Higher pressure than a typical pressure pot can handle....

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redfishsc

redfishsc

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I've been thinking. I have a 20lb CO2 canister that I don't use too often.

It hangs around 900 PSI and is full of liquid CO2.


Just imagining the possibilities if I could find a way to harness, say, 200-400 PSI safely.

I know that paint pressure pots WILL NOT WORK so don't think I'd ever try it, or I'll be swimming my last lap around the ocean:eek:.


But what *could* handle that kind of pressure?


And some of you are asking "why"?.

Well, why NOT?:D
 
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You know, there are some things that I play around with that are plum dangerous to others and I don't think a thing about it. But for some reason, real high pressure tanks and fittings like that scare me.

Growing up on a farm in the '50s and '60s, One of my jobs was stump removal - with dynamite! That was fun! But a high pressure tank like that for me . . . I don't know about that.

Let us know how it goes - if you do try it.
 
I'm curious, but I don't completely understand what you are asking. The working pressure of my scuba tanks is 3500 psi. They are hydro tested to over 5000 psi. So, a few hundred psi is nothing in that context.

What are you looking to do? It could be fun.
 
Interesting idea ...
I asked about this (using a CO2 cartridge as a source of 'air' to pressurize a PaintPot to a normal level, say 20-40psi) but was told that the CO2 would be too cold when it left the tank .. my dad uses a CO2 tank to drive his brad nailer, because using a compressor around apartments is too noisy and requires electricity and such .. and for this it works great ..

It would be interesting if there was some way to get the "resin in a mold" inside some container, and then pressurize it up to 200 psi .. say for a "Worthless Wood" experiment .. I would be curious if it penetrated any deeper than say the normal range of 40psi ..
 
Red, hold off on putting a lot of pressure in a pot. I have brought one up to 200lbs and it held, but I wouldn't advise doing it. One of the weak links did let go and someone did get hurt so we stopped playing with it. The scuba tanks will hold plenty of pressure, but the opening is a little small for casting....LOL

By the way, that pot is not being used for anything anymore. I don't trust it.
 
You could construct a pressurized cylinder out of schedule 80 PVC pipe.

Standard Sch 80 operating pressures (OP) are:

4" 194 psi
3" 225 psi
2 1/2" 255 psi
2" 243 psi
1 1/2" 282 psi
1 1/4" 312 psi
1" 378 psi

Keep in mind these pressures are for operating temps (OT) in the low 70's. Max OT for PVC is 140 F at which the OP are 20% of those in the 70's. Fitting choices will vary the OP also. I have a 3" casting cylinder that I've regularly run and held at 175 psi with no problems what so ever. My old compressor will not go any higher!!
 
Thanks guys.

Just for the record (and I thought I put this forth in the opening post) I AM NOT ABOUT to pressurize a paint pot that high. I use a paint pot every week, and I know their limits.



I only ask because of what Jeff mentioned--- wood experiments.


As far as the temp of CO2---- the temp is caused by the fact that the CO2 in a canister is liquid. When it becomes a gas, it takes on a lot of heat (well, compared to -109F of liquid stuff). I think you should be able to keep a reasonable temperature with CO2 so long as you don't pressurize it to the point of making it liquid again (which would be insidiously stupid b/c it would freeze the resin and perhaps blow up whatever you are using as a pot---- and you---- and your little dog too!).


Thanks Greg for the recommendations--
 
Look at the recommendations of the manufacturers of PVC pipe and they will all say you should "NOT" use them for high pressure air.

Making a high pressure vessel out of PVC is an accident waiting to happen.
 
IIRC, the stamdard home pressure cooker is designed to work at about 15 PSI. I'm sure the safety plugs would start blowing out at not much above that pressure.
 
Randy_ said:
Look at the recommendations of the manufacturers of PVC pipe and they will all say you should "NOT" use them for high pressure air.

Making a high pressure vessel out of PVC is an accident waiting to happen.
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My bad. :D Simply double sleeve (passive outer) with a vent on the outside sleeve. Problem solved.
 
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brokenbit said:
Just dumb to run that high of pressure, It will KILL you
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So can choking on a grape. It's a matter of safety, technique, and equipment. I have a canister of CO2 that has nearly 1,000 PSI in it, like it's supposed to, and I'm still alive.

The matter is WHAT you are containing the pressure in, which is the reason for the post-- asking what is made to handle such things.
 
One thing to consider is that when you put the CO2 into your pressure vessel it will be making the environment inside the vessel colder and this will affect your cast cure time.
 
