# Setting up a pressure pot for use



## hilltopper46 (Aug 30, 2006)

I had posted this to the classifieds section (because I had an extra pot for sale and was asked how I set it up).  I think it belongs here.

Shopping list ~$8.00 at my local Ace Hardware store.

1 - 1/4-inch pipe to 1/8-inch brass pipe reducer bushing
1 - 3/8-inch pipe to 1/4-inch brass pipe reducer bushing
1 - schroeder valve (used on pressure tanks for well systems)

Procedure:
1. Remove the down-pipe that extends from the lid down into the can so you don't need to worry about arranging the mold(s) around it. I had to take mine apart (both fittings take a 13/16 inch wrench or a big Crescent wrench) and put the pipe in my vice to turn the fitting off the end. Reassemble the through-fitting back into the lid - you may want to add some sealer - I did not.  Make sure the gasket positioned properly in the fitting.

2. Remove the pressure gauge from the regulator assembly.

3. Remove the adapter elbow from the through-fitting for the paint pipe.

4. Use the 1/4 to 1/8 pipe reducer bushing to fit the Shroeder valve to the air-hose fitting on the safety/release valve. This bushing MUST have a machined taper to fit the swivel type of fitting on the pot. Use Teflon tape between the bushing and the Shroeder valve but NOT between the bushing and the swivel-nut.

5. Use the 3/8 to 1/4 pipe bushing to fit the pressure gauge on the through-fitting for the down-pipe. Use teflon tape on both threads.

My pot is holding over 30 lbs of pressure overnight setup this way.

A couple comments:

A. The gauge that came with the pot reads about 5 PSI too low - this is somewhat dangerous as excessive pressures could possibly be built in the pot because the gauge doesn't read as high as it should. Use a known accurate tire gauge to double check the pressure reading on the pot until you are comfortable with the accuracy of the gauge mounted on the pot.

B. The safety/release valve is adjustable. Don't adjust it without the use of an accurate pressure gauge. Mine starts to blow off now at about 50 PSI - this is good. It seems to be leaking down to about 30 PSI overnight, most of which occurs in the first 1/2-hour or so. From reading other posts, this is sufficient to remove the bubbles from the casting. I've made two casts and bubbles aren't evident in the cast when I remove it.

C. The pot has a rounded bottom which makes it very easy to have the molds in the pot in an unlevel situation. I haven't figured out how to overcome this yet (although I think I'm close). At the very least a small cheap level should be used to check the levelness of the mold before the lid is put on the pot.


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## cozee (Aug 30, 2006)

As for leveling the bottom of the pot, why not simply pour in some resin and allow it to harden?!!!! It for the most part should be self leveling. Just make sure the pot is on a level surface. If need be, one can prefill the pot with water to get an idea on how much resin will be needed. And for those who need to ask for the valve, they are also known as a"_Schrader_" valve.


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## chigdon (Aug 30, 2006)

I appreciate the tutorial.  I just got the pressure pot (still in box) and will go get these pieces today!


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## JimGo (Aug 30, 2006)

Thanks Tony!!!!


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## Dario (Aug 30, 2006)

Printed...will be hitting the store tonight (hopefully).

I tried to remove the tube 2 weeks ago and can't even make it budge!  I used a vise grip on the tube and an adjustable wrench.  I'll try again tonight (maybe freeze it first []) in case the aluminum expanded more than the steel fittings due to heat in my garage.


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## JimGo (Aug 30, 2006)

Glad to know I'm not the only wimp, Dario!


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## Dario (Aug 30, 2006)

LOL.  

Worst  case scenario...I will end up cutting the aluminum tube.


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## its_virgil (Aug 30, 2006)

A hack saw worked really well on mine[]

Cut a plywood disk to just fit inside the tank and let is fall to the bottom for a flat bottome surface.  As mentioned, leveling the tank make the castings nice and even all the way across the mold.

Do a good turn daily!
Don


> _Originally posted by Dario_
> <br />Printed...will be hitting the store tonight (hopefully).
> 
> I tried to remove the tube 2 weeks ago and can't even make it budge!  I used a vise grip on the tube and an adjustable wrench.  I'll try again tonight (maybe freeze it first []) in case the aluminum expanded more than the steel fittings due to heat in my garage.


