thewishman
Member
Going to today's HF sale and buy the pressure pot. There are so many pressure pot set-up ideas posted here, is there a simple one that a non-mechanically inclined guy like me can do it?
Is there a simple way to set up a HF pressure pot?
- Thread starter thewishman
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gketell
Local Chapter Leader
If you are doing pressure only, yes. Look on the back of the pressure gauge and you will see an arrow for "flow through" direction. Buy a plug and plug the "output" side. Buy a quick connect nipple for your air compressor and put it on the "input" side. Plug the paint output port. Done.
For bonus points get a 90-degree elbow and put it on the inside of the pot where the pressure regulator comes in.
To use: set your air compressor output to 70 pounds. unscrew the pressure regulator control on the pressure pot. hook your air compressor to your pressure pot. dial up the pressure regulator control on the pressure pot up to max it can take without leaking. (SLOWLY or you blow your resin out of your mold and all over your pot).
For bonus points get a 90-degree elbow and put it on the inside of the pot where the pressure regulator comes in.
To use: set your air compressor output to 70 pounds. unscrew the pressure regulator control on the pressure pot. hook your air compressor to your pressure pot. dial up the pressure regulator control on the pressure pot up to max it can take without leaking. (SLOWLY or you blow your resin out of your mold and all over your pot).
thewishman
Member
Greg, that sounds like a plan even I can follow, thanks!
workinforwood
Member
I always have problems with the stupid safety valve. I cut the tube under the lid. I plug that hole. put an elbow under the inlet to flow air to the side not straight down. I unscrew the safety valve and toss everything away. I buy a tire filler unit at HF, it is an $8 accessory, it has a squeeze trigger and a big round pressure indicator on it. You just unscrew the actual part that fills your tires, then screw that right into the pot..it's the same 3/8 size and threading..done. I dont think the tire accessory thing comes with a quick dissconnect, so you might need that to attach your air hose. To let the air out, just squeeze the trigger, same as putting air in.
rjwolfe3
Member
Chris,
If a bonehead like myself can figure it out, surely you can, lol.
If a bonehead like myself can figure it out, surely you can, lol.
wdcav1952
Activities Manager Emeritus
How true, how true!!!! :biggrin:
rjwolfe3
Member
Bleh!:tongue:
:biggrin:(At least I don't wear pink)
rherrell
Member
BigShed
Member
Like a previous poster, I eliminated the pressure relief valve altogether, I also eliminated the regulator.
I set the maximum pressure (my PP is rated at 80psi) on the compressor to 70psi, I set the air supply to the PP at 60psi. It will hold this pressure for at least 24 hrs, although I don't leave my casts in that long.
Also removed paint intake hose inside the lid,
Put shut off valve on air intake side so that I can shut the air off at the pressure I want, usually 60 psi
Final pot looks like this.
Note I also have a valve on the pressure gauge side, this is only because I couldn't find a suitable male plug! As a side benefit I can open both valves to release the pressure
I found I couldn't get a completely airtight pot without the use of this stuff, joint compound, now it will hold pressure "forever".
To overcome the "blowout" potential problem and increase the capacity of my PP, I made up a 3 tier rack for the moulds (Gadget's as well as some I made) the top diffuses the air flow very nicely, the handle allows me to put it in the pot and take it out very easily.
I have attached a more complete description in a tutorial I did for Australia's Woodwork Forum.
I set the maximum pressure (my PP is rated at 80psi) on the compressor to 70psi, I set the air supply to the PP at 60psi. It will hold this pressure for at least 24 hrs, although I don't leave my casts in that long.
Also removed paint intake hose inside the lid,
Put shut off valve on air intake side so that I can shut the air off at the pressure I want, usually 60 psi
Final pot looks like this.
Note I also have a valve on the pressure gauge side, this is only because I couldn't find a suitable male plug! As a side benefit I can open both valves to release the pressure
I found I couldn't get a completely airtight pot without the use of this stuff, joint compound, now it will hold pressure "forever".
