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  1. RPF Premium Member cavx's Avatar
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    1 Week Ago  Sep 12, 2017, 4:34 AM - Help with Pressure Pot #1

    My pressure pot arrived today and I am hoping some pressure experts may be able to chime in and help.

    To say that the instructions were vague would be an understatement. I do understand the basics, but have no idea about setting the safety (pressure pop off valve) or if I need thread tape or lock tight on the threads to seal.



    I want to replace the 90 elbow with a straight ball valve (facing up so it never gets in the way of the clamps) for pressure reduction and guess I just need a cap on one end of the tee. I removed the inlet and safety valve so i would not damage them whilst getting this elbow off, but it would not budge. Do I need lock tight and how tight is the correct tightness. Before I removed it, I found it to be in the way of the clamps. I have since repositioned it out tof the way, allowing fast clamp down. My fear is that if I don't seal properly, I am going to hear a loud hiss.



    And I need to remove this part from inside the lid. It won't turn, even with Vice Grips. It was suggested that heating the part will soften the locktight used on the threads. Can someone 2nd that?


    Any help is appreciated.
    Last edited by cavx; 1 Week Ago at 4:45 AM.
  2. The Lone Wanderer RPF Premium Member GhostMinion's Avatar
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    1 Week Ago  Sep 12, 2017, 7:48 AM - Re: Help with Pressure Pot #2

    Alright, first.

    I use JB Weld as my 'loctite'. Stuff is great, and it can be removed later if the area is heated with a propane torch (ask me how I know). Just go as tight as you can get it without going nuts. The JB Weld will seal it, so no need to overtighten.

    I removed the safety valve on my two pots, but I don't leave them hooked up to the compressor. I fill them and then disconnect them. Most would agree that you should have them, but the ones that come with the pots release at lower psi than you want. I fill mine up to 70 psi, so I'd need to buy a safety valve that was rated for that or more. You can buy better ones, I can't remember where but it came up fairly quick in Google I believe.

    I had to cut that stem outta mine. Could never get it to loosen, even with heat. I cut it with a cutting wheel then grinded it down. Had to do it that way on both my pots.


    Also, on a side note. That type of pot scares the hell outta me. I had one long ago, and eventually the lid starts to get warped up from the clamps repeatedly sinking into it. I read once, here on the boards in fact, where a guy had the lid pop off and it coulda killed him, but he was lucky. In all fairness though, he had modified the can in an unwise fashion, but still. Ever since I saw that post, the one that I had scared me. I eventually lost my nerve, and bought the Grizzly can.

    Just be mindful of that and be careful. When it gets to the end of it's life, replace it.
  3. RPF Premium Member cavx's Avatar
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    1 Week Ago  Sep 12, 2017, 5:23 PM - Re: Help with Pressure Pot #3

    Thank you for replying.

    GhostMinion said: View Post
    Alright, first.

    I use JB Weld as my 'loctite'. Stuff is great, and it can be removed later if the area is heated with a propane torch (ask me how I know). Just go as tight as you can get it without going nuts. The JB Weld will seal it, so no need to overtighten.
    Will have to look for this stuff. Not sure what we have in the local hardware. If I can't find JB weld, is Locktight OK? Cause I can get lots of that.

    I removed the safety valve on my two pots, but I don't leave them hooked up to the compressor. I fill them and then disconnect them. Most would agree that you should have them, but the ones that come with the pots release at lower psi than you want. I fill mine up to 70 psi, so I'd need to buy a safety valve that was rated for that or more. You can buy better ones, I can't remember where but it came up fairly quick in Google I believe.
    This was my train of thought as well. The idea for me is to load them up and disconnect and ideally (in the future), I would have two or more pots on the go.
    My pot's rating is 58PSI. The gauge is in both PSI and BAR where it seems 1 BAR = 1 Atmosphere or 14.7PSI and 4 bar is 58.8PSI. Based on what I see when I degass and repressurized, if i can can get between 30 to 50 PSI, I am good.

    I had to cut that stem outta mine. Could never get it to loosen, even with heat. I cut it with a cutting wheel then grinded it down. Had to do it that way on both my pots.
    Based on what I found with mine, cutting might just be easier.


    Also, on a side note. That type of pot scares the hell outta me. I had one long ago, and eventually the lid starts to get warped up from the clamps repeatedly sinking into it. I read once, here on the boards in fact, where a guy had the lid pop off and it coulda killed him, but he was lucky. In all fairness though, he had modified the can in an unwise fashion, but still. Ever since I saw that post, the one that I had scared me. I eventually lost my nerve, and bought the Grizzly can.

    Just be mindful of that and be careful. When it gets to the end of it's life, replace it.
    I hear you loud and clear. This thing cost me $132AUD delivered, so if and when it needs replacing, not a huge loss.
  4. RPF Premium Member
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    1 Week Ago  Sep 12, 2017, 10:28 PM - Re: Help with Pressure Pot #4

    I am using the Harbor Freight paint pot that is so easy to get in the US.

    I used white teflon tape to help seal up the threads. I have been using it for years and have not had any problems with leaky threads.

