How to Find and Fix Air Leaks in a Pressure Pot for Resin Casting 

I bought my CA pressure pot from Finish Systems mostly based on your recommendations. I also had a small leak at the valve where the pick up tube would be if it were a paint pot and not a casting pot. I tried Teflon tape and joint compound with no luck. Finally I gave Finish Systems a call, they immediately apologized and offered to either replace the lid or send me some Loctite and a nut to thread from the bottom. I had them send me the loctite and it arrived in two days. I put a little on the threads, screwed it in, let it sit overnight, and it doesn't leak anymore. I just wanted to thank you for recommending Finish Systems, and let everyone else know that they turned out to be a great company to work with and that I'd highly recommend them.

When I bought my Harbor Freight Pressure Pot I had similar leakage problems. I realized the main leak was coming from the regulator that came with the Harbor Freight Pressure Tank. I took some soapy water in a spray bottle I found a crack around one of the threaded fitting holes. I bought a new regulator for a compressor and changed it out. I then found pressure leaking out from the lid. No matter how much I tightened the screws down, it still leaked. I was watching Chris Notap video on leaks and he told of a video he watched with the same problem and it was solved by turning the rubber gasket over that sits in the lid. The rubber gasket is flat on one side and has some grooves in the other side. The flat part gets laid against the top of the lid. The grooved side sits against the top of the tank. I use Vaseline to coat the edge of the tank and also against the rubber gasket. Last night I wanted to try it out. I pressured the tank using hand tightening the hand screws and not over tightening them. The tank didn’t lose any pressure at all over 16.5 hours! I was happily surprised with the results! I got a great deal on this Harbor Freight Pressure Pot. It was a display model with some scratches and evidence of tightening the screws around the lid. The manager sold it to me for $50.00 because it was his last pot and didn’t know if he would get any other pressure pots. Good deal even with purchasing the needed retrofit of the lid and the new regulator. Best regards, Richard

Putting together a 5 gal CA pot. This video was VERY helpful!! Saved me a lot of time getting it sealed up. Greatly appreciated! Thanks.

These are so helpful! Thank you! About the Teflon tape, I heard there is a thicker one that doesn’t degrade like the normal stuff. It’s meant for use with natural gas fittings. That might work pretty well for your use as well!

Great tips Zac! Thanks for what you do and for sharing it with us.

Zac, great info thanks. I need to get some 545 now! Keep up the great videos.

Thanks for this video - super helpful tips, much appreciated!

Zac -- I love it when you talk technical. So that's what causes a "wanky" lid?! Great job and good use of everyday words to convey a technical message. The correct terms most likely would have been over my head.

Thank you again for the great tips! I used the soapy water tip on my pot and fixed all of the little leaks that were making my life miserable :) I used Pipe Thread Sealant to seal the fittings, and it worked great. No issues at all now!

THANK YOU ZAC Loctite 545 works great!

Search Results I was always told that Vaseline or other petroleum products should never be used on rubber or neoprene objects. It can deteriorate the rubber or neoprene very rapidly. The correct lube to use is a silicone based lubricant. Using Vaseline on "rubber" parts is old school, may have been fine 50 years ago even 30 but today "rubber" is made from all kinds of synthetics.

My 545 came in today. Thanks for the info.

Another great video Zac, the pressure pot I’m getting is purpose built and fully tested so hopefully I won’t have any issues, but I will know what to do if I get any problems. Cheers, Jim

my relief valve is in the same spot as yours and after trying everything I used JB weld..no more leak.. who says you can't kill a fly with a hammer

It is good to share 101 info with the newbies.

Awsome tips. Cheers! From Perth Australia.

does loctite blue 243 work the same in sealing air?

Love and appreciate your tutorials. I could use some further advice. I used the product you recommended for sealing threads but after tightening down solid and waiting 3 days my pressure release valve still has a leak. It's not popping open, I made the adjustments for that. It's just slowly leaking air. It is a harbor freight 2.5 gallon paint pot and that seems to be my only problem at this point. Any suggestions?

Thanks great info . just managed solved my problem using your method . no more leaks .

I’m getting leaks around the T-handle on the regulator itself- any recommendations for how to fix that? Is the best way to just get a new regulator?

Nice video, you explained the process very well.

I tried a small amount of clear silicon and will check it tomorrow when it dries if not Vaseline is next! Thx for the tips

Hi Zac. I really appreciate these videos. If you don't mind, I do have a question for you. I found a leak in one of the factory fittings. But it's stuck in there so that I'm still not able to get it off. Do you have any advice for something I can put on the outside to seal the leak? Or of a way that I would be able to remove the fitting.

Very helpful, thank you

what kind of fitting are you using to put the pressure valve on the top of the pot. Seems to be 2 different types of thread and i can't seem to find one. Thanks for the good video

Hi Zac! Amazing video :) Do you think Loctite 542 would work also ?

