Pressure Pots

Woody · Post by **Woody** » Mon Aug 04, 2008 9:51 pm

What size do most people use? I'm going to start casting quite a bit next year and would like to get a nice pot but I'm wondering if 2.5 gal is big enough. Source suggestions?

Joseph Osborn · Post by **Joseph Osborn** » Tue Aug 05, 2008 12:36 am

I suppose the obvious answer is to use a pot big enough to hold the largest mold you need to pressurize. For me so far, the 2.5gal pots have been plenty big, but my stuff tends to be small. Look here for some ideas about sizes and costs:
http://www.mcmaster.com/#catalog/114/2084

Google is your friend, too. Sometimes the variations in dimensions between different manufacturers' 2.5gal pots is enough to make a difference for your application.

Used pots come up on EBay regularly, so sometimes you can get lucky there.

While we're talking about pressure pots, do you think I could clean the resin drips out of the inside of my pots by putting a firecracker in there and slamming the lid down?

Woody · Post by **Woody** » Tue Aug 05, 2008 9:49 pm

Thanks for the reply. I want to mount two pots to a casting bench so I want to be sure I chose the right size. I'm thinking 5 or 10 gal might be best.

Antenociti · Post by **Antenociti** » Wed Aug 13, 2008 4:48 pm

five 2.5 gallon pots and two 10 gallon pots

though to be fair we rarely use the big pots for anything actually that big, the 2.5 gallon pots do most of the real work.

big pots were picked up second hand on ebay for a pittance from a factory closure/repossession company who clear stuff on ebay. took three months waiting to get them but very well worth it.

Woody · Post by **Woody** » Wed Aug 13, 2008 8:33 pm

I think I'll start with a pair of 2.5 gal pots. On a similar note my vacuum pump arrived yesterday.

Any brand preferences on pressure pots?

Antenociti · Post by **Antenociti** » Thu Aug 14, 2008 2:06 pm

i imported mine from Harbour Freight in the USA - they had a special offer on so there were only about $30USD or something equally mad (£275.00 ~ $450USD I was quoted in the UK for the same size pot).

Even after shipping and VAT and import duties they were massively cheaper than anything in the UK.

There is an article on the site here somewhere that also discusses them and advises making anew seal for the lid - I totally agree. The one that comes with them is a very hard rubber and you cant always get a perfect seal so you lose pressure overnight. I replaced mine with some soft silicone and they stay sealed perfectly. I think mine are over 2 years now without any problems whatsoever, haven't even needed to replace the (replaced) seals and we cast atleast 5 days a week and 4-7 times a day in them.

The ..erm.. "screws" (the thingies you tighten them up with) did get very stiff after a while - i removed them and found a lot of very fine steel shaved off in the thread, dusted that off and added some WD40 oil and they are easy and smooth to tighten now.

Shizman · Post by **Shizman** » Sun Apr 04, 2010 7:53 am

What is the difference between getting a pot from Harbor Freight and one that's specially made for casting, such as ones from Smooth-On? The prices are vastly different.

Harbor Freight:
http://www.harborfreight.com/cpi/ctaf/d ... mber=66074

Smooth-On:
http://www.sculpturesupply.com/detail.php?id=252415

I'm considering importing the Harbor Freight one since it'll be cheaper, even after shipping and any duty that's added.

Stu Pidasso · Post by **Stu Pidasso** » Sun Apr 04, 2010 8:31 am

Joseph Osborn wrote:While we're talking about pressure pots, do you think I could clean the resin drips out of the inside of my pots by putting a firecracker in there and slamming the lid down?

Sure! I could use the extra work while you regenerate arms.

Shizman wrote:What is the difference between getting a pot from Harbor Freight and one that's specially made for casting, such as ones from Smooth-On? The prices are vastly different.

Other than style (like bigger wing nuts) nothing. I've been using the Harbor Freight ones almost every night for 2+ years now, and they are still going strong.

Shizman · Post by **Shizman** » Sun Apr 04, 2010 8:48 am

Other than style (like bigger wing nuts) nothing. I've been using the Harbor Freight ones almost every night for 2+ years now, and they are still going strong.

Good to know. I'm in the market for one and want to make sure I get something that's going to work well. So 40 psi should do the trick?

Anyone know of a place in Canada that sells these pressure pots? I'd rather not import it and deal with the duty if possible.

Stu Pidasso · Post by **Stu Pidasso** » Sun Apr 04, 2010 8:59 am

Shizman wrote: So 40 psi should do the trick?

I usually run around 45psi.

Johnnycrash · Post by **Johnnycrash** » Sun Apr 04, 2010 9:08 am

Shizman wrote:Anyone know of a place in Canada that sells these pressure pots? I'd rather not import it and deal with the duty if possible.

Importing (with duty and taxes) is still cheaper than getting one in Canada. I just picked up a 10 gallon pot for $100.00 from the US. The exact same pot here in Canada can't be had for less then $600.00. So, even with 100% duty/taxes, AND $100.00 shipping... It's a bargain.

But, if you can find a border guy to bring it across for you, the shipping (for mine at least), will be about $50.00, and no taxes/duty (at best), or only the tax of 13%. So...

Shizman · Post by **Shizman** » Sun Apr 04, 2010 9:09 am

Johnny, which pot did you choose and where did you get it?

Johnnycrash · Post by **Johnnycrash** » Sun Apr 04, 2010 9:15 am

Sorry. It was a 5 gallon, not 10. Too many numbers in my head. GET OUT!! GET OUT!!!

What?? Yeah, I'm feeling better now, thank you.

This is the pot I got - 5 Gallon Pressure Paint Tank

Shizman · Post by **Shizman** » Sun Apr 04, 2010 9:29 am

Johnnycrash wrote:Sorry. It was a 5 gallon, not 10. Too many numbers in my head. GET OUT!! GET OUT!!!

What?? Yeah, I'm feeling better now, thank you.

This is the pot I got - 5 Gallon Pressure Paint Tank

Cool, that's the exact one I'm about to order. I just wanted to know that others have had success using it.

Thanks everyone!

Shizman · Post by **Shizman** » Tue Apr 06, 2010 9:58 am

Any preference for a good compressor to power the pot? I want something reliable. What do you guys use?

Shizman · Post by **Shizman** » Fri Apr 09, 2010 7:50 am

Ok hopefully this will get a reply.

Anyone know where I can get air line components such as adaptors, inline stop valves, etc, preferably in Canada?

Johnnycrash · Post by **Johnnycrash** » Fri Apr 09, 2010 8:34 am

Get the biggest, most powerful one you can afford. Really. Since you are a Canuckian, Canadian Tire has sales all the time. Look for something in the 3.5 SCFM @ 40psi (casting pressure) or greater. They should have all the other bits you will need as well. AND, if you don't have one near you, they do mail order. This is the compressor that I am running now.

Shizman · Post by **Shizman** » Fri Apr 09, 2010 8:36 am

Ya, i was looking at something similar at Home Depot.

What about all the connectors to change this from a painting pressure pot into a simple pot? Where did you get your connectors to do this (e.g. stop valves, adaptors, etc)?

Johnnycrash · Post by **Johnnycrash** » Fri Apr 09, 2010 8:45 am

I got all my bits at an auto/hardware supply store. Only because they were closer, and I needed to make several trips as I figured it all out.

But CT should have all the bits.