Styrofoam

Messy but it is possible to spray candle wax over the surface of the Foam and then use Polyester resin or even Vinylester . Have to have everything warned including the air to the gun is best warmed . Take your time and let the wax harden a little and spray again and again . till it is sealed . Naturaly the resin wont stick to the wax but it is possible to cover it with Glass !!.
Epoxy is much more simple and less hassle so why bother with the hassles !!

 

Using epoxy over styrofoam seems like a waste of money me as the only reason you would chose styrofoam as a core in the first place is to save money and then you spend a lot more cash for epoxy? it makes no sense. Lets ne clear,THERE ARE POLYESTER RESINS THAT DONT MELT STYROFOAM that can be used as a first coat. Dont waste epoxy with a styrofoam core, use a proper core. I have used styrofoam as a core several times sandwiched between 4mm plywood for a hard dodger top and in a catamaran center pod build, in both cases i used WRC around the perimeter and as transverse beams, the dodger top was glued with resorcinal, the other epoxy(obviously you would not use polyester for this use.
Steve.

 

Back in the 60s CSK built a 24ft bridgedeck cat out of strip planked 4 lb density styrofoam glue and glassed with epoxy, the boat was named Foamy, she was 1800lbs at launching in january 1968 and was raced two weeks later to Acapulco with a crew of four, they were ballsy back in those days. I wonder if she is a survivor somewhere.
Steve.

 

I'm tinkering with the idea of adding a flybridge to my powercat and even though the cabin top easily takes the weight of 4+ people, using built-in furniture to provide extra strength. To keep weight down (essential on a cat) I'm looking to use epoxy glass over foam so have been searching this and other threads for ideas to keep costs as low as possible . Other than windage and residual spray there should be no real loads so was planning to construct solid sides from 70mm "goldfoam" XPS (http://www.composite-nz.co.nz/dynamicPage.asp?pageID=21) and laminate 10mm sheets of the same to form the curved front combing. For the furniture - essentially boxes glued and laminated onto the roof - the same company has a product called e-board (http://www.composite-nz.co.nz/uploadfiles/E-Board 2.pdf) where I reckon a mix of 13mm for general use and 43mm for built-in ice-chest should work well.
My questions:
a. Does anyone see problems with this as a product?
b. What sheathing (cloth, weave, mat etc.) would be appropriate and how many layers?
Thanks, Alan