guilderoy

Has anyone used styrofoam as a core for an engine hatch? Can it be used?

JRider

iTrader: (1)

I'm pretty sure it will melt when the risin hits it

Dean Ferry

Yep, just like gasoline....

Ballistic Beak

iTrader: (2)

It depends on the type of foam and the type of resin. Not boat specific but I've used foam cores for RC Air raft wings that were glassed, no melting of the foam. Surfers have been doing it forever as well.

Eps and epoxy resin are compatible as far as I can recall

Ryan

payuppsucker

I'd think some plastic sheet between the two would protect the foam from the uncured resin if there were compatibility issues.

JRider

iTrader: (1)

He said styro it will melt with any Ester resin.

payuppsucker

Hey Dean, did you get your cylinder rebuilt? The reason I'm asking is I just took two older mayfairs apart and they were a ***** to disassemble. Looks like somebody was too liberal with the red Loctite on mine though.

ren3

You should use a structural foam such as Airex or Coosa, etc.. They can be used with either polyester, vinyl ester, or epoxy. Styrene foams are generally too weak and will melt with the styrene monomer that is in polyester and vinyl ester. And, no, you do not want to put a sheet of protective plastic between the foam and resin/cloth layup as this would prevent the bonding of laminate and foam which is key to creating the strong I-beam structure. The engine hatch cover needs to be a stiff structure for obvious reasons, so it would be foolish to cut corners on laminate schedules. Do use vinyl ester or epoxy with the proper foam core as they are far superior to iso polyester.

payuppsucker

Great info, thanks for the input ren3.

guilderoy

Ok so structural foam is best.