Hello everyone,
I have a 5’8" fish board shaped and ready to glass but I have some questions about the glassing. It has a stringer. I am using eps foam that has barely over a 1 pcf. That is the only foam I could find close or without spending hundreds of dollars on shipping so this is all I got to work with. Since it isn’t dense and is weak, I don’t think I should follow a typical glassing schedule.
I was thinking of doing one of the options:
2 4oz on the bottom, 2 6oz on top
1 6oz and 1 4oz on bottom, 2 6oz and 1 4oz on top
Honestly, I have no idea what I should do as far as layers go. I was thinking of other combinations of the layers but everything just seems weird. It is weak foam and I want to make sure it is strong enough but don’t want to go overboard because that would make it heavy, more expensive, and harder to make right. I would love some advice because as of right now, I have no idea what to do.
That is very low density foam. The approach that llillibel03, bb30 and and Resinhead use I believe is to add wood veneer and FG over the foam (Compsand/WMD build technology). I have never built one with this method.
However, your biggest problem will be air expansion/contraction within the resin sealed foam — causing delamination. You will have to install vents to prevent delamination.
Might want to go 3x 6oz top and 2x 6oz bottom if doing just a regular fiberglass hand lay up. 1# pcf is common in the foil world, but they are vacuum bagging with carbon
Where are you located you can’t get higher quality foam? There’s gotta be a better supplier somewhere. I don’t mean to be negative but I wouldn’t waste resin on 1 pcf.
Speaking from experience btw. I made a board a long time ago when I started out with 1.5 pcf. It sucked. However I did a vented leash plug and it never delamed and I still have it today.
Well I’m glad you’re being real about it because I am looking for advice. If I do a heavy glass coat and vent it do you think it’d be fine? I live in Arizona. Someone probably could find some better foam but from me looking around I couldn’t. I also got everything for free so far so worst case scenario I don’t lose any money I’ll just be disappointed. Do you think if I do the carbon vacuum bag thing that it would work and be fine? My board probably won’t be amazing even if it does work but it has been fun to work on and dream about. Thanks.
I’d glass it heavy considering it’ll be pretty buoyant anyways due to the foam, when I did 1.5 pcf it was very floaty. I’d spackel the board as well prior to glassing and install one of the vented leash plugs.
I can’t speak to vacuum bag method I’ve never done it but I’m sure some of the vets on here can help you there.
I did a board with this. It wasn’t easy to work with.
It delammed pretty quick. I really should have used a vent, but even with that I have little faith in it. Did a normal glassing schedule.
Then I did one with pink xps. That was a lot, lot easier, but heavier, because I didn’t lighten it with holes.
The xps was easy to bind to the glass with a pin roller.
If I were you, I’d switch to xps. If this weak eps is already shaped, remember the vent and glass a little bit heavy I guess.
Thank you cjohnnymac. This stuff has taken me on a ton more research and I’m gonna keep learning about this stuff before I try anything. I am currently agree with you that if I spackle it and use heavy glass and vent it that it would hopefully be fine. I am also looking into the vacuum bag method. In the end I’ll do what I think is easiest because I’m not very skilled with this stuff. I think I’ll be able to figure the rest of this out I just needed a direction for more things to learn about. If I mess it up bad or am completely confused then I will ask more questions but hopefully I don’t need to. Thanks again so much for the advice.
ShaperSupplyCo’s recommendation sounded solid.
You could also use S-glass instead of E-glass for a stronger shell.
Do some testing on scrap foam first.
Hey, just to throw another option into the mix, instead of a wood veneer you could use cork or a thin layer of a high density foam to ‘wrap’ the shaped blank in before glassing with a more traditional schedule. I have made several boards with sub 1lb foam, wrapped in cork and glassed as normal. They hold up well.
I’ve done many EPS boards. I stay away from using soft foam and stringers because they always end up with problems along the stringer. The softer EPS tends to tear a lot when shaping and you have to put more spackle to fill voids before glassing.
I’ve made stringerless EPS boards with 1.5 pcf and 3 layers of 8oz glass and they had quite a few heavy pressure dings on the deck after the first use.
If you live in the US, or anywhere that Balsa is available, you can buy a couple of pieces of model airplane balsa about 1/8th inch (3mm) or 1/16th inch thick by 3" or 4" wide and lay that over the stringer to keep the stringer from breaking through the deck lamination. I use use Gorilla Glue or another foaming PU glue, tape and small bricks to hold down little pieces of balsa on the foam. You’ll hjave figure out how the edges are smoothed down to meet the foam. You could route the blank or smooth the wood down along the edges. That would be a problem if you are finished shaping.
You would need a vacuum system to do a full deck covered in veneer. I usually vacuum bag (with epoxy) a full deck veneer over softer foam and it’s very strong, no pressure dents.
I have not used vents, except on hollow boards, and yes, I have had several bad delams. I think the delams on the EPS foam were due to poor work, but delams on my XPS boards were from heat.
Low cost materials will always require more work and creative ways to get good results. I think it’s best to get decent blanks if you are starting, and then get creative as you get more knowledge.
Except for the cost of the foam, resin fumes and clean up (acetone), a PU/PE build is still way easier than an EPS/Epoxy build.
Thank you all. I have a question about a potential plan.
I’m thinking that I spackle the current blank and fill in between the beads. Then I would get the 1/8 balsa wood and layer it over everything. Would it work to just use a wood glue like gorilla glue for that? I would clamp it down and apply pressure. Then I was thinking 2 6oz on top and 1 6oz of fiberglass on bottom. I would also make sure to vent it so it doesn’t delam. Do you think that would work?
Or would I have to have a layer of fiberglass in between the wood and the foam?
In my mind it seems like this plan would work and it would limit the complexity of the vacuum bag. I don’t have the stuff to do that currently and I’m not confident that I wont just mess everything up that way.
1/8” balsa would be too thick for veneering the entire surface of your blank. Shark was talking about a balsa strip covering the stringer on the deck side.
The old Bert Berger thread had the correct thickness for an entire balsa veneer cover.
