Laminating wood directly onto EPS?

General Discussion
1

With my last board I laminated a 2oz/plywood/2oz skin onto 1 lb EPS. The board came out kind of heavy which was OK, it being a gun.

My next will be a daily driver shortboard and I’m trying to think of how to save weight. One thought was to eliminate the 2oz between the foam and ply (1/8" bender ply). Can I lam the ply directly to EPS? My intuition is that any failure would come from the EPS separating from itself (the blank disintegrating), not from the ply separating from the EPS.

Anyone ever try a compsand without a layer of glass beteen the EPS and skin?

I’m not worried about skin strength because the ply is plenty strong. In fact I’m thinking of thinning the ply (which is 3 ply) by shaving off one ply.

Thanks for any input.

2

I’ve done both veneer (1/32") and Oneula’s woven bamboo directly onto the foam. Used epoxy for the veneer & foaming pu glue for the 'boo. Neither one saved any weight, nor would you skipping a layer of 2 oz. If you want it lighter, you have to use something other than the ply…that’s your heavyweight, not the cloth.

3

I did a layer of 1/16 balsa over home depot eps with elmers glue and blue tape (as clamping mechanism). Two years later, no problems and no pressure dings.

4

I’m with Ben

To each his own but it would be a waste time laminating ply over foam

ply usually is used as a skin for hollows where you need that amount of thickness, strength and stiffness.

Been toying around with the idea of bringing up some sheets of the woven bamboo when I come up next weekend to see Keith folks. Since it’s around $40.00 a 4x8 sheet I can’t really bring up and give away a boatload of the stuff. But I can bring a couple sheets or so for folks to try. It’s 1mm fairly light and pretty simple to work with compared to ply. You just cut it with tin snips and sand off the shiny finish before laminating or gluing it on. Unfortunately it’s stiff as steel once glassed and a b*tch to trim and sand the edges as it shreads against the grain…

But Ben’s found ways around it.

I’m moving on to other flatter straight cut versions of the stuff everyone else is using but still like to use this stuff as a deck patch (because it’ll never pressure) or bottom when I’m too lazy to tape up some balsa strips. It works better as a full sheet on the bottom than with the compound curves of the top but you know that already working with a full sheet of ply for the top…

I think Dan B has a sheet or two as does Jarrod.

It’s not made for surfboards it’s a decorative wall covering used everywhere here

but hell neither is plywood

and since my bro and I are using lowes roof insulation for blanks anyway it’s a one stop at HD/Lowes.

It does looks nice and there’s a diagonal cross weave like crossweaving your glass at 45 degrees so if you think about the crosswoven bamboo laminate sandwiched between a layer of warp glass under and over it you’ve got a pretty interesting composite skin. A micro version of Roy’s technique as a skin versus a hull structure…

My mental brother just did a HD foam hull with luan ply for the bottom skin (due to laziness again) and was amazed at the significant increase in weight compared to either the bamboo or balsa versions. Probably won’t do that again.

5

technically speaking it wouldnt be a compsand without the inner glass

6

LLilibel03,

The objective in using the wood when lamming is to create a sandwich skin, which is 2 layers of fibreglass separated by ‘something’ around 3mm thick.

Using wood, you can leave that ‘something’ sandwich core uncovered by any cosmetics. And you improve ding resistance, of course.

If you eliminate the inner glass layer, you’re using wood only as cosmetics.

7

1/8 inch is very very thick when your using ply.

I did one with with 1/16 gaboon 3 ply, and it was basically bullet proof, with only very light cloth inside and out.

It was not really too heavy, definitely still lighter than a pu/pe.

It would be the equivalent weight of using about 3/16 thick balsa.

The difference is, to get the lighter weights you’d have to sand the ply down even thinner than 1/16.

So then the thickness of your sandwich panel is very small, and the advantages of doing sandwhich construction are changed…

Not necessarily diminished, but how it performs changes, flex, strength, springback, etc etc.

Theres so many combinations for materials and thicknesses, trial and error, trial and error…

Kit

8

three ply wood is already a sandwich!

no problem without cloth

but, the inner cloth control/holds the resin quantity

the main problem with ply is weight and inability to bend around compound curves

9

yes it is a sandwhich

but it doesnt make it suitable for a high perf compsand

you could call a piece of cardboard a compsand if you like

i can call my penis a firewire

or it was after a one night stand i had in ma twenties

10

HA! Yeah my d_ck has been called a firebreathing dragon at times!

Hey I’ll bet you thin 3ply would make and excellent hiperf compsand.

The issue is the finished weight.

Anything is possible with comps.

11

it would certainly be ding proof

i guess i havent yet seen a product that would be suitable

i cant see the point when other then convenience of having a full sheet

in which case i would go with dcell corecell plus thin veneer option

id rather add weight with glass on the outside thanks

12

Not only is glass + 3 ply a sandwich, I was really thinking that the ply/blank/ply is the sandwich. A board a little over 2" thick is not a whole lot different that a composite sailboat hull/deck panel that uses a 1-1/2" balsa core, is it not? My real concern is when flexing will the ply pull away from the EPS easier than glass? Would it help to seal the EPS with epoxy/cabosil?

I’ll mention that when I say my fun gun is heavy, that is because my last two boards were eps/epoxy shortboards (very light). When I let someone who is accustomed to riding longboards hold my board they are not concerned. I guess the weight is more like a traditionally glassed longboard. Maybe I’m just not used to riding an 8-0 x 22 x 3!!

The strength is phenomenal! After 6 months of continual use there is not even so much as a hint of a pressure ding. That was why I got into the whole board making process in the frist place- I would destroy boards with my bony knees is 6 months. It was getting too expensive.

Finally, I guess the aesthetic aspect is very important to me. I was blown away by Daniel Hess’s boards and that is the “look” I’ve been after ever since. His process seems pretty secret so I don’t know how he gets the light weights he does, but I’ll settle for anything that’s rideable, coupled with the beauty and strength.

Oh, and after riding my heavy board and having SOO much fun on it…I’m not so convinced that super light is always the better ride…

13

http://www.hesssurfboards.com/concept.html

14

With 1/8 marine ply, you could do away with glass on the inside and outside, and the board would still be the hardest thing around. Except your rails would fall off!

As Benny said, leaving out glass layers will save you next to nothing in weight,get rid of some of the wood.

Resin will adhere fine, but cloth stops the resin from disapearing into the foam or wood so much, so you insured of a perfect bond.

I’d expect you to use about 3 ounces of resin minimum to stick the veneer down - instead, use that 3 ounces to wet out some cloth (2oz cloth), your only adding another 3 ounces, and the layer of cloth distributes the resin more evenly.

Not to mention the strength gains… using resin by itself is a waste, basically, it’s non structural.

Those skins probably weigh 30 - 40 ounces combined!!!

You’ll get much greater weight savings by getting rid of some of that.

Although shaving off ply might be a hassle.

You could do it with your shaping electric planer pretty well. I say go for it.

I’m all in favour of using whatever stuff you’ve got lying around, make something and see how it rides!

I just finished my latest one, this is cobbled together from all the skanky scraps of paulownia that were too sub-standard to use on other boards, and some offcuts of Pacific Rimu that were left over from some archatrave I was putting up the other day for a lady. Great to put the “scraps” to some use!

Kit

15

im under the impression that 7 to 8 pounds for a compsand fish (around 6 ft)

is heavy

and most likely stiff

all the things a compsand are not or shouldnt be

theres no secrets

its all there in berts original post

no secret???

its a sandwhich on a sandwhich

with light cores on both the board and the skins and glass between

it doesnt get any more simple