Help, my pressure pot sucks.

Hello all,

I saw some threads that touched on this, but I need some help.

I'm trying to use the 2.5g paint pot from Harbor Freight to pressure cast resin parts. After setting up the air compressor and pot for a few hours (because parts either broke or didn't fit) I finally was able to try and test the PSI in the pot. I've read that for the best results, I'd need to be around 50 or 60 PSI.

The pot is rated between 30 and 60 psi, but when the gauge reads about 40 PSI, the safety valve opens and doesn't close until the PSI drops to 20. I've turned the t-handle control on the regulator both clockwise and counter clockwise and I can adjust it lower, but not matter what I do, once it hits 40 the valve opens.

Has anyone ever had this problem? I called Harbor Freight but their solution was just to offer me a replacement instead of a fix. I'm afraid that if it's replaced, it'll simply do the same thing again.

I cant afford the more expensive versions from Alumalite or other companies, so if anyone can help make this pressure pot work, I'd be grateful.

Is the pressure pot for casting resin, or do you use it to cure silicone for molds?

Regardless of what the pot is rated, it's likely a 40 PSI MAX switch for safety, there is likely nothing wrong with it to fix...

Replace the 40 PSI safety valve with a 60 PSI one... Or remove it entirely if you have other regulation and safety features implemented so you don't have a catastrophe...

New 1/4" air compressor safety relief valve 60 psi - eBay (item 170552315363 end time Feb-10-11 09:37:53 PST)

I have the same one and it does the same thing. Its a safety thing I think. You could install a higher rated release valve. Ive already considered that as well.
But for what I am casting it works fine. You dont need to be at the 50-60 mark for most of the resins out there. The 40 works fine.

Thanks for the advice.

I'm using it for plastic urethane resin. The instruction manual says it's rated at 80 psi, but I've heard some horror stories about Harbor Freight pots. I'm afraid to put 50 psi in it because I don't want it to explode.

Anyone have a sweet setup for their castings to help keep the lid from killing them?

Those Harbor Freight pots aren't very strong and I would assume that it has a 40 psi safety valve for a very good reason. But it's really a non issue anyway since 40 psi is plenty to pressurize resin.

Run a couple of casts in it and you'll see that it works just fine.