Plywood stringers and EPS

Hey Guys

Whats the best method of obtaining plywood and or any other wood and gluing it up with EPS blanks??

Now I know a lot of guys will tell me about PVC stringers, but I just like the look of wood.

I haven’t even seen PVC anywhere. (I haven’t really looked though)

With plywood, do I need a certain type of ply like marine ply???

Can I go to the hardware store and buy plywood already glue?? I’ve seen it in single, 3ply, 6ply etc.

or do I have to glue them myself???

If I should glue them myself what glue should I use??

Also what glue should I use to glue it to the foam or should I use epoxy??

This is an area I know nothing about so that why I ask so many dumb questions

Any info not already mentions would be much appreciated.

Cheers

I just go to the hardware store and get 1/8" birch plywood and glue it up to the blank with foaming ployurethane glue. make sure you spray a little water on the wood first, this helps it foam up more. and tape off the edges of your blank to keep excess glue off the deck or bottom.

othres recommend luan doorskin, i have never tried it. i use the birch because it is cut and made locally.

for PU glue, there are a number of different brands but I find gorilla glue foams up and fills voids better than the cheaper kinds. you could also use epoxy to glue it up but this makes it harder to sand out during shaping.

cheers

hey mds

imo

the amount of glass you need to make a dent resistant eps board

kinda makes the stringer unnecessary

3mm plywood is way overkill but convenient cuz its in a sheet

just 3mm of balsa will do

or 3mm pvc High density foam

i use paulownia window blinds, they can be cut with a craft knife

check out this thread to see how easy it can be

http://www.swaylocks.com/forum/gforum.cgi?post=285070;search_string=silly%20method;#285070

For longboards ply stringers can be useful I make mine out of 3-4mm marine ply, I have used wood glue to glue up and that worked fine, as silly says, the amount of glass coming on top sorta takes care of many structural issues, mostly I brush epoxy on the stringer for the glue up though. To avoid the sanding issues, I ensure my stringers are 99% finished to my design so I have minimal planing and cleaning up once the blank is glued, wood next to foam is a b$tcH to scrape without gouging foam. I have also made ridiculously thick ply stringers, as a “project” I made a 19mm Meranti ply stringer for a 6’6" fish, it was a helluva job to make that thing flush with the foam but it worked out ok and the board looks cool and works too, no flex in that tail eh…

A bit of advice, get a good set of spokeshaves for this task, you can’t do it without 'em as the plywood is essentially planks of wood with grains in all directions, only the spokeshave can clean that up without tearing it all to shreds in my experience…

What if you glued single sheets of plywood together with all the grain running in the same direction???

Cheers

have made about 10 boards so far with just 1/8" luan ply, and no problems at all.

like was said above, just get it as close as possible to your desired foil, and bend the foam to suit.

i also use foam pu glue, as it does sand a bit easier.

You can glue wood to EPS with white glue, Elmers type. you don’t need to spend the extra $$ for the fancy glue. You need fancy glue if you are going to glue PVC to EPS. White glue will hold no problem. I’ve done my perimiter stringers with white glue and it holds really well, and thats a lot more presure the just a single straight glue up.

Use birch bender ply for your stringers. It’s grain is a lot more directional for the use in stringers, and it a bit more light weight. Also If you are looking for PVC, do a google search for Foam PVC. Foam PVC is what you want, and if they make business signs in your part of the world, then they will have Foam PVC…and it comes in all sorts of colors too.

It sounds like your looking for a more classic looc. If that’s the case just get a piece of redwood of basswood.

The whole thing with PVC isn’t about the way it looks or trying to fake the look of wood. The PVC is about the way the board surfs. It’s more flexible and durable than wood, and therefore makes a much livelier board. I guess it’s all about what your looking for in a surfboard?

I haven’t broken PVC board in half yet…but I’ve buckled a few.

Hey thanks for all the info guys.

I am going to to check out a timber store called “mister plywood” today

Bound to have something there for the job.

Cheers

PS. By the way, what do recommend for longboard and SUP boards??

I was the same, wanting to get that classic look, but in the end I opted for stringerless.

When you are using EPS there are a few other factors you need to take into account.

If you are using a lower weight EPS then you will probably need to put in a air vent. If you use a stringer then you will need to either put in 2 air vents or drill holes in your stringer to allow air to pass between sides.

If you are using heavier EPS then you don’t need a vent.

This is all debatable and some people believe venting is unnecessary.

I have also been advised that though epoxy is very strong it scratches easily and so it is advisable to paint over the outside of the glass with a protective paint layer. This also protects the resin from UV rays which can damage the epoxy after a while.

When taking all this into account I just thought bugger it I’ll just go stringerless for the first one.

Which is a fish with glass on keels.

If you do decide to go with the stringer then Mr plywood should be able to sort you out and I got some foaming polyurethane glue from Bunnings. Sorry can’t remember the brand. I haven’t used it yet but it sounds like the same stuff all the other guys are talking about.

Cheers,

JD

Quote:

What if you glued single sheets of plywood together with all the grain running in the same direction???

Cheers

http://en.wikipedia.org/wiki/Plywood

I’ve had great results with PVC foam stringers, too. My personal choice these days, but because wood looks so good, and people are so used to seeing it, I’ve done a few boards with the foam stringers stained to look exactly like wood.

If you seal the foam sringer well when you seal the blank, and sand it smooth, you can tape off the foam on both sides and use different shades of glazing to imitate wood grain. The glazing I use is for antiquing furniture. I’ll take at least two different tints, and put them on a fat, round brush with a coarse tip. Then I’ll drag the the tip of the brush down the length of thes stringer, kind of rolling it over from side to side as I pull. The result is a smooth, streaky, wood grain look.

I’m currently making a 6’8" shortboard/funboard and I made my pre-rockered stringer out of pine. It was only $10 for enough wood to make 2 stringers 1/4" thick (the board was 8’x6"x1"). As for glue Elmers Pro Bond wood glue worked fine for me.

With a good eps foam core and solid glass job, stringers arent necessary.

They benefit mostly the shaper/builder.

Dont believe me? ask Bill B.

R. Yater was explaining to me how Midget makes his plywood stringers with the center piece on a diagonal instead of perpendicular. The reasoning was strength with proper flex characteristics.

Is this correct Midget?


sorry Mr. DS, just being respectful.

“Mr. Yater”…wow, it reminds me of the first time someone called me “sir”…hated it, cuz then I knew I was getting old.

Oh, this about stringers, right…ahem, as far as strngers in EPS, when you pearl the nose and OMO (Our Mother Ocean) takes a big dump on your board, it will be the stringer that breaks instead of the foam flexing and rebounding. Doesn’t matter how the ply is angled (sorry Midget).