would think it would depend on how much heat can be applied. Is there any chance of getting the bottom to hot while trying to get the top up to temperature? I’ll be using a turkey cooker burner that I know I will have to beef up to hold the weight. Can anyone in the group share their experience and give me some guidance? This cylinder is about 50 inches tall so it could be a really big pot.

[Dan Cash]

Were it I making the pot and I am getting ready to do the same as you as soon as I can secure an appropriate cylinder, I would not make it over 10" tall. If the pot is too tall in relation to its diameter, you will have heating problems and it will be very unstable without radical base support. Propane cylinders make the best convenient smelting pots for reducing scrap to a useable condition. I think the high pressure gas cylinder will make an outstanding casting pot; either as a dip pot or modified as a bottom pour as you like.

[blikseme300]

Are you thinking of a bottom pour while using a gas heating source? I don't know if this is feasible. The main advantage of electric heating is that you can control the temperature very precisely using a PID. Band heater elements or flexible/bendable elements are the way to go with tubular pots.

I made my shelters a few years ago and there is no doubt that they allow me better casting than any commercial (economical) units. You can see how I did it here: http://bliksemseplek.com/boolits.html



Bliksem
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[hiram]

Make the pot shorter than your ladle so you can get down to the bottom. Also consider how much handle you want to hold onto.

[ftut]

I was thinking I would drill and tap a 1/4 pipe thread in the bottom and use a 1/4 pipe x 3/8 tube stainless steel fitting with a short 3/8 tube. the tube wouldn't have to be over 4 inches long and would run down beside my burner. Then with a valve inside very similar to what Bliksem did with his I would have a bottom pour pot. I wasn't concidering casting from this pot, only smelting ww down to ingots. Would I have to be greatly concerned with the temperature just to smelt scrap?

[RayinNH]

I have two pots that I made. One is 6" in diameter and 8" tall, the other 10" diameter and 4" tall. The shorter one is much easier to use when skimming wheelweight clips and bullet jackets off of range lead...Ray

[Jim Flinchbaugh]

I made my shelters a few years ago and there is no doubt that they allow me better casting than any commercial (economical) units. You can see how I did it here: http://bliksemseplek.com/boolits.html
Bliksem


What band heaters did you use? I've looked at several sights. Lots of choices!
What wattage is necessary?

[Jim Flinchbaugh]

ftut,
here's the thread on the one I built last winter
http://castboolits.gunloads.com/showthread.php?146446-My-new-home-built-ingot-maker&highlight=smelter

[ftut]

Thats real nice Jim. I like the idea of the heat shield around it. Does it help that much with conserving heat? I might try something like that if you still think its worthwhile. I do have a question about your valve. What holds it closed? I was going to put a thread at the top of mine to open and close the valve. Yours looks like its only gravity holding it closed. Any suggestions for me before I get started?

[shadowcaster]

55567

This bottom pour pot that I built is only 4 1/2 inches deep, but it is 17 inches across. I think that there is a point to where you can be too wide or too narrow, or.. too tall or too short. I felt that I needed to have the ability and the room to add more lead, scoop, stir, flux, and flux again, and to accomplish this I needed a wider pot. I also made sure that I had a good heat source to handle this operation. I kept my depth at 4 1/2 inches so my thermometers would sit right and I would not exceed what my burner would hold weight wise (although I did beef up the burner). 1 gallon of molten lead weighs in at 95 pounds. My pot holds 4 gallons.

IMO.. 9 inches across is not very big (wider is more stable and easier to use) and may become top heavy if you make it too tall. The heavier your material is (you said 1/2 inch thick) the longer it will take to heat up because you have to bring the pot up to temp too. I would suggest using a rim or piece of well casing instead, and save the cylinder for other projects.


Here's the link to my whole setup..

http://castboolits.gunloads.com/showthread.php?t=146065

Good luck... :)

Shad

[shadowcaster]

Jim...
Hey, excellent job on your smelting rig. :) I didn't see it until today.

