Hello.
I'm a relative novice at casting resin parts (from silicone molds), however I'll be needing produce quite a few parts soon, so I was thinking of purchasing a degassing chamber and vacuum pump.
But I have a few questions involved in this:
1. I know about degassing silicone, but is it ok to de-gas resin that's already been poured into a mold? (to avoid bubbles in an intricate mold)
2. If question 1 is fine, would it be ok to use Easy Composites' 26L Degassing Chamber for a small piece as well? (say around the size of a golf ball)
3. Generally speaking, what is the minimum wall thickness I can produce with EC's Fast Cast Polyurethane

Many thanks to anyone who can help with any of the questions.
AVA

Hi AVA,

Thanks for the post. Answers to your questions as follows:

1. Yes, you can certainly do this. It will only be effective if the resin has not yet started to gel/cure so for more reactive casting resins (like Fast Cast) you would need to pour your casting and get it in the degassing chamber very quickly. It's worth noting that for something like our Fast Cast degassing is not necessary but for other casting resins like our Waterclear Polyurethane Casting Resin it will really improve the quality of the casting.

2. Yes, absolutely. If you're only ever going to be making tiny castings (and therefore only ever tiny moulds) then in theory you could even degas inside our Resin Infusion Catchpot but, considering the fact that silicone will often expand by 2 or 3 times their original volume during degassing, it's probably still worth using the larger, dedicated vacuum degassing chamber.

3. This really depends on the shape of the piece you're casting, certainly 0.5mm should be perfectly possible, providing you de-mould it carefully. The Fast Cast really is a great material capable of reproducing incredible details whilst still being really easy to use.

I hope this helps and look forward to working with you.

Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Thanks Matt.

one extra remark, If you have a 2-part mould you'll have to watch out while degassing, Like Matt said your resin will expand while degassing, that may cause your mould to dislocate or pull out some resin so your part wont be filled with enough resin anymore.

Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com

Thanks Matthieu.

Hello

Do what Matt says and I will add one more thing.

If you have a paint pressure pot put the whole thing in before it cures and use a pressure of about 30 psi ( experiment maybe 15 psi will work I have gone to 50 psi). This will reduce the size of remaining air bubbles to the point of being invisible.

Fred     

hmmm i suppose one could vac down the resins before pouring and again after. the cure speed is really the factor .

CarbonFiberCreations