To overcome the "blowout" potential problem and increase the capacity of my PP, I made up a 3 tier rack for the moulds (Gadget's as well as some I made) the top diffuses the air flow very nicely, the handle allows me to put it in the pot and take it out very easily.
I have attached a more complete description in a tutorial I did for Australia's Woodwork Forum.
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thewishman
Member
Thanks gentlemen!
TomW
Member
Fred,
This comment is not directed at you, but to the IAP community in general....
I think we should be very careful any time we recommend, suggest, imply or report that SAFETY devices be removed or disabled. Spinning carbide blades, electricity, pressure, and many other things can cause severe injury and DEATH.
We are all free to do what we want, and I admit I do some dumb stuff sometimes, but I try very carefully to never be in a position where my advise threatened others.
The relief valve on a pressure pot is there for a reason. If it causes problems, it should be replaced, not disabled.
Regards,
Tom
workinforwood
Member
BigShed
Member
Tom, you are obviously entitled to your opinion.
Let me just say that I would rather rely on setting my compressor to a maximum pressure below the rated max pressure of the pressure pot, than rely on the rather dinky "safety valve" that is supplied with these pressure pots.
Could I also say, I am not "recommending" anything, merely reporting what I did. People are free to do likewise or, as you did, decide that I am a fool.
TomW
Member
Fred,
I know, that as I grow older, more and more times I forget things, such as resetting the pressure setting after using the air compressor for pneumatic nailer, or impact wrench,turning off the stove, and stopping the water in the garden. I am safer with the relief valve in place. I also have fire extinguishers, fire alarms, and own a Saw Stop table saw.
I also know that there are hundreds of folks who find IPA and RELY on the information passed down from seasoned veterans of years of pen turning. I am one of them.
I dont think you are a fool. I think you are much smarter than I and have much better memory than I.
Regards,
Tom
I know, that as I grow older, more and more times I forget things, such as resetting the pressure setting after using the air compressor for pneumatic nailer, or impact wrench,turning off the stove, and stopping the water in the garden. I am safer with the relief valve in place. I also have fire extinguishers, fire alarms, and own a Saw Stop table saw.
I also know that there are hundreds of folks who find IPA and RELY on the information passed down from seasoned veterans of years of pen turning. I am one of them.
I dont think you are a fool. I think you are much smarter than I and have much better memory than I.
Regards,
Tom
BigShed
Member
Tom, I won't comment on the SawStop, I have seen more debate about that particular topic than I really need.
There is however a slight misunderstanding here, I think. The pressure relief valve on the pressure pot as supplied is there for a very good reason, if the pressure pot is used for what it was designed, ie applying constant pressure to a pot of paint inside so that it is fed up through a tube and to a paint gun.
Under those operating conditions I wouldn't dream of removing it.
However, we are not using the pressure pot for what it was designed.
I don't know about other people, but I don't keep the pressure pot connected to the compressor once it is up to pressure. As soon as I have it up to 60 psi, I shut the intake valve and remove the air supply. So there is nothing to forget, even if the compressor was set at 100psi. Once the air supply is removed there is als no way that the pressure can then inadvertently go up.
I certainly wouldn't want to leave my pressure pot unattended, say overnight, and rely on the pressure relief valve, I'd rather emove the air supply and know that there is now way of the pressure going.
It is also kinder on my compressor, if a leak developed somewhere it could potentially be running all night.
As reported in another thread, these pressure relief valves are not very reliable, this person reported that it triggered at 30 or 40 psi. I tested mine when it was still on there and I got up to 85 psi and it hadn't triggered! So it engenders a false sense of security. If I was going to rely on a pressure relief valve, I would go out and buy a quality one, not use the cheap HF type one.
And yes Tom, I do have fire extinquishers and fire alarms (required by law here in Australia), my car has seat belts (and I use them - also required by law here), I look left and right before I cross the street etc.
There is however a slight misunderstanding here, I think. The pressure relief valve on the pressure pot as supplied is there for a very good reason, if the pressure pot is used for what it was designed, ie applying constant pressure to a pot of paint inside so that it is fed up through a tube and to a paint gun.
