Research – Casting with Resin

Reading up on what to consider when using resin.

Releasing agent required where mould has potential to stick to resin.
Sample using Latex mould, however silicone rubber moulds will be stronger for repeat moulding.
Matt silicone moulds will give a matt finish – gloss silicone moulds a glossy finish
Casting moulds are better quality and more durable than baking moulds.
Read the instructions to know for sure what quantity of resin to mix to what quantity of hardener and how long it takes to cure
Be super accurate with measuring
Mix thoroughly – looking for a uniform colour
Choose the right resin
Get good at the basics first

Epoxy resin is:

best for beginners as it is the easiest to work with.
Has the longest shelf life
Most forgiving environmentally
Longest pot time
Sometimes cures with a yellow tine – check before you buy – the more colour free the more expensive.
Available as a doming resin which is thicker with extra surface tension, however more difficult to remove bubbles from.
Considered a soft resin meaning the casting can be dented.
Not suitable for polishing with a polishing wheel – it will not withstand the heat.

Clear Casting/ polyester/polyurethane resin

Generally cheaper than epoxy resin
Cures very hard with the hardness and clearness of glass
Can be polished with a buffing wheel and compound
Does not require recoating or a gloss spray to be shiny
General moisture insensitive – not affected by humidity.
Requires lots of ventilation.
Short pot time – generally 8 minutes – less than epoxy resin
Careful calculation of resin to hardener required (so many drops per 100ml)
- Thin layers require more hardener to generate more heat to cure
- For multiple layers, each layer adds to the heat effect meaning each layer requires less hardener than the one before.
Be aware of the end result at the beginning – measure the right amount of resin and hardener for your actual requirements.
Shelf Life is no more than six months which epoxy will last much longer.
Exposed Surface remains sticky after the resin has cured. This can be sanded off or sealed with resin sealer.
Likely to break if dropped.

Bibliography