Kevlar / Divinycell / glass laminate

I am planning to make a waveksi and had proposed a 1.7oz kevlar / H80 diviycell/4 oz glass laminate for the bottom (on a styrofoam core), bonded with epoxy resin.  Any comments on how easy it would be to work this combination, and what problems I might encounter, would be appreciated.


I would plan on at least a veil of 2 oz or lighter over the kevlar on the exterior,you need something to sand.  You can not sand the kevlar successfullywithout it becoming a fuzzy mess. 

Plan on vacuum bagging the aramid because it can float on the resin, unless you can really pull it down tightwith hand lam.

I like to bog the d-cell with thickened epoxy to prevent the d-cell from absorbing lots of neat resin, usually with phenolic ballons or milled fiber.

Good luck with the project.


Lots of  variables there.  Waveski, like a sit down with a kayak paddle type of craft?  What density of eps?  How thick is the H80.  Just 1.7oz kevlar with 4 oz. glass is thin.  Lots of flex though.  Stringer, rails, deck?  

Those materials are expensive and your going to need to bag.  You could get away with not bagging but you’d be wasting your money.

Also the waveskis I’ve seen have quite the complex bottom contours, not to mention fins.  If the H80 is is anything over a few mm’s it won’t conform to complex bottom curves in the eps, even at vacuum.  Your better going with a higher fiber content and using the H80 as re-enforcement under the ass and for the fin inserts.

There is a guy here with one leg that rides a custom waveski in pretty good sized surf.  I’m pretty sure it’s straight eps with a very high fiber content that’s bagged.  No carbon or kevlar.  Looks like 12 or 16 oz double bias biax with 4 or 6 over for a fill layer.