Last Try at Fixing Pressure Pot

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jkeithrussell

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Ok, here goes my last shot at getting a pressure pot set up. I've spent a ridiculous amount of time and money on two separate pots trying to get it to work. Leaks no matter what I do. Not from the fittings -- just a slow and steady drip of pressure. I have really enjoyed the limited amount of casting that I've been able to do during the brief periods of time when my pot holds pressure, but overall the whole exercise has been frustrating beyond description.

I've come to the conclusion that the gasket that comes with the Harbor Freight pot is garbage. Is there an available alternative? I thought about maybe filling in the slot with silicone rubber and just tossing the gasket, but don't know if it would work. I've looked every place I can think of to look but can't find a better gasket.

Any ideas?

Last question -- how much pressure is appropriate for the clamps? I turn them a little more than snug. I don't know if I should be screwing them down tighter. When I try that, the air blows out faster and the gasket twists around. When it's not tight enough, the air just whistles out.

Sorry for the rant -- I've purchased 2 pots and 4 sets of fittings and spent the better part of 3 weekends getting nowhere and I'm pretty disgusted with it.
 
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If no one here has a place where you can get a replacement gasket, then your idea of using silicone to 'make' a gasket should do the trick. Another gasket material to try would be one of the Permatex materials available at auto parts stores everywhere. Just allow whatever material you use to set up completely, and I mean completely otherwise you will just be gluing the lid to the pot.

A quicker solution might be to take this pot back and swap it for a new one, that is if you can put it back to it's original makeup.

It sounds to me though that you might as well go to the store and get a tube of material and make your own gasket. Less work, more fuss, but in the end it will all be worth the time and effort.

Good luck on all your endeavors ... Hang in there IT WILL GET BETTER! :biggrin:
 
I turned my HF pot's gasket upside down (removed and flipped). That has made a big difference for mine. Might give it a try.

Tom
 
The silicone should work fine . Permatex never really totally dries , it skins over , and takes a long time to do that . If you can get some casting silicone (the stuff used to make molds) that would work best . Just mix it up and pour it into the grove in the lid and let it cure for a day or two . It will make a totally seamless gasket .
 
I bought my HF pressure tank today, rigged it up and it leaked around the gasket. I had the clamps as tight as i could by hand, so I got my cresent wrench out and turned each clamp 1/4 turn and that was it. No more leaks. Hope this helps.

Mark Tupper
 
Mine leaked also. I mixed up some dish washing liquid with water and found the exact place ,and it was not any of my fittings ,as I used teflon on them but ,as in your case ,it was the gasket,looking around in the shop trying to find a fix I dipped my finger in motor oil and applied to gasket then wiped off any left with paper towel put lid on and tighted it down then turned it some more making a permanent indentation in the gasket. I don't know if the oil ,even if it was only on it less than a minute ,soften the gasket or not but it worked. 60 lbs and holding..
also mark your lid and pot so it goes on the same every time lid--- ---pot as there are 4 different ways to put the lid on. I was told this during a casting demo.
I use a cheater to tighten not just hand tight. I learned that at the same demo.
 
I have no experience with this particular pressure vessel; but do have experience with other types of pressure vessels. many of which have working pressures much higher than the HF paint pot.

First thing I would do is screw down a little more on the clamps and be sure that you tighten the clamps equally as best you can. Hand tight plus about a 1/4 turn should be about right. Tightening the clamps too tight can deform the gasket and actually exaggerate the leaking problem.

Next thing I would do is grease the gasket with a silicone grease. It may be a little hard to find; but is a much better material to use than motor oil or automotive grease.

And finally, I see the manual for the pot mentions that there is a "rubber" gasket available as an accessory that is to be used when spraying materials that are corrosive the the standard gasket. I don't know what the standard gasket is made out of; but suspect you might get a better seal with the rubber gasket.

Wish I had seen this post a bit earlier as I was just at HF yesterday and could have taken a closer look at the construction of the pot.
 
you might also try to tighten two of the wingnuts at the same time... the two across from each other, then the other side. My pot drops from 50 to 40 PSI over the hour to hour and a half i let it sit. If i were doing something more serious it might be an issue, but i have not hit any air bubbles yet, and i have turned at least 20 or 30 of my own blanks.


Greasing the gasket will probably make a big difference in your case. The silicone grease spoke of earlier is what i would get also. Auto parts stores and good speed shops should carry it. In fact, A decent speed shop would probably just grease the gasket for you if you took it with as opposed to selling you a tube or vat of grease for one little app.
 
Thanks for the tips. Does anyone have a specific recommendation for a silicone rubber product (2-part, like RTV?) that I can use to try to make a new seal?
 
My hubby uses Silicone Pool Grease. He says to grease both sides of the gasket. I was having the same problem and this seemed to fix it.
 
Second on the flipping the gasket and Silicone Grease.

I pulled my gasket out and VERY LIBERALY coated the entire thing with a "disc" of silicone grease I got at Lowe's (Plumbing Section) and put it back.

Another thing to try is to figure out where to put the lid in relation to the pot. Take a piece of tape and run the tape down the lid to the pot- then cut the tape at the joint (lines up the tape).

Now fill and check for leaks. If it leaks, depressurize, rotate the lid about 10-20degrees, and repressurize.

You will find a spot that leaks the least if at all (HF Pots are noted for being a bit OOR). Once you find that "sweet spot" Mark that spot on the lid and pot- that way you can always find your sweet spot evertime you lid up.

Doing these, I now lose about 4-5 PSI in 24hrs now.

Good luck!

