Dravis (25/11/2014)
The big difference between using high pressure and high vacuum is what happens to tiny amounts of gas left in the resin/laminate .
A trapped bubble that would be microscopic under high pressure will be clearly visible in vacuum ...
So: If the tiny outgassing from the resin can not be moved away by the vacuum -- you get pinholes -this is why you need a good breather layer, perforated release film and a slightly resin-rich layup, before vac-bagging it.
De-gassing the resin before use also helps.
Thanks for your time and help.