Under those operating conditions I wouldn't dream of removing it.
However, we are not using the pressure pot for what it was designed.
I don't know about other people, but I don't keep the pressure pot connected to the compressor once it is up to pressure. As soon as I have it up to 60 psi, I shut the intake valve and remove the air supply. So there is nothing to forget, even if the compressor was set at 100psi. Once the air supply is removed there is als no way that the pressure can then inadvertently go up.
I certainly wouldn't want to leave my pressure pot unattended, say overnight, and rely on the pressure relief valve, I'd rather emove the air supply and know that there is now way of the pressure going.
It is also kinder on my compressor, if a leak developed somewhere it could potentially be running all night.
As reported in another thread, these pressure relief valves are not very reliable, this person reported that it triggered at 30 or 40 psi. I tested mine when it was still on there and I got up to 85 psi and it hadn't triggered! So it engenders a false sense of security. If I was going to rely on a pressure relief valve, I would go out and buy a quality one, not use the cheap HF type one.
And yes Tom, I do have fire extinquishers and fire alarms (required by law here in Australia), my car has seat belts (and I use them - also required by law here), I look left and right before I cross the street etc.
twoofakind
Member
I built mine on Curtis's design. I eliminated the tube on the inside, by unscrewing it, and replaced it with a 90 degree elbow. I ordered a dual guage and a new 70 psi safety valve from McMaster-Carr and attatched that to one of the inlets with a brass tee. I hooked up a ball valve and a male air nipple on the other inlet. The whole setup cost under $80 with the pot, the pot was on sale and I have under $30 in all the brass and guage.
i think my set up is similar, but not exactly the same as everyone elses.
first, i took the tube out of the bottom, and put a plug in the hole. I wanted to leave all the hardware on the top that was for the tube for possible future applications.
At first, i left my P.R.V. on. But when i pressured up, it leaked. so i tightened, and it leaked, so i tightened, and it broke. SO... I took it off, and discarded it. I put the guage on the top of the pressure valve thingy, and a pneumatic adaptor on each side. I then took an old die grinder that has no guts and hooked it up to the other side of the tree (sort of a manual P.R.V.). Now i just plug my little pancake compressor into the pot, and it starts pressuring up. My compressor is so small, it cannot fill the pot, so i hook it up, and the compressor runs, filling both the pot and the tank at the same time.
At 40 PSI, i kill the comp. and remove it. For me, these are all steps in a very scary, and dangerous chemical mixing situation, and i take great care in going through all the steps every time. Muscle memory, and the brain is indeed a muscle!
first, i took the tube out of the bottom, and put a plug in the hole. I wanted to leave all the hardware on the top that was for the tube for possible future applications.
At first, i left my P.R.V. on. But when i pressured up, it leaked. so i tightened, and it leaked, so i tightened, and it broke. SO... I took it off, and discarded it. I put the guage on the top of the pressure valve thingy, and a pneumatic adaptor on each side. I then took an old die grinder that has no guts and hooked it up to the other side of the tree (sort of a manual P.R.V.). Now i just plug my little pancake compressor into the pot, and it starts pressuring up. My compressor is so small, it cannot fill the pot, so i hook it up, and the compressor runs, filling both the pot and the tank at the same time.
At 40 PSI, i kill the comp. and remove it. For me, these are all steps in a very scary, and dangerous chemical mixing situation, and i take great care in going through all the steps every time. Muscle memory, and the brain is indeed a muscle!
Blind_Squirrel
Member
Various pictures of my setup: http://blindsquirrel.us/Scott/PressurePot/
twoofakind
Member
Those pictures are very close to what I did, except I only used a 70 psi gauge since my relief valve is set at 70 as well.
RHunter
Local Chapter Leader
Show me your pot?
Since we are posting pix of our HF PP...
I got all the parts, less the pot, from SurplusCenter, and I spent more in shipping then the parts. Total, including shipping, about $20.
And no just because the gauge goes to 150psi, doesn't mean I take it anywhere close to that! To the rated max of 80psi for me...
