DIY bottom pour pot finished, capacity 60lb :)

bertn

bertn

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First of all: many thanks to Yomomma for some advice and pics of the build of his pot.

Still waiting for my RPAL application to be processed so time to MacGuyver some equipment!
So much more to build that"s on my list (large WW melting pot, SS tumbler, bullet and case feeder,
annealer, lead harness tester) but hey, one thing at a time !

Well here it is:

28FBD.jpg


Pot itself started life as a fire extinguisher. (Old CO2 one with very thick wall)
It's heated by a coil heating element from a stovetop that I managed to straighten out
and wrap around the pot.

Still need to work on the spring tension of the bottom valve. The water test went fine without
the outer shell around the pot but after I put that on my valve raised a bit and now it's leaking.
Pot is still super hot from my test pour (melting some pewter items into mini cupcake molds)
so have to wait till it is cooled down for the adjustments.

It's quite large, about 6 inch diameter inside and about 6.5 inch high inside so about
a 60 lbs capacity LOL
Sure did not take long for the pewter to melt.

Now on the hunt for the right PID temp controler.
Any advise brand/model on this??
What kind of relay do I need?
Seen some on Amazon.ca at a decent price.

Cheers, Bert
 
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SSR size will totally depend on current of coil. Any PID controller from Amazon will do. With shipping times involved buy two and 3-4 thermo couples.

Make sure your thermocouples are rated at leas 1000°F.

Nice job.
 
yomomma said:
SSR size will totally depend on current of coil. Any PID controller from Amazon will do. With shipping times involved buy two and 3-4 thermo couples.

Make sure your thermocouples are rated at leas 1000°F.

Nice job.
Click to expand...

Thanks!

Don't know the current of my coil since it was not labeled (got it used from the re-store) and I also trimmed the heating element shorter because it wasn't getting as hot as I wanted it.
Do the pid and thermocouple break often? (Hence buying more than one)
 
bertn said:
Thanks!

Don't know the current of my coil since it was not labeled (got it used from the re-store) and I also trimmed the heating element shorter because it wasn't getting as hot as I wanted it.
Do the pid and thermocouple break often? (Hence buying more than one)
Click to expand...

Sometimes units arrive not working or wrong unit all together CYA

Worst case, sell the extras on the EE
 
GreenBob said:
Job well done! Let see it in action... video time? :)
Click to expand...

Don't know about that yet. One day.

Update: I adjusted the valve spring and its working perfect now. No leaks at all, just a few small drips from the grease nipple after closing.
The PID, SSR with heatsink and thermocouples have been ordered. Will take weeks to get here since it has to come from the other end of the planet.

Did the second batch of pewter melting and in about 15-20 minutes the pot made soup out of a few tankards, a plate, a piggy bank and some other pewter bits and pieces.
I also put 3 picture frames in but they had some sort of coating on it. Man what a mess in the pot...
Also need to work on an exhaust, my wife started screaming from inside the house what the h3ll I was doing in the garage...since half the house smelled terrible :(

After the disappointment of no video hereby a few pics of the pot in the making.
Yeah, I know my welding skills suck...

28FBU.jpg


28FBT.jpg


28FBF.jpg


28FBG.jpg


28FBZ.jpg


28FBV.jpg
 
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I can't figure out how your valve works, is the rod plugging a hole in the bottom of the pot? Also if I were to try to make my own what would be better stainless steel or regular steel? And would thicker walls be better? How hard was it to straighten the coil?
 
Belzebuth666 said:
I can't figure out how your valve works, is the rod plugging a hole in the bottom of the pot? Also if I were to try to make my own what would be better stainless steel or regular steel? And would thicker walls be better? How hard was it to straighten the coil?
Click to expand...

Valve...think sharpened pencil in a hole, stainless doesnt really matter as far as I know, toaster oven coils bend pretty easy.
 
Belzebuth666 said:
I can't figure out how your valve works, is the rod plugging a hole in the bottom of the pot? Also if I were to try to make my own what would be better stainless steel or regular steel? And would thicker walls be better? How hard was it to straighten the coil?
Click to expand...

