I've wanted to try resin casting for a long time, and have finally done so a few times in the last three days. It's never been easier to do before, thanks to my easy access to CNC mills. Once I become proficient at this, I'm mainly interested in making two-sided molds for producing complex parts that would be hard to make otherwise, and casting with materials that would be difficult to machine (like soft rubbers).
I've made three silicone molds and casted two parts in the resin from one of those molds (see above). One side of the parts (the side that was in the bottom of the mold) look great, but the top is full of air bubbles. There are a few things I hope to improve in the process soon.
My first few days went better than expected, but there are definitely improvements to be made. The resin I'm using is the very well-rounded Innovative Polymers IE-3075, which has a fairly short pot life of 8 +/- 2 minutes. With the low volume of resin I've been mixing at a time, I try to wrap up in faster than 6.5 minutes.
Things I hope to change, in order of priority:
- Acquire a better vacuum pump. I think the one I'm using was broken and (maybe?) repaired in the past, but it isn't doing well. And with the cheap chamber I'm using, I simply can't degass resin fast enough.
- I need a more accurate scale for weighing things.
- Find some dedicated sheets of plastic, that have been faced flat, and smaller weights to help set up the resin parts after casting. The material I've been using thus far hasn't been flat enough, which can cause air bubbles.
- Start blanketing the bottles with canned air to better preserve them over a long period.
I feel the need to reiterate that 99% of what I've learned so far has come from the fantastic guide by Michal Zalewski. Highly recommend.
More soon, I hope!