    I had trouble getting the elbow off of mine too. I ended up leaving it there and attaching a quick release coupler. I put a pressure gauge in it to get a better idea of what the pressure is instead of just trusting my air compressor. I added some lines on the lid and pot to make it easier to always realize where I want the lid to line up so the elbow does not get in the way of the clamps.

    The safety valve that came with mine was really bad. The pot is rated for 80 PSI and the safety would blow between 20 and 30 so I took it off. I bought a 75 PSI safety valve at a local hardware store but I never got around to installing...I know I should. Before I charge the pot I make sure my compressor is fully charged and powered off. The loud noise of the compressor tripping on always startles me. I set the regulator on my compressor to 50 PSI and I shut the ball valve when the pot is charged and then disconnect the air hose.

    I replaced the clamp wingnuts with hex bolts so I can use a ratchet to quickly tighten them. People say the trick is to finger tighten the wingnuts and let the pressure blow the seal into place. That has not been my experience. If I don't get them tight I always have leaks. Speaking of which, when I have a leak it is not loud, but it is easy to hear if the compressor is not running and I will notice the pressure drop on the gauge.

    I attached a stainless steel scrubber to the inlet port to diffuse the air to avoid blowing resin or tipping over a small mold.

    I always make sure to wear eye protection and put a piece of plywood between my body and the pot while it is charging. I am aware of the blowing the lid off story referenced above but that guy had some major modifications on top of way over pressurizing the pot



  5. Member Since
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    1 Week Ago  Sep 12, 2017, 10:35 PM - Re: Help with Pressure Pot #5

    G'day, you can get JB Weld at Jaycar, if there's a store near you.

    Sent from my SM-G900I using Tapatalk
  6. RPF Premium Member cavx's Avatar
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    1 Week Ago  Sep 13, 2017, 2:32 AM - Re: Help with Pressure Pot #6

    McFlyte said: View Post
    G'day, you can get JB Weld at Jaycar, if there's a store near you.

    Sent from my SM-G900I using Tapatalk
    Jaycar is close and one place i would not even considered looking. Thank you.
  7. RPF Premium Member cavx's Avatar
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    1 Week Ago  Sep 13, 2017, 2:40 AM - Re: Help with Pressure Pot #7

    @sjanish cool set up. I guess your steel wool idea is what the regulator would do on mine?

    I added filters to my vacuum degassing system and they have helped with steadying the air rush in.
  8. RPF Premium Member
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    1 Week Ago  Sep 13, 2017, 8:20 AM - Re: Help with Pressure Pot #8

    cavx said: View Post
    @sjanish cool set up. I guess your steel wool idea is what the regulator would do on mine?

    I added filters to my vacuum degassing system and they have helped with steadying the air rush in.
    The steel scrubber isn't a regulator at all. A regulator lets you set and control the pressure level. When I pressurize the pot the air is blasting in at 50 PSI. The scrubber diffuses it so it isn't just shooting straight down in one stream. I don't want it to knock over my molds or blow still liquid resin out of them.

    I also used one, from the same 3 pack, to make a filter for my vac pump exhaust. The third one I use when I release the vacuum on the vac chamber. One time I had degassed some RTV and noticed a fine film of garage dust on the surface. I put the scrubber over the tip of my ball valve and it keeps the dust from getting sucked in.
    Last edited by sjanish; 1 Week Ago at 8:28 AM.
  9. The Lone Wanderer RPF Premium Member GhostMinion's Avatar
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    1 Week Ago  Sep 13, 2017, 1:24 PM - Re: Help with Pressure Pot #9

    sjanish said: View Post


    I am aware of the blowing the lid off story referenced above but that guy had some major modifications on top of way over pressurizing the pot.......


    Yes, yes he did. And not saying it will happen with an unmodified pot either. It's just ever since I read that story, it gave me the shakes. I would literally duck when I began to pressurize it.
  10. Member Since
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    1 Week Ago  Sep 13, 2017, 10:19 PM - Re: Help with Pressure Pot #10

    cavx said: View Post
    Jaycar is close and one place i would not even considered looking. Thank you.
    No worries. My brother uses JB Weld all the time. This guy even made a cylinder head out of it, to demonstrate it's capability (off-topic, sorry).

    Looking forward to see what comes out of the pressure pot!
  11. RPF Premium Member cavx's Avatar
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    1 Week Ago  Sep 14, 2017, 5:09 AM - Re: Help with Pressure Pot #11

    McFlyte said: View Post
    No worries. My brother uses JB Weld all the time. This guy even made a cylinder head out of it, to demonstrate it's capability (off-topic, sorry).
    Looks like Bunnings sell JB weld as well. Looks like a putty version of epoxy.

    quote]Looking forward to see what comes out of the pressure pot![/QUOTE]

    All things small that tend to trap air.

    I poured 2 small parts the other day. I gently massaged the molds and one always seems to trap air. 3 small bubbles which of course leave small holes on the surface. I guess I should have used a syringe to inject the resin. I am hoping pressure will help here.

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