Pressure pot still leaks

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bcoyne

Member
Joined
Apr 6, 2007
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40
Location
Lenexa, KS, USA.
I found a HF pot at a rummage sale for $10. Made my conversions to it and Replaced the rubber ring on top as it leaked with old one. It still leaks all the air out after about 3 hr. I put it under 40 psi and turned upside down and poured water around the seal. saw bubbles.

Any suggestions?
Thanks
 
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So despite all the warnings about HF pots you bought one anyway...at a garage sale no less??? Fix it yourself dude...
 
bcoyne said:
I found a HF pot at a rummage sale for $10. Made my conversions to it and Replaced the rubber ring on top as it leaked with old one. It still leaks all the air out after about 3 hr. I put it under 40 psi and turned upside down and poured water around the seal. saw bubbles.

Any suggestions?
Thanks
Click to expand...

I have two thoughts.

First, where did you get the new seal? Are you certain that it is the correct one for your pot?

Second, my pot leaks some. I don't know how much because it has never been a concern of mine. It's not so much that I can perceive it if I'm standing there. I keep the pot connected to my compressor tank overnight (compressor off). The regulator keeps it at the pressure that I selected.
 
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Are you casting alumilite? If so, 3 hours is more time than you need. And if you're casting PR, just leave the pressure hooked up with the valve open. And 6 hours is plenty for PR. The worst that could happen is that your compressor will kick on. But the pressure to the pot shouldn't change.
 
Mine does the same. Just keep the compressor hooked to it. Mine will totally leak out in three hours if I don't keep it hooked up.
 
My HF pot needs to have each clamp tightened in slow sequence. (i.e., 3 turns valve 1
#1; 3 turns valve #2, etc...). It will hold 40 PSI for up to 18 hrs. If I tighten one valve very tight, the opposite side will leak.

Hope this is a good suggestion.

FWIT: I use Alumilite at 40 PSI for typically 1 hr. with a HF pot. I DO not go above 40-45 PSI. (I have no need to go higher).
 
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Sure, the main rubber seal is always the first thing people think when the pot leaks but, if you have inserted the pot in water and you saw bubbles, you need to identify from where they are coming from as 50% of times, is not the seal leaking but, one or more of the connections on the lid that are leaking and to resolve the issue, you have to remove one fitting at the time, clean and put some white threaded tape and re-install..!

For the main seal, a dry one doesn't work as well as a lubricated one, Vaseline is a good product to use, but I use what I had in quantity and that is some leather lube, I use on new and used leather working boots to maintain the leather soft...!

Remove the seal and clean the aluminium and rubber with some acetone or Methylated Spirits then, spread a small amount on both sides of the rubber seal and put it in place, it should stay there, if is the right size. Make sure the lip/edge of the pot is wiped clean before putting the lid on. Tight the nuts in cross orientations, as you would do in a vehicle tyre, this should maintain an even pressure on all nuts, failing to do that, the pot will leak every time...!

I have made myself a small wooden handle (here @ post #54 to assist with tightening the nuts, my weeks wrists did need something to avoid further damage to them and the extra length allow me "feel" the pressure I'm exerting on each nut, in a more controllable/controlled way...!

Have a go and let us know...!

Cheers
George
 
BSea said:
The worst that could happen is that your compressor will kick on. But the pressure to the pot shouldn't change.
Click to expand...

Or the seal will blow out completely and the compressor will run all night. When I first started, I used to leave the air hooked up to the pot as suggested. I came in one morning and my compressor was running full on and smelled really hot. I walked into the shop and the air was blowing as if you were using an air gun. The gasket had blown out. Once I shut it down, the pot had a bunch of water in it and the next day, the compressor completely seized up and failed.
 
When I used my pot I left the compressor hooked up all night but turned the power off. Like mentioned earlier depending on the type of resin your using will determine the amount of time you need to keep the cast under pressure. I use P.R. so I always left it over night and checked it when I made it home after work the next day. With the volume of air in the tank there was plenty of pressure to let the resin set. I never left the compressor on because if a hose or something was to break causing it to start running and burn up the compressor.
 
MesquiteMan said:
BSea said:
The worst that could happen is that your compressor will kick on. But the pressure to the pot shouldn't change.
Click to expand...

Or the seal will blow out completely and the compressor will run all night. When I first started, I used to leave the air hooked up to the pot as suggested. I came in one morning and my compressor was running full on and smelled really hot. I walked into the shop and the air was blowing as if you were using an air gun. The gasket had blown out. Once I shut it down, the pot had a bunch of water in it and the next day, the compressor completely seized up and failed.
Click to expand...
Yeah, I guess that wouldn't be good.

For me, I'd probably know about it since my compressor is in my garage. But You're right about leaving it open all night. Not a good thing.
 
First clean the surfaces thoroughly. Very thoutroughly since it doesn't take very much to allow a tiny leak.

Then try coating the seal (gasket) with some silicone plumbers grease (the real silicone kind, that stuff that comes in little half ounce containers, not the petroleum kind.

If it's leaking down over 3 hours it isn't much of a leak and that silicone grease is thick enough to resist pressure on a very small leaking surface.
 
I don't know a HF Pressure Pot from a chamber pot. But I did have friend who forgot turn off the compressor in his store. Overnight the thing overheated, started a fire and gutted his shop. Not good.
 
This is why I turn off my compressor when I leave my pot hooked up over night. There's plenty of air in the compressor's tank to keep the pot's pressure up for as long as needed. There's no need for the compressor to run, at all.
 
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I don't even know where the off switch is on my compressor, seriously! It is hard wired into the breaker box so I guess I could flip the breaker if really needed.
 
At harbor freight you can by a tire filling attachment for $8. It has a trigger, a guage and a hose with a long metal piece on the end that you stick on the tire valve. You remove that tire piece off the end so you just have the hose, guage and trigger. That hose is already the right thread size on the end to fit your lid so just teflon tape and screw it in. Put a 50 cent quick connect on the other end, done. Now you just uncouple your airhose it wont leak, the trigger is a valve. You can use the trigger to remove the air from the pot too. Cheap fast easy.
 
Here, i took a photo. Its so simple, the pot conversion is $9 total, the tire filler guage, quick connect and a plug. Been using this system on all my pots for years. I set the tire filler piece i removed on the lid, it was on the end of the hose. Every piece that came with the pot except the pressure valve is in the trash can. Less parts is less chance for leaks. Attach air hose, squeeze trigger, guage tells the pressure, pop off the hose or not doesnt matter. After done squeeze trigger will release the air too.
 

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its already been mentioned but proper tightening of the lid is teh best way to get rid of seal leakage. I tighten opposite sides at the same time never going all the way tight before catching up the other two sides.
 
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