Hello old friends, longtime no see. I’m just popping in after a decade, for some advice. Having given up board building about 10 years ago I managed to get sucked into it again, mainly as a mentor to a friend with boundless enthusiasm and a few GG’s to spare. My last builds were Bert style balsa over EPS which are still going strong and I’m comfortable with that build.
I am curious about innegra, I had a coil and while it was good it was no sunova or McCoy I found it too stiff for my liking. I was thinking about a balsa railed board with 2oz innegra and 6oz eglass on top with 2oz innegra and 4 oz glass on the bottom.
Any thoughts on this schedule or should I sandwich the innegra in glass?
Also any tips on using innegra in particular the amount of resin to get it to stick to the blank? Obviously I will be vac bagging it.
Innegra is 1/3 the weight of fiberglass. 2 oz. is equal to 6 oz. in it’s ability to soak up resin. I found for wrapping rails it goes on pretty easy when you cover it with regular glass. I don’t know why you would need to sandwich it. Vacuuming is good for getting it to lay flat and save weight but that’s true with any fabric. Can’t comment on the schedule unless I know what core your using.
Sounds fine on the schedule. Sometimes I’ll use spray adhesive to hold the innegra down. I spray the tape when I cut lap to keep the spray from coloring the foam if I get it on too thick. This may or may not be any easier as it’s a pain to wet out when its already laying down on the underside.
I’ve done a few boards with innegra, always under vacuum. If you sandwich it with 3oz like I did you end up with a weight similar to 4+4+4. In other words, not light. It does seem to be bullet proof and it does look cool, but it also seems grossly overbuilt. If you thought coil was stiff that’s nothing compared to an innegra snadwich.
If you’re not going to sandwich it you might as well just stick with a normal wet lam of S-glass. IMO
Thanks, I didn’t understand that it soaked up resin that much. My idea was to do the deck and bottom with innegra, but not the balsa rails which would be glassed over.
I think I’ll stick with the Balsa compsand construction and avoid the innegra.
Would 2lb eps survive without a sandwich and only glass , how well would it support fin boxes (FCS II or probox) without divinycell support.
When using 1.5# or 2# we usually install the side boxes directly into the eps, and I think they take more strain than the center boxes. I’ve taken to using PU inserts that I scavenge from old singlefin longboards that use the denser foam. I do that more to control for the leak factor around the box, although I think it also helps to stabilize the box.
I’ve done a couple boards where I glassed one side of the material I’m using for the insert with a few layers of 6oz, templating the plug and routing a 3/4" or 1" deep cavity in the blank for the plug. Then I glue the plug in face down where the fiberglass side is at the bottom of the cavity. I do this before i even template the blank. Shape and glass as normal. That way when I rout for the finbox or plug itself it’s going through that bottom layer of fg, further stabilizing it. That bottom layer basically forms a flange at the base of the box as well as the stabilization that occurs in the exterior glass job itself. Within reason, that box basically won’t rotate under torque.
I got the idea from Robin Mair’s design of his boxes where he moved the bottom of the flange down the side of the box itself a little to create that truss action. So hat-tip to Mr Mair for that.
This board has 2oz Innegra on the deck and over the rail. the bottom is innegra also but does not lap over onto the deck. Therefor there is only one lay of 2oz around the rail.
it’s a PU blank laminated with Epoxy + Epoxy filler and straight sand. No tail patch or any patches of fiberglass…
just a throw away experiment.
The flex is awesome, it really goes good, Loads up in and out of turns great.
It’s real beat up-my go to board for the past 4 months or so…
I’m super impressed with how it’s held up being literally only wrapped in one layer of 2oz innegra.
Also I shined the rail pretty hard it dented pretty bad but no crack at all.
Myself and the crew at work agree that it’s held up way better then expected.
A 2oz innegra deck with 4oz ( whats it called) mmmmm oh well… fiberglass on a 45 degree… (quad axle glass i think) over it, with a 2oz innegra bottom. And a stringerless EPS Blank.
I like the sound of that.
