Any tutorials for converting a Harbour Freight Paint pot into pressure casting pot?

[Anakin Starkiller]

Hey guys,

I was wondering if there are any tutorials available that will give me instructions on converting a Harbour Freight Paint pot into a pressure post suitable for pressure casting? I know that I have to replace the hardware, and I could probably figure alot of the process of convfersion on my own, but I was wondering if anyone has done a write up about the whole nine yards.

Thanks

Dan Stokes
DDStokes@aol.com

 

[blufive]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

I have one of these pots and if I recall correctly, there's very little work needed to convert it. I think all you have to do is add a fitting so your air line can attach but I can't remember if that's all...

 

[wuher da brewer]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Give me a minute and I'll put up a picture of mine. I added a couple ball valves on it, a quick connect, and a gauge.

One ball valve is between the quick connect and the gauge so I can close it and maintain pressure after it comes upto pressure on the gauge. The other ball valve is on the other hole in the lid.

Obviously there is a bit of redundancy on mine since I built it with parts I already had at home. There are literally 4 air out valves on mine, when 1 might do it. You could probably just seal off one of the top two holes, though I put a ball valve on it. I like having at least two air out points.

 

[Tiki]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

For what it is worth we used to use a pressure cooking pot in LA for casting things in dental acrylic. Worked really well for small molds - best part is that the lid is easy to get on and off really fast. I dunno how big the molds you have are - but maybe that is an option?

Tiki

 

[Mickeymoe]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Give me a minute and I'll put up a picture of mine. I added a couple ball valves on it, a quick connect, and a gauge.

One ball valve is between the quick connect and the gauge so I can close it and maintain pressure after it comes upto pressure on the gauge. The other ball valve is on the other hole in the lid.

Obviously there is a bit of redundancy on mine since I built it with parts I already had at home. There are literally 4 air out valves on mine, when 1 might do it. You could probably just seal off one of the top two holes, though I put a ball valve on it. I like having at least two air out points.

What is the inside did.of the pot?

 

[Mickeymoe]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Does any one know the inside diameter of a 2 1/2 gal Harbour Freight Paint pot?

 

[aliendred]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

im very interested in this.. i could def use something like this.. LETS GO TUTORIAL

 

[Rebelscum]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Does any one know the inside diameter of a 2 1/2 gal Harbour Freight Paint pot?

it's 9-7/16".

 

[robn1]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

I've been working on this, using the HF pot. I'll take some pics tomorrow and post what I did.

 

[animefan]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Here you are, not made by me though
Just This and That: DIY Pressure Pot: Part 1

 

[robn1]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Here you are, not made by me though
Just This and That: DIY Pressure Pot: Part 1

The no regulator option is what I did, the regulator on my pot leaked like crazy. I also had the same problem with the safety valve, it would open with the slightest pressure and wouldn't close. I removed all the included fittings. I screwed a ball valve into one port and a gauge in the other. By adding air slowly, I can close the valve with the pressure right where I want it. It seemed to hold steady at 50psi, but it dropped to about 40psi over three days. It has a slight leak no matter how tight I turn the clamps. I'm not sure if I should make a better gasket, or just let it leak as a safety :lol

The tank is rounded at the bottom, so I poured some resin in to make it flat (making sure it was level first).

 

[Rebelscum]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

The no regulator option is what I did, the regulator on my pot leaked like crazy. I also had the same problem with the safety valve, it would open with the slightest pressure and wouldn't close. I removed all the included fittings. I screwed a ball valve into one port and a gauge in the other. By adding air slowly, I can close the valve with the pressure right where I want it. It seemed to hold steady at 50psi, but it dropped to about 40psi over three days. It has a slight leak no matter how tight I turn the clamps. I'm not sure if I should make a better gasket, or just let it leak as a safety :lol

The tank is rounded at the bottom, so I poured some resin in to make it flat (making sure it was level first).

You really must have a properly set safety valve on your pot. It will never leak enough to prevent a possibly horrible accident if it gets over design pressure, which in this case is easily achieved with almost any air compressor.