No regulator (more chances for leaks), I just leave my compressor on 100psi, and shut the ball valve when I get to pressure- then disconnect the air line.
Since we are posting pix of our HF PP...
I got all the parts, less the pot, from SurplusCenter, and I spent more in shipping then the parts. Total, including shipping, about $20.
And no just because the gauge goes to 150psi, doesn't mean I take it anywhere close to that
! To the rated max of 80psi for me...No regulator (more chances for leaks), I just leave my compressor on 100psi, and shut the ball valve when I get to pressure- then disconnect the air line.
bruce119
Member
I too though away the H.F. pressure relief valve in the beginning. Then I started developing leaks so I figure I had a pressure regulator set at 50. I left it hook to the compressor all night. Worked fine the compressor would cycle about 2 or 3 times a night maintaining 50 lbs. Until one night the H.F regulator failed and the pot took the full 100+ lbs that comes out my compressor .
I went rite out to Northern and bought a pressure relief valve.
I don't need a ticking time BOMB:doctor: in my shop.
.
.I went rite out to Northern and bought a pressure relief valve.
I don't need a ticking time BOMB:doctor: in my shop.
.
BigShed
Member
Bruce, I wouldn't keep my compressor connected to the pressure pot, overnight or otherwise, whether you have a pressure relief valve on it or not.
If the pressure relief valve does its' job in the scenario you describe,there is a good chance that your compressor will run all night and burn out a motor.
Much safer to disconnect the compressor from the pot, after all you only need the pressure on the cast for 20-30 minutes anyway, until it sets.
Best bet would be to fix the leaks.
If the pressure relief valve does its' job in the scenario you describe,there is a good chance that your compressor will run all night and burn out a motor.
Much safer to disconnect the compressor from the pot, after all you only need the pressure on the cast for 20-30 minutes anyway, until it sets.
Best bet would be to fix the leaks.
bruce119
Member
I got all that fixed now. I redid the pluming and it's air tight.
The thing I think that causes our pot's (at least mine) pluming to leak is the consistent hooking and unhooking of the quick connect air line. What I did to eliminate this problem is to put a soft connection on. That is that is hard wire a piece of air tube then put your quick connect on the flexible tube. Then you will not stress your pluming every time you connect and disconnect.
.
The thing I think that causes our pot's (at least mine) pluming to leak is the consistent hooking and unhooking of the quick connect air line. What I did to eliminate this problem is to put a soft connection on. That is that is hard wire a piece of air tube then put your quick connect on the flexible tube. Then you will not stress your pluming every time you connect and disconnect.
.
bruce119
Member
If you are using Alumilite maybe but PR takes a whole lot longer. And if you push it (more catylist) it will be as brittle as glass. I only use 3 drops per once and depending on the volume can take up to 8 hrs or more to harden. If you release pressure to soon your little tiny air bubbles that you can't see (the reason for pressure) will grow and pop like blowing bubbles with chewing gum.
.
JerrySambrook
Member
Actually, if there is a temperature rise, the pressure will go up as well.
If casting at 70 degrees in the morning, and the temp goes up to 95 ( as can happen, then there can be a dangerous increase in pressure. Also, if for some reason, the pot is in direct sunlight, and espaecially through a window, then the increase will be even more.
That is the best reason to put a good relief valve on the pot
Jerry
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TomW
Member
And dont forget that this is an EXOTHERMIC (releases heat) reaction that can also increase the pressures.
Tom
BigShed
Member
Jerry, yes theoretically you are correct. Could you quantify for me the pressure increase from the 60psi I work at if the external temperature goes from 70 to 95F?
The total mass of PR vs the total volume of air in the average load of a pressure pot would make this a highly unlikely scenario I would have thought. Add to this the mass of metal to absorb any increase in temp of the resin and it is even more unlikely.
I think there are as many ways of using a pressure pot as there are people owning them, whatever you are comfortable with.
Safety is a concern to most people, that does not however mean, for instance, that to use a tablesaw safely one has to buy a SawStop tablesaw, likewise with pressure pots.
