How much pressure are you using to vacuum bag fiberglass?
I have seen information that suggests 5 to 10 psi (10.2 to 20.4 inches mercury).
For lamination with perfply and bidim i use 0,2 bars max. With close realase film, no drain in bidim, i can put a bit more. For flatter parts where i can use mylar realase film i can use around 0.5bars like for gluing sandwich skin.
On compound surface if you want tight bubble free lam you must use perf ply and bidim stretchy bag and low pressure. It’s easy to finish with a dry lam, only effective for tensil stress and no water tight layers.
Except for sandwich i only use vac bag for multilayers carbon foil parts now.
If i had time i would improve in infused lam…
Lemat,
How much pressure would you suggest for deep channels with sharp/hard angles?
I would use around 3psi and use a thick bidim to allow a good dépression spread. For those dep you need a “real” constant dep vac pump. Most home made pump system put to much pressure for lam ended to a dry one. For thin lam surfboard skin i would not use vac lam but hand lam. For channels glue fiber first with glue spray and lam with a roller.