Instead of making a tapered point on the rod I welded a bearing ball at the end.
Drilled the hole in the pot and stuck my dremel with a round grinding bit in the hole to make a good seat for the bearing ball.
(Not pretending it was my idea; got this idea from the piston pump of my Graco paint sprayer)

I would not use stainless since it is a lot harder to cut and more expensive. Your pot will be inside so it will not rust anyways.
Got the fire extinguisher for free. My local fire safety business had about 50 old extinguishers that they were going to scrap.
I took the one with a thick wall.
If I had to do it again I would probably go with 4 inch pipe though since I don't think I will need this much capacity LOL

Straightening the coil was not hard actually. But when I got closer to the center it snapped.
That was fine since I had to make it even shorter to get a bit more heat.
New heating elements bend very easily.
I would recommend a 110v toaster oven element like Yomomma mentioned.
It was a bit of work to reconnect and insulate the nichrome wire from the shortened element.

The nice thing about the straightened coil element is that it has a flat side so more contact area against the pot wall.
 
Just a couple of pointer gleamed from experience and castboolits.

I had my first coil short out on me because I did not factor in the amount the coil wants to "grow". I went in and opened up all the tabs holding the coil. Mind you mine was a toaster oven element.

Some people have experienced welds cracking from repeated heating/cooling sequences. I built mine so the outer shell extends past the bottom of the pot to correct any accidents down. Mounted the pot on a 18*18 piece of aluminum with 1" aluminum angle on three sides, back open. Should my pot ever crack most of the lead will be directed down and back I hope. Hoping my system at least gives me that second or two needed to step back and avoid any major trauma.
 
Sounds like you may have fixed the leaking spout with a heavier spring but I have 2 commercial pots and the valves are kept closed by the weight of the handle. The handle/valve is set up like a 2nd class lever rather than a 1st class. That said I still have leakage from time to time. I find it worse when the melt is cooler. It usually helps for me to heat it up to 800* and give it a good "flush" to remove the dross or whatever it is that is causing the leak.
 
yomomma said:
Just a couple of pointer gleamed from experience and castboolits.

I had my first coil short out on me because I did not factor in the amount the coil wants to "grow". I went in and opened up all the tabs holding the coil. Mind you mine was a toaster oven element.

Some people have experienced welds cracking from repeated heating/cooling sequences. I built mine so the outer shell extends past
the bottom of the pot to correct any accidents down. Mounted the pot on a 18*18 piece of aluminum with 1" aluminum angle on three sides, back open. Should my pot ever crack most of the lead will be directed down and back I hope. Hoping my system at least gives me that second or two needed to step back and avoid any major trauma.
Click to expand...

I would think (hope..) that if a weld fails it will trickle out first instead of a complete bottom out at once.
My outer shell extends past the bottom also. In post 8, second picture you see 3 nuts welded to the bottom. I screwed a round piece of hardie fibre cement board plus a thin layer of Roxul to the nuts at the bottom before wrapping it with outer shell.
 
pjs said:
Sounds like you may have fixed the leaking spout with a heavier spring but I have 2 commercial pots and the valves are kept closed by the weight of the handle. The handle/valve is set up like a 2nd class lever rather than a 1st class. That said I still have leakage from time to time. I find it worse when the melt is cooler. It usually helps for me to heat it up to 800* and give it a good "flush" to remove the dross or whatever it is that is causing the leak.
Click to expand...

I did not put a heavier spring in, it was just that the first time I drilled the hole (for the spring retaining pin) in the rod too low so the rod could not move down as far as it needed to seal it off.
 
Belzebuth666 said:
Does it get warm enough to melt lead too or it's only for pewter? Does it plug into a 110 outlet?
Click to expand...

It does get hot enough to melt lead. Just 110v.
Still need to make my big gas fired wheel weight melting pot to melt dirty ww lead into nice and clean ingots so that's why I only melted my pewter items.
 
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