Just throwing out a suggestion. Maybe a slower curing time would be advantageous. It might allow more times for the bubbles to work out. I could be wrong.
As for what would hold more pressure, I'll have to dig something dad and I got out of storage. It's a computer controlled unit that's got both a vacuum and a pressure in it. I can regulate pressure and vacuum with digital dials and such. It has a pot with an ID or 16" by about 24"-30" ( can't remember exactly). And the pressure vessel is 3/4 inch thick steel with almost a 2" lip. The lid is held in place by around 20 3/4" bolts. It's rated to take 2000 PSI if I remember right.
Dad and I got it out of a lab of a paper mill. They also had some 10 foot in diameter 3" walled pressure vessels. They are spherical, and I can't remember, but think they were rated for 1000 psi. I know where to get the ones from that plant. No one has cut them apart.
Too bad you weren't closer, although I'd need to hook up 3 phase power, meaning I get to run the generator overnight. Would be cool for stabilizing wood. I wonder if at that pressure if you could stabilize snakewood.
Should start a poll to see how many people think that you could stablize a 7/8 inch snakewood penblank at that pressure 2000 PSI. Or should that be taking bets????:D:D:D
 
Do you have the means to bring the pressure that high? My brother was using an industrial compressor that has to be towed around when he attempted to blow up the pressure pot. The thing has an 8 cylinder motor on it and the operating costs would outwiegh the benefits. It could be fun though, I say go for it.
 
I"m not sure about the compressor. I haven't taken it apart to have a look. Apart means taking all the sheet metal off the sides. The guy that we got it from said he had it up to 2500 psi. The electrical motor on the machine is a 3/4 horse which I think is small. Although it depends how it's geared too.
I think the add for the machine should have read "Diesel generator sold separately." :p:p:p:D:D:D
 
Interesting question that begs the further question....Why?
If apx. 20 lbs works, as it does for most here, pushing the limits of safety seems unnecessary. I can see experimenting with a bit more pressure, like up to 30 lbs. But, in the hundreds???? It is hard to imagine that the return will justify the effort and risk.
As to the PVC, putting plastic solvents into plastic vessels seems a formula for disaster. I understand that Nalgene might resist acetone but not sure about PVC. Can anyone here speak expertly to that?
 
everything I've ever seen that's designed to hold that type pressure is a solid tank with a narrow opening (scuba tanks, air compressor tanks, helium tanks, etc). The only think that comes to mind that might be able to is a boiler of some type, but I don't know it they'll have an opening large enough to be of any benefit.
 
Rifleman1776 said:
Interesting question that begs the further question....Why?
If apx. 20 lbs works, as it does for most here, pushing the limits of safety seems unnecessary. I can see experimenting with a bit more pressure, like up to 30 lbs. But, in the hundreds???? It is hard to imagine that the return will justify the effort and risk.
As to the PVC, putting plastic solvents into plastic vessels seems a formula for disaster. I understand that Nalgene might resist acetone but not sure about PVC. Can anyone here speak expertly to that?
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I cast at 120# and it is more than sufficient for anything. I have to agree with Frank, pushing for the sake of pushing is reckless, leave that to people that are trained for it. My brother did some testing with pots a while back and even with all the safety steps they undertook 2 people were injured anyways. All involved(Military, Fire Dept., Police Dept.) were trained with explosives and it just took one weak link to cause injuries. Noone can tell you what to do, so whatever you choose to do, be careful and be safe.
 
jwalt191 said:
You might look at some of this link. Interesting, at the least.

http://www.highpressure.com/reactor_guide.asp

I have thought about using a pressure cooker, I don't know what the operating pressure would be though.

Let me know what you find out.
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On an earlier post, I asked about using a pressure cooker and got several emphatic "Don't do it", but if I remember my mother's canning processes, she use to pressurize her canner to about 20 psi on the gauge it did have a red line maximum, but don't remember the red line ... the one she had was a cast metal of some kind with wing bolts that flipped up every 4 to 6 inches around the rim... probably 6 or 9 bolts.. and there was a safety relief valve on the top. Newer canners are steel, some have separate bands that hold the lid on, much like the tension bands on barrel drums. I don't have a compressor so I can't experiment... and isn't the air coming out of a compressor hose cooler or cold...
 
ozmandus said:
On...and isn't the air coming out of a compressor hose cooler or cold...
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Sort of depends. Chuck. As air or any other gas for that matter is compressed, it heats up. Place your hand on the head of an air compressor or the line between the head and the tank and you will prove that point for yourself. If the compressed air is vented to the open atmosphere (your example above), it will rapidly expand, give up its heat and feel cool/cold.
 
I wouldn't waste my time, but otherwise here is my theory.
You pump enough pressure into the cells of a piece of wood, the wood will explode. There is air inside those pours and they lead to a dead end, so you keep pushing and pushing, it has to go somewhere, so it blows out the cell walls.
You want to stabilize snakewood, maybe you need 200 lbs of pressure, but vaccuum pressure is what you will need, not air pressure. You have to force the air out of the cells before anything can get in, and no doubt the cell walls of snakewood are very small.

Then there's just regular casting. Don't you figure that eventually whatever your mold is just can't handle the pressure anymore and implodes in the tank? Surely there has to be a point when there is just too much pressure period.
 
I don't disagree with you, Jeff. But, the other side is that you will never know until you try. Even if it's only one piece to try. Who knows, it might be the accidental discovery of something completely new, just like the sticky note.
 
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