Nice video and good tips Zac.

Good info, Zac. I have a slow leak somewhere and I guess I'll look for it. Reason I haven't is because I haven't had to. cheers, Lee

Can't believe I didn't find this before, Zac. Great info and funny stuff, man. My two [forever fourth graders] 16yo's will have a blast with that.

zac awesome video mate 😉 love the bloopers at the end 👊

Good vid Zac. I bought a PP off ebay and it is a good brand with the hold down tabs for the screws made into the lid. So you only have 4 positions to turn the lid so it lines up with the bolts. I had problems with the seal leaking and even bought a new seal and still did not work. On a whim i took the seal out and put a small bead of silicone in the seal pocket and then put the seal back in. Gave it a few days to setup and then locked it down and put the pressure to it and now it seals and in any of the four positions. As the pressure builds I can hear the seal leak some between 25 and 30psi. Then i hear a slight thump and no more leak and will hold 45-50psi no prob. I can leave the PP sealed for several days with very little leak down. I may give the loctite 545 a try on my fittings as that may be where my very small leak is.

Would you ever use teflon tape and the Loctite 545 at the same time or just the 545 by itself?

I've checked all my plumbing and tried all the lid tricks. I even tighten with a tool to make sure. There is no sound coming from my pot or bubbles. But it still wont hold a PSI of 35ish for more than a few hours. There is a small dent out on the bottom rim could that be it? Very frustrating.

Thanks so much for this video! Exactly what i was looking for

Hi Zac, Some good tips there! One thing you forgot to mention, when you want to remove a fastener or fitting that has been sealed with Loctite, it removes easier when you heat up the fitting. Without heat the fitting is really hard to get off without damage. Hope that helps.

I noticed that you had a cap on the inside of pot. Where did you get that fitting? What size and thread was that? Thank you

I tried closing up the lid doing the screws on opposite sides but my problem is I have weakness in one of my hands because of pressure on a nerve that is still healing. But even before that accident I was getting leaks. Other times I have managed to get it to where the only leak I was getting was from the safety valve. That's what I want.

Ha Zac I have a question I got a vacunm PUMPr a few months ago used it maybe 5 time and already it froze up ,the question I have is two things 1. WHICH ONE WOULD YOU suggest? the other question is once the chamber gets to the right setting do you still let the pump run? thanks Larry

Instead of Vaseline, I used Dupond Teflon Silicone lubricant. The lid works perfect afterward. The lubricant helps prevent dust and corrosion as well. My pot stayed at 50psi without any leak after 24 hours. Other than the pot itself, I had to change every single pieces, including the regulator as well (it was leaking around the screws as well as the knobs). However, it is working great now. The price came out to be around $150. I might as well bought the other upgraded pot :(

Had a feeling the seal wasn't right. I locktite'd all the bits n bobs and had hit it was soap and no bubbles. Your vid showed only 1 other possibility so i'll rotae it the next few times I use it and hope i find a sweet spot. I swear i'm also tightening it enough but recently had nerve damage in my arms and lost a lot of strength so i wonder if i'm not tightening it enough too.

I found a small hole in the actual pressure pot itself very late in the process. Any tips for fixing that without a welder?

Great stuff, convert my pot Saturday and it lost pressure over the last 2 days. Will try your techniques to (hopefully) solve my leaking issue. Thanks from Down Under.

I'm having seal issues and would like to replace the seal on the Harbor Freight. Any suggestions on what seal to use?

can you use tape and loctite

The Vaseline trick has mostly worked for me - brand new at this and my pot previously got to ~20psi before the gasket leaked, now it'll get close to ~45psi before I hear the faintest "tsssss." The new leaks are right at a clamp, so a wrench on the wingnut makes the sound go away. Alumalite recommends 40psi for their resin so I won't push my luck with increasing pressure and restarting the leak. First casting's in there now, we'll see how it turns out!

what about RTV Rubber gasket maker?

Im Building a cannon and there leak air out there the metal pipe is skrew in the PP Pipe. How do i plug it?

I have a pressure pot that the meter stop working . Is there a easy fix or do I need to get a new on metter

Do you have a video showing how to replace the safety release valve on a CA Technologies tank? I just got mine and barely used it and now the damn safety release leaks as if it were just an open hole...its absurd. I have never replaced on, so not sure what part I need to loosen with a wrench...there are 2 nuts. I have placed an order for some Loctite 545 from amazon...

Do you have any problem with the safety valve? My safety valve is leaking at the ball inside the valve, that's very annoying

I have a Harbor Freight pot and the leak is around the weld not the fittings. Any suggestions?

Great info. I grew up in a small town named Rector.

Zack bought my first pot and the paint is chipped on the rim they want to take $50 dollar off should I just get another one thanks

I have used 2 kinds of Teflon tape, loctite thread locker, 2 part epoxy, gas rated duct tape, marine grade thread locker and out of desperation super glue, hot glue, caulk and Vaseline. My pot *still* won't stay pressurized! I did the soapy water trick and can't find any leaks. Any ideas?

