Making dice can be a fun and rewarding hobby that allows you to create customized dice for tabletop games. Many dice makers use a pressure pot during the casting process to help reduce bubbles and create clear, high-quality dice. But do you really need a pressure pot to make dice at home? Here is a look at the pros and cons of using a pressure pot for dice making.
What is a pressure pot?
A pressure pot is a sturdy steel container that can be pressurized during the casting process. It uses compressed air to create an internal pressure of 60-90 PSI on the dice as the resin cures. This pressure forces any tiny air bubbles in the resin to be compressed, reducing the visibility of bubbles in the finished dice. Pressure pots are commonly used for casting dice, jewelry, and other resin objects.
Pros of using a pressure pot
Here are some of the benefits of using a pressure pot for dice making:
Reduces bubbles and imperfections
The main advantage of a pressure pot is that it minimizes bubbles and other imperfections in the cured resin. The pressure forces air bubbles to become microscopic so they are not visible in the finished dice. This helps create crystal clear dice with a smooth, glossy finish.
Creates consistent results
A pressure pot takes much of the guesswork out of dice making. It consistently delivers clear, high quality dice casts every time when used properly. The process is repeatable so you can reliably produce flawless dice.
Allows deeper pours
Under pressure, resin flows better and has less tendency to bubble. This allows you to make deeper dice molds and thicker casts without as much risk of imperfection. Deeper molds make it easier to add decorative elements inside the dice.
Reduces risk of distortion
pouring resin into complex silicone molds can cause the molds to flex or distort. The pressure of a pressure pot helps keep the mold rigid during casting so the finished dice retain their precise shape.
Minimizes shrinkage
Resin shrinks slightly as it cures, which can affect dice balance. The pressure from a pressure pot reduces shrinkage by forcing the resin molecules closer together. This results in cured resin with dimensions closer to the mold.
Faster curing
Some resins cure faster under pressure. The increased pressure can speed up the chemical curing reaction. This allows you to turnover dice more quickly.
Cons of using a pressure pot
While pressure pots provide many benefits, they do have some downsides to consider:
High upfront cost
Quality pressure pots made specifically for casting cost $200 or more. This can be a significant investment, especially if you are new to dice making.
Space requirements
Pressure pots take up a decent amount of workshop space for the casting process. You need room to maneuver and safely pressurize the pot.
Learning curve
Using a pressure pot takes practice to learn how to properly pressurize the pot, fill molds, place in pot, etc. Expect a learning curve as you get the hang of it.
Potential safety hazards
Pressurized containers always come with some safety considerations. Proper use and ventilation are a must. Never leave a pressurized pot unattended.
Over-curing resin
Too much pressure can cause some resins to cure excessively hard. This can lead to dice that are prone to chipping or cracking when dropped. You may need to experiment to find the ideal pressure for your resin.
Fewer open-face mold options
Resin cast in open molds under pressure tend to squeeze out and make a mess. Pressure pots generally require capped dice molds for containment. Open casting is limited.
Potential distortion
Though rare, extreme pressure levels can warp molds and cause dice distortion or mold damage. You need to find the sweet spot for pressure.
What you can make without a pressure pot
While a pressure pot has many advantages, it is still possible to make dice without one:
Solid color dice
Solid opaque resin colors hide imperfections well. You can make single-color dice without too many visible bubbles. Just avoid translucent resin.
Coated foam dice
Painting and coating dice made from foam blocks avoids the challenges with clear resin. No need to worry about bubbles.
Epoxy dice
A key benefit of epoxy is its much longer cure time. Long cures give bubbles time to rise to the top naturally. But epoxy can still have some bubbles.
Display dice
If the dice are just for display and not rolling, you have much more leeway for slight imperfections. Display dice don’t need to meet gaming standards.
Small batch production
You can certainly make a few dice without a pot successfully. Just expect more bubbles and flaws than pressure casting.
Open face molds
With care, you can successfully cast small batches in open face silicone molds without too many issues from lack of pressure.
Surface embellished dice
Adding paint, glitter, and other surface effects helps hide small imperfections in the resin from not using pressure.
Recommendations for casting dice without pressure
Here are some tips for getting the best results when casting dice without a pressure pot:
- Use very fresh resin mixed precisely. Old or off-ratio resin is more prone to bubbles.
- Let resin degas for 5-10 minutes after mixing before pouring into molds. This allows some bubbles to rise out.
- Carefully pour resin into molds very slowly and gently. Aggressive pouring introduces more bubbles.
- Tap and rotate molds during pouring to dislodge bubbles.
