Talk Composites - The Forum for Advanced Composites

air coming through mold?

http://www.talkcomposites.com/Topic14667.aspx

By jaffa - 1/19/2015 4:01:19 PM

Attempted my first infusion today, doing a car boot so maybe a bit ambitious! Got as far as -25 on the vac gauge but couldn't get it to stay, but couldn't hear any more leaks after countless laps around the part.

I swallowed a brave pill and decided to infuse, hoping some bubbles would highlight the problem that I could then quickly fix.  Anyhow,  one side was perfect, the other side of the part looked like it had a water feature inside from the number of bubbles!  Turns out they were coming through the mold, attempted to patch with gum tape but no real success.

I let it all infuse through just to finish my learning and will demold tomorrow and try again.

So I've learnt lots from this, now know how long it takes to infuse (30 mins) and several other things as it's quite a complex inner skin that I'm working on, before doing the outer skin.

Any ideas as to

1: what's caused it, it was made with unimold system. Guessing I wasn't diligent enough with my bristling in that area
2: best way to fix for round 2, do I just cover any sharp bits and envelop bag the whole thing?

All help appreciated
By VVS - 2/21/2015 4:43:41 PM

I'm very new to moulds etc but found a simple work around was to cut and attach a piece bag to the back of the mould in the same way you attached to the front, found this a little easier than bagging the whole thing and can just leave it attached after.