-Doug
 
My HF pressure pot had the same problem. I found the best position for the lid then hooked the vacuum generator to it, I let it set with a vacuum on it until the next time I need it. I think it was about 2 weeks. Now I position the lid in the same position each time I use it and I have no problem with air leaks. I guess setting that long with vacuum help form the seal.
 
jkeithrussell said:
Thanks for the tips. Does anyone have a specific recommendation for a silicone rubber product (2-part, like RTV?) that I can use to try to make a new seal?
Click to expand...

If you want to make a gasket like Butch suggested you can go to polytek.com or smooth-on.com. There you can buy a small kit of tin-sil mold material. I would suggest you get at least a Hardness, Shore A of at least 25. If you use polytek they have a trial price for first time customers, I don't know about Smooth-on.

If you have questions send me a PM and I'll help the best I can.
JJ
 
smitty said:
My HF pressure pot had the same problem. I found the best position for the lid then hooked the vacuum generator to it, I let it set with a vacuum on it until the next time I need it. I think it was about 2 weeks. Now I position the lid in the same position each time I use it and I have no problem with air leaks. I guess setting that long with vacuum help form the seal.
Click to expand...

Now that you mention it, One of the thing I did that turned my HF pot around was to put the lid on, really crank it down (with 12" crescent wrench assist) and let it set for about 5 days. I have it marked for correct position also.

I have no problems holding pressure now.

May be on to something now.

Tom
 
jkeithrussell said:
Thanks for the tips. Does anyone have a specific recommendation for a silicone rubber product (2-part, like RTV?) that I can use to try to make a new seal?
Click to expand...

Ordinary rubber cement like school kids use should work.
For some water filters I had trouble with, I smeared the gaskets with petroleum jelly. Messy and needs replacing but is cheap and works.
 
You can find O rings that will fit it, locate a Bearing Belt and Chain industrial store they have O rings up to 3/8 diameter and I've got them up to 36 inch diameter, Also some auto supply stores make Neoprene O rings, You might try some independent auto supply stores, forget Autozone or the other chain stores, tractor repair places also usually can make O rings to size, or tell you where you can get them.
 
Allorings.com is a real good place to get o-rings as well as McMaster-carr.com check them out if all else fails
 
Keith,

Are you tightening the clamps equally like you would lug nuts? In other words, gently tighten the ones across from each other, then rotate to the others. Then come back and tighten more. Go all the way around and tighten as tight as you can by hand.

Other suggestions:
Add registration marks so you always go back to the same spot. When you first put on the lid, wiggle it back and forth just a little to make sure it is seated properly. Take the seal out and turn it over. Before re-installing it, coat it liberally with grease of some kind. Also double check to make sure your relief valve is not the culprit. Sometimes they will leak and you will not realize it.

I have purchased and set up 5 different HF pots and have not had one of them that I could not get to hold air with all of the standard equipment. I did have a Binks pot that I bought used that had a bad gasket and I did not want to try to find a new one. I took the old one out and carefully filled the recess with urethane sealant (in a tube like caulk) and smoothed it out. I then let it cure a few days and it worked fine. It was not as durable as the factory material, though, so it started leaking again after about a year of hard use.

If you still need help, shoot me a PM and I will build you one and send it to you just for the cost of materials and shipping.
 
MesquiteMan said:
Keith,

Are you tightening the clamps equally like you would lug nuts? In other words, gently tighten the ones across from each other, then rotate to the others. Then come back and tighten more. Go all the way around and tighten as tight as you can by hand.

Other suggestions:
Add registration marks so you always go back to the same spot. When you first put on the lid, wiggle it back and forth just a little to make sure it is seated properly. Take the seal out and turn it over. Before re-installing it, coat it liberally with grease of some kind. Also double check to make sure your relief valve is not the culprit. Sometimes they will leak and you will not realize it.

I have purchased and set up 5 different HF pots and have not had one of them that I could not get to hold air with all of the standard equipment. I did have a Binks pot that I bought used that had a bad gasket and I did not want to try to find a new one. I took the old one out and carefully filled the recess with urethane sealant (in a tube like caulk) and smoothed it out. I then let it cure a few days and it worked fine. It was not as durable as the factory material, though, so it started leaking again after about a year of hard use.

If you still need help, shoot me a PM and I will build you one and send it to you just for the cost of materials and shipping.
Click to expand...

Thank you! Very kind offer.

Let me continue to work through these suggestions. If I don't get it right pretty soon, I'll get in touch with you.

Thanks again.
 
What about just leaving it hooked up to an air compressor and set the regulator to where you want it?

Also, being in the Houston area, there are MANY places that will make custom gaskets for you. Try Roy Wright at Bay Area Gasket and Supply.
www.Bayareagasket.com . Their site is under construction but their phone number is on main page.
 
Bad idea leaving the hose hooked up. Couple of reasons...if the leak gets worse, you may come back in a few hours and find your compressor running full bore. In a couple of days you may find your compressor has burned up. I know this from experience, btw! My $500 compressor died 3 days after a seal blew out on a pot that I thought was not going to leak at all.
 
I lost a compressor under similar circumstances.....not casting, which I don't do.....but in a situation where the compressor ran for several days straight. Luckily, it was one of those $89 cheapies; but a loss nonetheless. I replaced it with another similar unit and that one has served me well now for a number of years. My use is fairly light duty: airing up the occasional bike or car tire, running a brad gun or air brush and blowing dust off my work bench. It would probably be a good idea to invest in a higher quality compressor if you plan to use it more than once or twice a week.

Heed Curtis' warning. It is probably a relatively uncommon occurrence; but no less painful if it happens specifically to you. :frown:
 
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