I agree with everything you said, and was very helpful. However, using red loctite can be a problem if you ever have the need to replace one of the fittings. I’ve used the red loctite before and it’s near impossible to remove the fitting.

I have a leak coming from the lid, on the inner circle. From a weird weld thing the manufacturer did. It is slightly misaligned and The last two pots I purchased had these weird weld thing, so I am curious if this thread sealant could possibly aid in sealing up this gap. This gap is beside this rubber seal on the lid, from this weird weld thing> Honestly I want to salvage this pot to use for resin but I am scared to break this so seeking some community aid, much thanks

I'm having trouble finding pressure relief valves that are either rated for around 60 PSI or even state what PSI they are set for. In chasing leaks in my HF pot I cranked it down too hard on my valve and broke it and the tee it went into. In searching for replacements, all that I found were rated for 200 psi. I found one that I thought may work but got it yesterday and it too was 200 psi. I'll try to adjust it down, just hoping it goes down that low. Another tip if you are replacing the fittings, just go for black pipe fittings and try to stay away from brass. You can't break iron. :-)

How is my question about the Vaseline? Does it destroy the silicone apparently not thank you very much, sir.

helpful!

Love the vids Zac, am a newbie. My CA pressure pot looses like 1 pound pressure per hour? I have tried to fix any leaks but still a slight leak somewhere, how worrisome is the slight leak in casting? is there a "too low" pressure that will screw up the casting after 10 hours or so?

Great video. It happens that I'm having air leak problem. Will use these techniques today. Thank you.

you talked about finding and fixing the leaks of pressure pots. I just setup a harbor freight pot. I have never done any pressure casting before. I got all the plumbing sealed pretty good. used your soap suggestion. You suggested using petroleum jelly for around the seal of the lid. I have done this and it worked. However i had to reapply when I went to seal up the pot again. Does this mean that the gasket is bad? I tighten the lid across just like you said.

My CA Technologies pot was leaking bad from the fittings even after using Teflon tape. I bought some 545 and that stuff worked like magic. $26 for a tiny bottle, but well worth it.

Hi Zak just received my C A Tech Pressure Pot and i have a leak at the factory inlet fitting on the Pot lid , do you recommend any method to fix this or should i send it back. Thanks Roger

Hey Zac, I tried using teflon tape to fix an air leak on my cap for my regulator. After 3-4 attempts with multiple length of teflon and making sure that the cap is extra tight, I find that air is still leaking from the same spot. Do you know if this is an issue with the brass cap itself or should I just purchase the anaerobic sealer?

Zac, I love your videos!! After making a few banks with liquid diamonds without a pressure pot, I finally got one. As I tried it, it seems to leak from the regulator itlsef, that sort of t handle with a screw seems lo lose air. any tips on solving that? Thanks!!

I've been watching your videos pretty much non stop for the last week and love all the great tips and tricks. I just started casting my own pen blanks and have been trying something I have not seen in all my video searches and I would love your input on what you think. Is there a way I could send you some samples of what I've been putting in my castings for your opinion and if so what is s good size to make them for your pen blank mold. Thanks again!!

Since I just got a HF pressure pot I've realized a few things. Yes tape is not going to work well. The old HF fittings are glued in and leave residue in the threads. I used the proper sized pipe taps to clean them out. I don't think the lid threads are tapered so very little threads are used. The tap helped this a bit. I did use dope after getting leaks by using layers of tape. I used black pipe fittings instead of grass since you can tighten them down more. I also pretty much only used the pressure relief valve and plumbed up everything a little differently than yours.

Good info Zac. Found the link to the Loctite but not to Rectumseal. :-) You did say it worked?? JimE

First yea...great tips Zac...

I'm still having leakage from the lid itself after applying vasoline, I noticed the gasket is a flat, clear rubber instead of the one on your lid. Do you think buying a replacement gasket would help fix it?

i can only get my pressure pot up to like 10 psi before the air starts coming out the side no matter how tight i tighten the bolts. its a brand new pressure pot.

My new harbor freight won't go to 40psi without valve popping off.

What's old is new again. Same technique we'd have used as kids to check tire tube leaks, and the same tightening pattern used for ages to fasten wheels to hubs.

My regulator leaks SO bad. Idk how to get it to not. I can’t even get my pot to 40 psi 😭

Why not CA glue and accelerator? I have not desire of removing anything later. Always will be a pressure pot.

Lol That's an easy name to get wrong and it sounds really similar to rectum seal.

DON'T apply petroleum jelly to the gasket lid... PJ eats rubber. Use silicone oil/lubricant instead.

Petroleum jelly isn’t good for rubber just saying

WARNING - Petroleum jelly breaks down rubber.

Zac, great info thanks. I need to get some 545 now! Keep up the great videos.