Pressure Pot Modification (Aussie-Specific)
The number one question I get asked by fellow Aussies looking to get started with making dice is where to source a pressure pot in Australia, and subsequently how the hell do you go about modifying it for use in dice making? I thought I'd put this handy guide together to answer all of your pressure pot questions in one place!
What is a pressure pot and why do I need one for making dice?
A pressure pot is exactly what the name suggests: a pot used for curing resin under pressure (usually between 30-40psi depending on your preferences—that's the same pressure you'd find in your car tyres) to squash any air bubbles out of your resin as it sets. A pressure pot is a dice making investment you really can't go without if you want to make crisp molds and achieve crystal-clear dice.
Okay, so where do I get one?
Sourcing a pressure pot in Australia can be tricky if you don't know what you're looking for. But fortunately for you, the local community of dice makers has grown a lot in the last three years since I started making dice and many of us have done the hard work for you in not only knowing where to source a pressure pot locally but also what parts you will need in order to modify your humble paint tank into a pot capable of holding pressure (and where to find them).
I personally have three pressure pots and none have failed me in any way so far. The first pot I purchased was by a Canadian brand called Princess Auto that I was lucky to score as an import on Kogan for roughly A$125. However in the three years that I've been making dice, I've yet to see this brand pop up again and so the second (and third) pot I purchased was actually from Supercheap Auto. You'll want to grab the Blackridge Paint Tank which will cost you about A$280 however it does go on sale 2-3 times a year for about 50% off.
If that price tag is a little much for you, I have heard good things about the brand Vevor which you can find on eBay for roughly A$130. Ultimately though you are just looking for a 10L Paint Tank, and eBay has these in varying brands, price points and qualities from as little as A$80 (based on my previous research).
I've bought my pressure pot, now what?
Now that you've bought your pot, you will need to do some simple modifications to turn it from a paint tank (designed for use with an air brush) to a pressure chamber.
The first thing you need to do is remove the internal pipe and all of the fixtures on the lid as we will be rearranging their positioning from the default. Be careful not to damage any of the fixtures as we will need many of these pieces again in our final build. If you find, like I did, that they are fixed in place with a sealant, this can easily be loosened with a heat gun... or a butane torch if they're really stuck in place like mine were. A pipe wrench and a strong relative or friend are also handy for removing the internal pipe.
Next, you will need to make a few inexpensive purchases to finish the modifications on your pressure pot. You will need the following:
- 2x 1/4" BSP Female Ball Valves - You can grab these from Bunnings for about A$10 each.
- A 3/8" to 1/4" Pipe Reducer - Found here at Supercheap Auto for about A$13.
- An air inflator kit to attach to an air compressor - I bought this kit from Bunnings for A$25 as it has 2x of each fitting plus a hose.
- Some sort of thread sealant like Loctite or this one called Loxeal (also from Bunnings) which worked well for me.
You will also need an air compressor if you don't have access to one already. From what I have seen, you can use a bike pump to fill your pot but this will be a lot more time consuming, a lot more work and all of the modifications in this post are based on using an air compressor so if you intend to use a bike pump then this guide (and my knowledge) will be of little help to you. I personally have an Ozito oil-less air compressor which you can get from Bunnings for about A$100-$150 depending on size.
Putting it all together!
Finally, you will want to assemble your pressure pot. Rather than typing out the instructions, I have included an image below of what the final layout should look like as it is pretty straight forward.
Basically your final result should have 1x ball valve on your pressure gauge that will remain perpetually closed, 1x ball valve on the other side of the gauge with the air intake connector fixed into it (to attach your pot to your compressor with the hose in your kit). You then will want to screw the pressure gauge into the smaller hole on the lid. The larger hole is where you will put the reducer with the safety release valve. Make sure you use the thread sealant on all connections and follow the directions for use (including the drying time) before you test your pot.
To test your pressure pot you can fill the pot to your desired psi and spray soapy water on all of the joints. If any of the water bubbles, then you have a leak somewhere and will want to use a little more sealant. Leave the pot overnight to see if it holds pressure for a full 24 hours as this is how long resin can take to cure in winter and you don't want the pot to lose too much pressure in that time though a dip of about 5psi or less is fine and normal.
Some final trouble-shooting tips.
If you have tested your pressure pot connections and nothing is leaking but the pot isn't holding pressure, check the rubber seal inside the lid. A good coating of Vaseline along the silicone ring will help refresh it and create a better seal.
If however your pot is holding pressure but you're finding it won't fill beyond a certain psi, try twisting the dial on the pressure gauge to allow more air into the pot. This dial controls the maximum pressure the pot will fill to and it may be too tight if you can't fill it very high. Remember to never go above the recommend safety amount for your pot, which should be about 60psi.
And finally, you always want to pressurize your molds at a higher psi than you intend to make your dice. I like to use 45psi for my molds and 30psi for my dice but as with many things in dice making, you may need to experiment a bit with what works for you.