2.5 Gallon Paint Pot Conversion

I figured I might as well post a bit about this here. I am hoping those with more experience will give feedback and that those who want to do their own conversion will have additional information on how to do this.

At first I was rather overwhelmed about the idea of making my own pressure pot. I am fearful that I might do it wrong and either cause serious injury to myself or property. I have never did this conversion before and all the information I have is from researching various websites on how others have done this conversion. So my warning is, do the conversion at your own risk. Use the converted pressure pot at your own risk.

First off, the pressure pot I am using is a 2.5 Gallon Paint Pot that I bought from Harbor Freights. After sale price, coupon discount, and tax it came out just under $70.

Below is a picture of the parts included in the box. **Note, the lid is laying flat because I have already removed the paint tube attached to the lid before I thought to take a picture.


2.5 Gallon Paint Pot by Mothi03, on Flickr

Below is a picture of the top of the lid close-up.


Paint Pot Lid by Mothi03, on Flickr

All I have done so far is remove the paint tube attached to the lid. It came off rather easily with a wrench. I will post more as I progress. Eventually I will have a more detailed post on my blog about the conversion. My next step is to get the various parts I need. I have also decided to purchase a Ryobi 3-Gallon Air Compressor from Home Depot. Unfortunately I have to order it online since it is not sold in stores...sigh.

 

Converting a paint pot into a casting pressure pot is posted many times on various forums when it comes to casting resin.

There seems to be 2 basic ways to do the conversion, depending on whether you use the regulator or not.

With regulator...

View attachment 48

Without a regulator...

View attachment 49

Trying to decide which way I want to go. I also deciding whether I want to have the pressure pot vertical or horizontal.

The diagrams above come from Fleafa's Photobucket Gallery. They show very well the differences. Although I have seen some pressure pots which look a lot more complicated, but I think some of those are dual pressure pot and vacuum tanks.

 

Here is a teaser of what I have so far.


Pressure Pot Conversion Teaser by Mothi03, on Flickr

It is loose fitted only. I want to make sure this is what I want before I do a tight fit. So far I have spent $25 on the parts you see. You could definitely do it for cheaper but... I will explain more about parts, cost, and reasons later.

But I will say that once you know what size you need and the basics to what parts you need, it is easy to figure out. It isn't as hard as I thought it would be.

EDIT: I have been playing around with the parts I have and made some changes. I am missing a few parts I will pick up tomorrow and will post what I got. Basically, I had to decide whether I wanted a regulator on the pressure pot or not. My decision was to NOT use a regulator on the pot itself. The air compressor does have a regulator. So that lightens and simplifies the setup. More tomorrow... I hope. Then I get to do a test run with the compressor.

My air compressor did arrive yesterday and my Smooth-On order should be arriving today. I ordered Smooth-Cast 305 and a platinum silicone rubber to use.

 

I have a minor set back.

I decided to test out my newly converted pressure pot with my newly purchased air compressor and there were a few leaks. I fixed one with some teflon tape and the other leak was at the safety valve. Exact on safety valve is unknown. The problem is when I tested the pressure in the tank up to 40 psi, the safety valve blew. So I guess the safety that comes with the pot is only rated to 40 psi? What pressure do I need to get the tank to?

When I was shopping for parts I didn't see any safety valves within the rating I needed. The only ones I saw were rated over 100psi. I can probably order a 60 psi one online but it will takes days for it to arrive. I am running out of time to do my casting before Christmas arrives.

I will post pictures soon, but I might do another change depending on how I feel about the current set-up. So far I am rather pleased.

 

Here is a picture of my pressure pot as of today.


Casting Pressure Pot by Mothi03, on Flickr


Pressure Pot Conversion by Mothi03, on Flickr

I am going to see if I can add a small regulator. The only problem is... some parts labeled as regulators are not pressure regulators but more like a valve you can adjust the air flow. So in a sense are air flow regulators and not pressure regulators. The total cost for my conversion so far is under $15. I bought most of my parts from Harbor Freights. I noticed that Home Depot was almost double the cost of Harbor Freights for comparable parts.

 

I did purchase a smaller less bulky pressure regulator from HF and just did a test run with it on. I still need to do some adjusting though. The pot from HF is working pressure rated for it is 30-60 psi. The maximum pressure is 80 psi. I did order a 60 psi safety valve from ebay so I can be sure never to go that high. I figure I can use 50-55 psi of pressure for making silicone molds and casting. That would be within the working range and below the ordered safety valve rating.


Latest update on Pressure Pot Conversion by Mothi03, on Flickr

The air compressor I have has a regulator on it.

I am also losing air somewhere. The pressure dropped 10 psi in 10 minutes. I can't hear any more hiss nor feel the leak. So I am guessing I need to mix up some soapy water to see where it bubbles up.

 

Okay, the air leaks are being narrowed down. Using soapy water definitely helps. I made sure to wrap the teflon tape multiple times around the thread, which helps many of the leaks. Now I just have one leak left in an easy to access spot then all should be golden.

I did order a safety relief valve from ebay and am awaiting its arrival.

I also made a removable inline desiccant dryer/filter section to help remove air moisture from the incoming air. I may replace this later with something else, but in the meantime this is my current set-up.


Pressure Pot Conversion by Mothi03, on Flickr


Pressure Pot Conversion by Mothi03, on Flickr


Pressure Pot with Inline Dryer by Mothi03, on Flickr

NOTE: I don't have a safety relief valve in the above pictures. While awaiting its arrival I put something else there to plug up the air. This is only temporary so I can test pressure. I have been very careful about the psi in the tank watching both gauges.

Total cost of basic parts is about $20. The new safety relief valve is about $8. And the inline dryer section is about $12. So total cost was about $40.

I am rather pleased with my set-up and feel much more comfortable using it since I have been doing a lot of tests trying to locate all leaks. I think finding the leaks was a pain in the rear...

More details is posted on my blog.