Fiberglass basics - Ack! Your tips needed
 

Hey Guys,

I would like to learn how to do fiberglass for automotive use. In particular, my long-range plans are for a full aero-cap for my pickup truck

I really know absolutely nothing about fiberglass, but for me, sometimes it best just to try something. Yesterday, I picked up some 3M brand resin, fiberglass cloth, and rubber gloves, and then did a little test fiberglassing today over some foam.

(You can read about that on my blog.)

So far, I've learned that fiberglass eats foam and it is terrible sticky! (Smells bad too!)

Any good general tips for working with fiberglass? If you know of a good book or on-line resource, please let me know.

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Not much personal experience, but I posted this as something hopefully informative.

Polyester resin (AKA "fiberglass resin") eats foam. Epoxy resin does not eat foam. Polyester resin stinks. Epoxy does not. Epoxy costs four times as much.

Google "Gougeon brothers book" for a free PDF on wood and fiberglass boat construction. The Gougeon Brothers manufacture West System epoxy, the stuff that I used to seal my topper.

An aero topper is really a funny shaped boat installed upside down on a truck. The main difference is that the topper keeps out water falling down from above.

Polyester (fiberglass) resin eats styrofoam, but there's a foam it doesn't eat - urethane? Of course, the urethane foam is more expensive and less commonplace, too. Yes, super sticky. Either acetone or laquer thinner will cut it. - Either epoxy or polyester.

I downloaded the Gougeon Bros Book.
400 Pages!?

Ok, I'm sure to ask a few more questions here when I'm done with the book.....
in about a month!

I found a forum on building from-scratch movie props and replicas, where a lot of the guys have been building all sorts of things from pink foam.

Some of them have had success with fiberglassing over pink foam by first sealing it with latex paint.

I have some "junk" latex paint kicking around, so I slopped some on the back sides of my test pieces before going over to the relatives for Thanksgiving dinner.

Hopefully, when I get back, it will be dry, and I can do "fiberglass test batch #2".


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Hey, look! This is my 4000th post!

One technique I have used is to stretch polyester cloth over wire frames. It acts as a mold. My minivan has photos of the wheel skirts I made for it in this way.

I used to use west bros epoxy but became allergic to it and now get my epoxy from US composites. It washes off pretty well with soap and water.

I've heard of the polyester cloth trick. Glad to hear it actually works.

Sealing that foam with latex paint DIDN'T work. The fiberglass resin still ate right into it. I only used one coat of paint, but it was pretty thick.

Maybe multiple coats are required, it was pretty cheap paint too. I don't know if that made a difference.

The only reason that the pink foam was eaten into, it that you probably used POLYESTER resin to wet out the cloth. You mentioned the smell as well, and this again indicates polyester.

Now if you use EPOXY resin you will find that the pink foam it is not attached, and in fact the mixed epoxy has virtually no smell as well.

The epoxy is about three to four times more expensive, but allows you to do a very nice layout without the smell and shrinkage of polyester.

I can recommend West System Epoxy as well as U.S. Composites epoxy. Both have given very good results.

Read through my fiberglass tail extension project. All the questions you have asked above are covered there....

http://ecomodder.com/forum/showthrea...ect-13533.html

Jim.

Polyester resin does not eat through urethane foam. (It's a yellowish-tan color, rather than the pink or white of styrofoam.) Couple of other advantages, too. One is that you can build up areas with urethane sealing foam ("Great Stuff" is one brand), another is that it bonds really well with urethane glue ("Gorilla Glue").