- Let dice fully cure in molds for 24-48 hours. Bubbles can still rise over time.
- Inspect dice and sand or buff out any noticeable surface bubbles after demolding.
- Apply opaque paints and embellishments to hide small bubbles and imperfections.
Alternative options to a pressure pot
If you want to achieve clearer castings without buying an expensive pressure pot, here are some alternative options to consider:
DIY pressure chamber
Some dice makers build simple DIY pressure chambers from PVC pipe fittings. These are much cheaper than commercial grade pots. However, use extreme caution as DIY chambers are not rated to hold high pressure safely.
Vacuum degassing
You can use a vacuum chamber to suck air bubbles out of resin before pouring molds. This helps reduce bubbles without needing pressure. Vacuum chambers are an affordable option.
Wait longer before demolding
Let resin cure longer, like 5-7 days, before opening molds. This allows more bubbles to rise gradually over time. Just don’t wait too long or molds can be harder to separate cleanly.
Slow pressure curing
Place cast dice molds in a sealed plastic container that can hold 5-10 PSI. Leave for 12-24 hours as resin cures for light pressure. This mini pressure chamber costs almost nothing to try.
Centrifugal force
Spinning dice molds on a rotating platform applies centrifugal force to push bubbles outward. Effective but doing this smoothly takes practice.
Vibration
Some dice makers vibrate molds during resin curing to dislodge bubbles upward. You can place molds on a vibrating platform or use a small vibrator.
Best practices without a pressure pot
Here are some top techniques to implement for minimizing bubbles without a pressure pot:
- Use opaque resin colors or opaque surface coatings
- Maximize mold fill time and pour resin as slowly as possible
- Let resin degas 5+ minutes before pouring molds
- Gently lower molds straight down into resin to minimize bubbles
- Tap molds on table after pouring to dislodge bubbles
- Wrap filled molds in plastic wrap to slow cure time
- Let dice cure undisturbed for 24-48 hours before demolding
- Inspect dice and sand/buff out any large surface bubbles
- Apply paints, foils, glitters, etc. to hide small bubbles
Following these reliable techniques carefully will provide the best results possible without a pressure pot.
Frequently Asked Questions
Can you make dice without a pressure pot?
Yes, you can absolutely make dice at home without using a pressure pot. However, the finished dice are more likely to have small air bubbles and imperfections without the benefits of casting under pressure. Using opaque resin colors, surface embellishments, long cure times, and careful pouring/degassing techniques will provide the best results. Casual hobby dice makers can make nice looking dice without a pressure pot using the right methods.
What can happen if you don’t use a pressure pot?
The main issue with not using pressure is more bubbles in the cured resin. You will likely see small air bubbles in translucent resin that refract light. Surface bubbles are also more likely without pressure. While sometimes minimal, the bubbles can affect the balance, appearance, and durability of dice. Opaque resin colors hide many, but not all, bubbles.
Can you get clear resin without a pressure pot?
It is challenging to achieve perfectly clear, glass-like resin castings without the use of pressure. Some small micro-bubbles are likely to be present in the resin even with careful degassing and pouring techniques. However, clear enough for most applications can be done with extra care. Using minimal dye, slow pours, long cure times, and inspection for bubbles are key. Expect a small increase in bubbles versus casting under pressure.
What causes bubbles in resin without pressure?
The main source of bubbles without pressure is air mixed into the resin as part of pouring and degassing. Air naturally gets folded into mixed resin. Trapped air pockets in the mold and resin itself are also released as bubbles during curing without pressure to suppress them. Degassing prior to pouring the molds can help reduce bubbles, but some are inevitable without pressure.
Can you make clear dice with a regular pot?
You can make reasonably clear dice using a simple steel or plastic pot without any additional pressure, but results will not be as pristine as a real pressure pot. The benefit of a regular covered pot is bubbles are allowed to rise and pop for longer before the resin cures, creating somewhat clearer resin. However, you still lack the key benefit of higher internal pressure to compress bubbles. So clarity will still be limited compared to a real pressurized pot.
Conclusion
Pressure pots certainly provide major advantages for casting clear, bubble-free dice at home. But they are not absolutely required to make your own dice, especially if you plan to use opaque resins or coatings. With care taken in pouring, degassing, curing, and finishing, you can minimize bubbles and make nice looking dice without needing to invest in an expensive pressure pot setup. Just don’t expect flawlessly crystal clear results without pressure. For hobby dice makers doing small batches, there are affordable alternatives to help improve clarity when a pressure pot is not an option. With some trial and error using the right techniques for your resin, attractive dice can be produced at home without the need for high pressure casting.