so I’ve heard several times that a drier lam is a stronger lam. There really truth to that? -I mean, say you have a 4 & 6 schedule and the resin wets out, everything good and by the book, but then you notice there’s a heavy texture on the 6 fabric after cure, i.e., you need to either shoot a serious hot coat or sand into your fabric. I don’t sand into the 6, I add more resin. I mean, I paid for that fabric, why would I to delete it…
This talk of ‘dry lams’ sounds odd to me. The resin wets out at will. If the board needs more you add more. (for all intensive purposes, let’s assume blank is sealed sufficiently). So, when someone touts their lams are dry, what the hell does that mean?
High Fiber ratio is really important for tensil resistance. But surfboards break by buckling, flexural instability of compressive stress, where high fiber ratio is not as important. A sealed lam is more important for durability of blank…
With vacuum bagging it is actually pretty easy to get the laminate too dry if you use too much vacuum. You’ll see it as a whitish haze or scattered white spots when you remove the peel-ply.
On a normal surfboard, less than three layers of relatively light glass with no sharp curves or angles, you are better off putting on a nice, tight hand layup than going through the expense and waste of vacuum bagging.
A skilled hand laminator can get really close to the ideal 50/50 glass/resin ratio. With this type of a layup, you will see all of the weave of the fabric before you do the fill coating.
Where the vacuum bag is really useful for surfboard construction is in applying sandwich skins.
A properly wetted out lamination will produce a coarse texture on the surface where the weave is very evident, yet fully saturated… The whole reason for a sanding/hot coat is to fill that texture and result in a smooth surface after sanding. If you load so much resin into a lam that the weave disappears you are wasting resin and will get a weaker, more brittle glass job.
( I had to laugh at “all intensive purposes” Too funny)
Norm was a damn funny guy. Sad thing is, I know a couple of guys who speak like him, and it’s not for comic effect.
Stuff like “maligned” when they mean misaligned. “Paralyzed”, when they’re talking about making something parallel. And my favorite… a “phalangic” shark, when he meant pelagic.
