I bought a harbor freight paint pressure pot and converted it to a pressure pot for resin. However, I am getting a slow air leak from one of the threaded connections. I used teflon plumbers tape, and some pipe joint compound but an still getting a slow leak. Any advice on a different compound to make a threaded connection air-tight?
1 Like
Can you advise which connection is leaking? I have found their built in pressure regulators to be garbage so I removed that on mine and set the output on my air compressor at 50psi. that stopped any last little leakage I had. also you have to make sure to ratchet down the lock screws like you were trying to break diamonds or you could get a slight leak from the lid.
3 Likes
First step is to find where specifically the leak is coming from. It may just be a faulty fitting, which I suspect it is because teflon tape is usually all you need for sealing an NPT joint airtight.
1 Like
You need to know what style fittings you have. There are straight threads which will thread all the way in. Those seal with an O-ring. Then there is NPT, then BSP, those are tapered.
4 Likes
I would bet it’s this. https://www.harborfreight.com/2-1-2-half-gallon-pressure-paint-tank-66839.html
In which case it’s standard NPT fittings.
If I had to guess, @Lordrook is right. Cheap regulators are leaky little bastards as a rule and you could probably solve it by replacing with a plug.
2 Likes
It is coming out of the regulator. I will use a plug and set the output to 50psi as Lordrook recommended. Thanks for the idea. As soon as I get this figured out am going to buy that harbor freight mini-lathe and make some more eggs.
4 Likes
Look to see if the 20% off coupons can be used on the lathe.
1 Like
Harbor Freight discontinued the use of coupons on power tool purchases. Still good for most other things in the store.
2 Likes
Soapy water can help isolate the leak.
Did you put three wraps of Teflon tape? Did you wrap it “with” the threads, so the flap end is pushed flat by the rotating attachment (clockwise looking from the end of the male part)?
2 Likes
Sometimes it just takes removing and reapplying the teflon. Make sure the threads are clean on both male and female sides.
I had the same problem setting mine up but after isolating with soapy water and refitting it has worked fine.
2 Likes
It is also worth noting that with all tapered fitting properly torquing them down is critical.
Lots of good answers here. Food for thought: used to work with composites where bag integrity was critical. We’d do a 60 minute leak down test to make sure the vacuum bags didn’t leak. We assumed that all gauges and regulators were junk and specifically had them built with 1/4 turn ball valves to make sure we could isolate them from the bags.
2 Likes
Good idea Ian, with a ball valve I can still use the pressure gauge quickly to get pot filled correctly, then isolate it with the ball valve.
Upgrade to a proper gauge instead of the one on the regulator, while you’re at it. Most cheap regulator gauges develop horrendous drift. Home Depot and Lowes both sell NPT gauges that will fit.
1 Like