Fibreglass confession

[Metallisomething]

I need to confess I don’t own an RV. My knowledge of fibreglass is what 3 hours of research has taught me. This forum seemed to be the place to ask so please be kind...

I just bought a used spoiler for my car. It is a saleen wing for a fox body mustang and it is fibreglass. I’ll link a photo of a car that isn’t mine with the spoiler on it.
I’m not looking for a show piece but would like to do a decent job of repairing some long cracks on the lip. Probably 8 inches long but narrow all the way through to the hollow space inside the wing. Almost like a seam has come apart.

I was looking at bondo glass (short hair) or bondo hair (long hair). Using fibreglass sheets and resin would probably be best, but can that be sanded flat for a seamless repair? Most online tutorials are for repairing bumpers etc where you can apply the material and resin from the back where it won’t be seen. I don’t have that option for the spoiler though. Every accessible surface is smooth. Which is why the glass/hair option seemed the easiest for seamless repair.
Thanks!

Picture:
https://sep.yimg.com/ay/yhst-59923783762737/1979-1993-mustang-saleen-hatchback-spoiler-5.jpg

[David Tilston]

Take a look at this thread:
http://www.fiberglassrv.com/forums/f...ass-52498.html

[John in Santa Cruz]

me, I'd ditch the spoilter and any Saleen logos etc, and make it look as much as possible like a dog base mustang. sleeper!

[Metallisomething]

Originally Posted by David Tilston

Take a look at this thread:
http://www.fiberglassrv.com/forums/f...ass-52498.html

Thanks David! This seems to be the ticket.
Any opinion on using bondo glass or bondo hair vs using mat and resin?

And John, I’m not into body kits or crazy cosmetic stuff but I’ve always liked the saleen wings. Other than that my car will look (and be) stock. And it’s not that fast either!

[charlsara]

You can certainly repair fiberglass. However to get a totally smooth repair takes training and experience. I doubt that will happen on the first repair. I once had a job repairing fiberglass truck hoods. I got good at it but it takes patience and skill that has to include hands on training. Take it to an auto body shop.

[stevebaz]

If it were mine I would get a Can of Duraglas. The crack you want to fix I would open it up a little by grinding a V in the crack. Then open the crack with a wood wedge.

Then mix up the Duraglas and over fill the crack pushing the material inside as well a puttying over the outside. When you remove the wood wedge material will squeeze together and squeeze some on the outside as well as inside. This will lock the repair together. Cover the repair with plastic wrap and let it cure.

After cure you can power sand into shape. Wear safety glasses and dust mask.
Once you get it to shape any minor imperfections can be filled with Bondo and sanded , primed and painted.

[Metallisomething]

Thank you so much everyone for your advice and willingness to share your knowledge despite me not being and RV owner.

Stevebaz, my cracks are narrower than that but probably just as long. What you posted looks like the easiest solution, that's what I'll try first, instead of buying mat and resin, like the above linked tutorial thread shows.

charlsara, I'm not looking for a show piece, so I'm going to give it a shot myself. I have patience, hopefully that will serve me well.

[Mike Magee]

Tiger hair is a similar product, I think.

[charlsara]

OK. When you are sanding it is easy to sand off to much. Fiberglass will not have the resistance of metal.