I have been reading through the posts and there appears to be some differing views on the amount of pressure to pull when vac bagging your composite boards. Thought I would start a thread to get what everybody is doing in one place.
I am preparing to do my first board with 1# EPS and balsa skins. Plan on pulling 10" of Hg for the inside lams, but considering pulling more (maybe 15" of Hg) for the outside lams. Any thoughts are appreciated.
Just be careful not to pull too much Hg. The thinner the laminate, the less amount of Hg you can pull. So try and creep up on it. I haven’t tried bagging venier. I know when bagging carbon and glass, I pulled too much resin out and the laminate was too dry and did not adhere to the foam.
With 1# foam I wouldn’t go over 12 inches, even on an outside laminate. I’d keep it between 10 and 12. If you using 1.5# you can go into the 15-18 range and with 2# you can run up to about 22. Generally it only takes a certain pressure to do the job and adding more doesn’t improve the outcome. Just run it up to where you need and don’t worry about going higher. Higher pressues are just asking for trouble.
Thanks Greg. I hadn’t thought about it that way, but it makes sense.