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## alamocdc (Aug 30, 2006)

Hey, I own a hack saw... and I'm cheap![]


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## Dario (Aug 30, 2006)

I think my Dremel with the diamond cut off discs will cut more flush to the fitting than a hacksaw [] LOL

BUT...the vise grip and wrenches will have another shot first...TONIGHT! []


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## hilltopper46 (Aug 30, 2006)

I cut a flat plywood disk to put in the bottom of the pot, but I cut it from plywood that was too thin (~1/4-inch).  It needs to be thick enough that the edges act as a guide (for lack of a better word) to keep the disk from tilting. In fact, I may add some scrap wood around the edge to increase the effect.  I think I'll see if I can find a 3/4-inch scrap piece large enough for this tonight.

Also - call me paranoid - but I will drill some holes through this disk to allow for pessure equalization as the pot pressurizes and de-pressurizes.

I think the down-tube is galvanized steel - not aluminum.

The reason I did things the way I did is that I wanted to be able to put the pot back to use as a paint pot if I ever wanted to. I never really considered cutting it off - it would have been quicker.


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## Charles (Aug 30, 2006)

Great tips guys, I pick up my potthis afternoon. My harbor freight has three left. I'll be doing like dario tonight.


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## melogic (Aug 30, 2006)

Tony (and everyone else), Thanks for sharing this information. It's a big help. Now for a few more questions: What resins, catalyst and dyes are you guys using? Is there somewhere I can get small quanities to try this procedure out before I invest a lot of money in resins? How long do you let the resins set under pressure?


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## Charles (Aug 30, 2006)

melogic, there is a very good tutorial here by Jay Pickens at (www.penturners.org/content/PR.Instructions.pdf). Also another great tutorial is Anthony's of www.penworks.us but I don't know the link. I know it's here on the IAP somewhere but I can't seem to find it to send the link. Maybe someone else knows where it is.


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## Dario (Aug 30, 2006)

They are both on the library.


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## melogic (Aug 30, 2006)

Thanks Dario and Charles. I just found them and was headed back here to let anyone else that wanted to know, know.


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## its_virgil (Aug 30, 2006)

Mark,
I am purchasing resin from http://www.mrfiberglass.com  The cost is (for me..shipping varies) $35 and change for a gallon with catalytst. Michaels and Hobby Lobby have it for about $22 per quart but often have 50% off couopons for a single item purchase which makes it around $11 or so for a quart. mrfiberglass.com also has a few dyes byt Douglas and Sturgess (http://www.artstuf.com) has a much better selection of colors, but their resin is $41.35 per gallon + shipping. Have fun and show us some pics. Do a good turn daily!
Don


> _Originally posted by melogic_
> <br />Tony (and everyone else), Thanks for sharing this information. It's a big help. Now for a few more questions: What resins, catalyst and dyes are you guys using? Is there somewhere I can get small quanities to try this procedure out before I invest a lot of money in resins? How long do you let the resins set under pressure?


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## MesquiteMan (Aug 30, 2006)

Here is a picture of a rack I built for my pressure pot.  The square part on the bottom is actualy just something to set it on while out of the pot.  The center dowel goes all the way through and stick out the bottom about 2 inches.  This is what keeps it up off the rounded bottom.

The 1/4" ply at the top is an air deflector to keep the air that is rushing in while filling from blowing the resin out of the mold!


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## Charles (Sep 1, 2006)

I like the deflector lazy susan curtis, good idea.
Tony check your email please, Thanks


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## PenTurnerJohn (Sep 2, 2006)

> I am purchasing resin from http://www.mrfiberglass.com The cost is (for me..shipping varies) $35 and change for a gallon with catalytst. Michaels and Hobby Lobby have it for about $22 per quart but often have 50% off couopons for a single item purchase which makes it around $11 or so for a quart. mrfiberglass.com also has a few dyes byt Douglas and Sturgess (http://www.artstuf.com) has a much better selection of colors, but their resin is $41.35 per gallon + shipping. Have fun and show us some pics. Do a good turn daily!
> Don



I remember reading an article by Jay Pickens mentioning buying casting resin from Douglas and Sturgess at a cheaper price but I'm sure inflation hits everyone.  Does anyone else have a good source of casting polyester resin?

John


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## buzzb (Oct 4, 2006)

Just got back from a trip to Angboy's new shop in West Va. to work on her pressure pot and powder coating system.  Many thanks to Hilltopper46 for his excellent writeup and pictures on the pot.  We followed his approach with the use of slightly different adapters.  we used the soap bubble approach to find and correct a couple of leaks.  We still had  a drop of over 20 Psi overnight.  It turned out to be rust in a couple of spots on the rim of the pot.  A LIGHT sanding with 1500 grit paper smoothed this up and got the pressure drop to about 2 Psi overnight.  Something to check if you are having excessive pressure drops.


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