rkremser

Hello, I have never fiberglassed anything before but now am in the process of making a rc sailboat which i want to glass. I have allready created a foam mockup of the hull and was planning on glassing this to get the final hull. I was wondering if any prep work has to be done to the foam before laying the glass or will there be any big issues with covering foam? Thanks in advance

rcalfred

First, be sure to use epoxy resin--not polyester. Poly will dissolve foam. Be sure that the plug is smooth and contoured properly. Do an experimental lay-up first to learn how many layers of fibreglass to put down to get the rigidity you want. At the same time practice putting down the final thin glass and subsequent flow coat of resin to get the smooth surface you desire. Always experiment "off model" to avoid tragic mistakes! Regards.

KJohn

I have seen suggestions to use spackling on the foam to fill voids, etc.

It might be of interest to temporarily wrap sections of the hull with something like saran wrap to give it a mirror like (or wet looking) surface and use a light to reflect off of the saran wrap as you view the transition of the hull form. This might help you notice sections that need to be further contoured before you attempt to apply the final layer of fiberglass. The goal would be to make sure the hull has the best countour before you begin applying the fiberglass, eliminating adjustments after the fiberglass is applied and is cured.

rsieminski

There must be something you can seal the foam with, because I just did my 1st hull, and it sucked up the epoxy like water to a sponge. Maybe there's some foam safe contact cement, and you can put a layer of plastic on 1st or maybe a foam safe paint to seal it. Mine just kept sucking up the epoxy, and now it's grossly overweight....back to building another.

A5fly

What type of foam are you using? I usually use the Extruded Polystyrene (blue or pink) and it doesnt act like an epoxy "wick." Also, are you planning on using the lost foam method or are you planning on keeping all of the foam hull plug?

rkremser

If everthing works right i was planning on melting out the foam any i am using that polystyrene (pink) Are there any suggestions for an epoxy brand to use?

A5fly

I like to use Decomp resins (www.decomp.com). Many also use West Systems brand.

Have you considered going to a mold-based method? There are many advantages.

rkremser

What is the mold process? I am planning on only making one run of this so I'm not sure what the benifits are past multiple copies for the mold? Thanks for all the input