Shad..

[Jim Flinchbaugh]

ftut,
I used a pipe reducer bushing for the valve seat. Machined a small taper on the inside.
The valve rod has a long taper machined on the end so when its down, it interferes and makes the seal.
the valve rod is 1/2 inch, it has some weight, I put the extra chunk of steel on top of it to make it heavier.
After some lapping it works pretty good.
Make you nozzle, where the lead will exit the pot, as short and as close to the pot as you can and
still fill ingot molds. Mines kinda long, and I thought the valve was leaking for a while, but it just the 5-6 inches of pipe "running out"
of lead after I close the valve. It tends to make a small hill on the last ingot. I've been thinking about redoing the top of the valve to
incorporate a spring and make it work more like a bottom pour casting furnace.

The heat shield does help, especially if you have a breeze.

[454PB]

Assuming an I.D. of 8 1/2", your container will hold 23.23 pounds of lead per inch in depth.

[blikseme300]

What band heaters did you use? I've looked at several sights. Lots of choices!
What wattage is necessary?

The more watt per square inch the better as this helps quick heat up and stabilize the melt temperature when adding ingots. I can't recall the value but I calculated the wattage per square that a number of commercial units use and realized why they are better at getting to casting temps and keeping it there. My units have 2420w and can keep 70lbs of melt stable at whatever temps I choose.

It is important when choosing bands to be aware of their maximum operating temperatures as some have high wattage but low operating temperatures. Pipe and mold warmers are not suited for use in a melting setup. These bands can be quite pricy and I recommend searching on evil bay as surplus units are much cheaper. I recently found 4 more bands such as those I used before to make 2 more units at $15 each. Be patient and keep a watch out.


Bliksem
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[blikseme300]

I was thinking I would drill and tap a 1/4 pipe thread in the bottom and use a 1/4 pipe x 3/8 tube stainless steel fitting with a short 3/8 tube. the tube wouldn't have to be over 4 inches long and would run down beside my burner. Then with a valve inside very similar to what Bliksem did with his I would have a bottom pour pot. I wasn't concidering casting from this pot, only smelting ww down to ingots. Would I have to be greatly concerned with the temperature just to smelt scrap?

I use my PID even when doing scrap and set at 700. The reason I do this is to prevent melting any zinc or Babbitt alloys into my melt.


Bliksem
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[David2011]

Ftut,

Welcome to the forum!

Hiram has a great point about the depth not exceeding the length of your ladle.

Keep in mind that molten straight lead weighs about 94 pounds per gallon and marginally less with tin and other metals mixed in. You may also want to consider how much energy it will take just to heat a 1/2" thick pot to 700 degrees, even without lead in it. As the pot and its stand heat up the strength of the stand will diminish. Please consider all of this before going too big and heavy.

A thinner pot will absorb less heat and pass more on to the contents. Maybe you could fabricate something only 1/4" thick or so. It would still serve you for a long time.

David

[zuke]

As long as you keep the rest of the cylender you can make it as tall as you wish.
If you make it too tall take some off. If it's too short weld som on.

[jmsj]

ftut,
Welcome to castboolits!
Here is a link to one I did a while back http://castboolits.gunloads.com/showthread.php?84710-foot-pedal-operated-smelter-second-try
It is kind of tough to get the clips out sometimes if you don't take the clips out periodically as you go. Here is the method I use. I fill the pot completely with WW's and let them melt down and remove the clips, add more WW's to the top, let them melt down and remove those clips, I do this until the pot has just enough room for me to flux the melt
If I had to do this all over again I think I would use a shorter pipe but one with a larger diameter to make removing the clips easier. I'm going to modify the top of the base of the stand of this one so that the flames can travel up the sides of the pot with a shield around the pot. This modification should speed up the melt by heating the sides of the pot as well as the bottom and protect me from the flames.
There are lots of good ideas here on the site. Try out the search function.
Good luck, jmsj