# XPS for stringers?



## Fishtex (May 10, 2014)

PG350 said:


> Anyone used XPS foam for stringers? Any pictures hints tips? Any horror stories?
> 
> All input welcome.


Should post this in the “Boatyard” forum but if you are not using marine ply/epoxy and choose to go foam, use the proper foam, something made for composite layup, i.e. Divinylcell, Coosa, etc. insulation foams have nothing in common with real core material other than the word foam.


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## Fishtex (May 10, 2014)

Go here for some help on core materials etc. https://forums.bateau2.com/viewforum.php?f=5


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## el9surf (Dec 23, 2008)

In the surfboard world many folks tried to make xps work, whether it was a full xps blank or parabolic foam stringers made from xps. Its downfall is the foam will release gas at higher temps and cause delamination regardless of epoxy or poly resin. Maybe xps has changed but that's the issues it had in the past.


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## PG350 (Jan 19, 2012)

Thanks. Im planning on just using it as basically a form to build my stringers out of glass and epoxy. If it delaminates its fine the glass is the structure, really just a mold n the inside.


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## Guest (Nov 22, 2018)

PG350 said:


> Thanks. Im planning on just using it as basically a form to build my stringers out of glass and epoxy. If it delaminates its fine the glass is the structure, really just a mold n the inside.


How tall do your stringers need to be? There are other ways that are better than xps!


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## PG350 (Jan 19, 2012)

Boatbrains said:


> How tall do your stringers need to be? There are other ways that are better than xps!


Not exactly sure yet to be honest. Still have the boat flipped and working on bottom. Im hoping to have enough thermo lite board for the stringers but im not sure yet so looking into other affordable options. When I get into it more I will probably take pics and ask for more suggestions. Thanks for the help and HAPPY THANKSGIVING.


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## Guest (Nov 22, 2018)

I’ve use vinyl gutters for temp molds and made glass stringers and just left them hollow before. Two layers of 18oz woven with a layer of 1.5oz csm in between. Then pull the gutter out and trim part to fit hull. Glass in with two overlapping layeres of 1708biax and viola! Works pretty good in these small boats. The cores you mention have zero structural strength so this would be just as good being hollow.


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## Guest (Nov 22, 2018)

I also assume you are doing a floor and decks? Look into nida core for those. It is pretty cheap and good stuff when used properly.


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