 

[robn1]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

You really must have a properly set safety valve on your pot...

Oh I will eventually, I'm still assembling the thing. But when I say I fill it slowly, I mean 30 seconds to reach 50psi. If I close the valve and disconnect the supply, it's not going up. And I use my compressor to fill an air tank, and work from that.

 

[robn1]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

The big problem I've noticed about the HF pot is the clamps, the bolts cut some pretty deep gouges into the lid. The clamps on the Smooth-On pot look better, the design doesn't damage the lid. But oh the price!
Smooth-On Pressure Pot for Bubble-Free Castings Every Time

While searching the webernet for alternatives, I found this paint pot from Grizzly. Compare it to the Smooth-On pot and tell me it's not the same thing with a few different fittings. The paint mixer would have to be removed (and the Smooth-On pot has a large plug where the mixer port would be), and the price is right. And it's 5 gallons!
H8226 20 Liter Auto Mixing Paint Tank

 

[Rebelscum]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

While searching the webernet for alternatives, I found this paint pot from Grizzly. Compare it to the Smooth-On pot and tell me it's not the same thing with a few different fittings. The paint mixer would have to be removed (and the Smooth-On pot has a large plug where the mixer port would be), and the price is right. And it's 5 gallons!
H8226 20 Liter Auto Mixing Paint Tank

That pot doesn't have a high enough working pressure. Description says 25-30 psi.

If your going bigger, the pot has to be pretty substantial. Finish Systems is a paint equipment supplier that has repurposed some of their paint pots for casting by taking out the stuff you don't need. I have two of their larger pots, one I converted to a horizontal tank. They work up to 80 psi, which is the pressure I use for casting clear urethane.

C.A. Technologies, Resin Casting Pots, Mold Casting Pots, Pressure Leak Testing

 

[robn1]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

That pot doesn't have a high enough working pressure. Description says 25-30 psi...

It specifically says working pressure. I think that has more to do with the operation of the paint gun, not the tank's capability. It must be at least as capable as the HF pot, and at that price it's worth checking out at least. I'm willing to bet the S-O and C.A. pots are the same base tank.

Grizzly has a smaller one too H6329 2-1/2 gal. Paint Tank w/ Gauges

 

[ThrowingChicken]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

I just put one together a couple of days ago. Still needs some tweaks, as the safety valve that it comes with caps out at 40PSI. I bought a 60PSI safety valve but at the moment it acts more as a plug/back up since I still have the stock valve installed.

I am afraid of pushing it, pressure wise, but I mostly bought it as a starter vacuum chamber and for those uses it has been wonderful.

Assuming you use the stock valve, just pick up a 3/4" pipe plug, a 1/4" cap, and a 1/4" quick connect or ball valve (or both, I suppose).
- Unscrew the paint siphon pipe from the inside of the lid, then install the pipe plug. I left the outside fittings intact and installed the plug from the inside.
- Cap one of the two available inlets on the stock gauge (or use a ball valve so you can bleed the pressure).
- Install quick connect, or ball valve then quick connect, on the last inlet.
- Don't blow up.

 

[robn1]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Thanks! I'm looking at the Grizzly pot so I'll be interested in how it works for you. I have the HF but I'm worried about the damage the clamps do to the lid. The Grizzly clamps look better.

 

[ThrowingChicken]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Oops, I meant the HF pot.

As long as HF isn't BSing about that maximum PSI then it should do fine. I am thinking of adding rubber to the lid where it clamps to prevent indentions.

 

[robn1]

Re: Any tutorials for converting a Harbour Freight Paint pot into pressure casting po

Ah okay. My HF pot seems to do fine at 50psi, but I have to tighten the crap out of the clamps to keep it from leaking. I replaced the wing nut bolts with some hex heads so I can use a ratcheting wrench, so it's a little easier.

I don't know if the Grizzly clamps are any easier to tighten, but at least they won't damage the lid.