BigShed
Member
Yes Tom, I am a retired chemist, I do know the meaning of EXOTHERMIC.
Again, I ask, can you quantify this increase in pressure?
twoofakind
Member
I figured better safe than sorry, so I set up my pot to release pressure at 70psi since I will not need anything above 60psi. I am also planning on building a sort of safety cage around the pot. I am going to add a shelf off the side of one of my workbenches to sit the pot on and will go ahead and enclose it and put a top on it that the pot can slide into and make some sort of bar to go across the lid....just in case. I know it is overkill, but I only have a garage workshop and my classic charger shares the other half of the garage.
peregine
Member
Just for everyone's general information. The increase in pressure is proportional to the increase in temperature, assuming of course that the volume does not change. Keep in mind to that this is not measured by the external temperature but the temp. inside the pot.
dalemcginnis
Local Chapter Leader
I agree. I always cringe when I read that someone has removed a safety device saying it's not necessary. I've read of too many accidents because someone removed a "secondary" safety device because the primary was enough. Remember the pressure regulator on your compressor is NOT a safety device and how do you know it is accurate anyway? Do you test it EVERY time you use it? If not it could have gone bad since the last time. And even if you do test it who's to say it wont go out in the middle of pressurizing your pot. Those of you who have removed the safety devices are an accident waiting to happen. It's not if, it's when!
el_d
Member
Chris this was simplest for me. Just got a tire valve and white tape. I dont use the gauge just a tire gauge as I inflate the pot. Takes about 30 sec to 60psi and no need for an elbow on the inside either. Could have just plugged the other side but tried to get fancy and used some extra fittings(not necessary).
Attachments
thewishman
Member
Thanks for all of the input, ideas, suggestions and especially the pictures! I'm keeping an eye on the pressure pots at HF and waiting for my local store to put them on sale.
I bought (and paid for shipping) a pot from someone who used to be here last fall, but he had some health problems and hasn't been here since December. Hope he gets better soon.
I bought (and paid for shipping) a pot from someone who used to be here last fall, but he had some health problems and hasn't been here since December. Hope he gets better soon.
mbuckley52
Member
Thinking about building a pot.
I am thinking about building a pressure pot for casting, I am looking for a 5 cfm vacuum pump for my suction system on the lathe, will this pump also work for this?
Any help in the north Texas area, (Ft Worth)
thanks
mbuckley
I am thinking about building a pressure pot for casting, I am looking for a 5 cfm vacuum pump for my suction system on the lathe, will this pump also work for this?
Any help in the north Texas area, (Ft Worth)
thanks
mbuckley
mbuckley52
Member
more ideas
would this pot work?
2-1/2 Gallon Pressure Paint Tank from hr?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=66839
thanks
mbuckley52
would this pot work?
2-1/2 Gallon Pressure Paint Tank from hr?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=66839
thanks
mbuckley52
PTownSubbie
Member
This is the pot that most people use. I don't know anything about the vacuum though.
NewLondon88
Local Chapter Leader
The vacuum pump works fine with this pot. You'll need a different gauge ,though.
I think I got a combination pressure/vac gauge for about $12.
I think I got a combination pressure/vac gauge for about $12.
mbuckley52
Member
Jack
when I get ready can i pick your brain?
I won a 6cfm vacuum pump on ebay and I will use it for a vacuum system on the lathe.
it may be a few months before I get ready.
saving my money to get an iphone.
thanks
mbuckley52
when I get ready can i pick your brain?
I won a 6cfm vacuum pump on ebay and I will use it for a vacuum system on the lathe.
it may be a few months before I get ready.
saving my money to get an iphone.
thanks
mbuckley52
td
Banned
Mark,
Our shop is in Arlington. We have 4 of these pots. We deep dye and stabilize pen blanks and cast blanks as well. You're welcome to send me a PM and come on over one day. Have a great one!
Terry
Texas Wood House
Our shop is in Arlington. We have 4 of these pots. We deep dye and stabilize pen blanks and cast blanks as well. You're welcome to send me a PM and come on over one day. Have a great one!
Terry
Texas Wood House
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