Fibreglass Fenders

[dodj]

I have fibreglass fenders on my Challenger. Back when I swapped a Remington rifle for my car there were no aftermarket fenders available other than fibreglass...so...that's what I got. They continue to serve me well. But recently I have noticed a few 'star' cracks in the paint.
See attached. Is this just something to sand out?  Or is it something going on with the fibreglass?
 

[Marty]

Those star cracks are from rock/debris thrown off the tire and impacting the back of the fiberglass. Common on old Corvettes. You can't sand them out. The resin or gelcoat surface is damaged and must be ground out and re-glassed.

[dodj]

Those star cracks are from rock/debris thrown off the tire and impacting the back of the fiberglass. Common on old Corvettes. You can't sand them out. The resin or gelcoat surface is damaged and must be ground out and re-glassed.

Never would have thought of that. Thanks Marty!
Is grinding out and re-glassing difficult to do properly for a first timer at the job? Probably a year or two before I do it.

[70_440-6Cuda]

I always found fiberglass easy to work with - messy, but forgiving.  Like anything else, read a lot, have a plan and take your time.  Certainly not out of the realm of DIY 

[tparker]

I don't know about fiberglass on body work, but I got some supplies  to  fix my pool. It is pretty easy, but like anything else it takes a little practice, or at least some patience. I  would imagine the actual patching should be pretty easy. Not sure about the rest. The supplies for fiberglassing pools is not cheap. Not sure if it is different that what is used for body work, probably not. I bought it at a marine supply shop and now that I think about it, I probably paid a premium on it. LOL.

[dodj]

I have short hair fibreglass filler...would you use something like that? The one I have is probably way too old to use...probably 20 years old. Don't know why I keep some stuff so long. 

[Brads70]

You posted a little while back about buying some sheet metal for down the road repairs.... maybe some steel fenders might be a wise purchase too if your funds allow?

[dodj]

You posted a little while back about buying some sheet metal for down the road repairs.... maybe some steel fenders might be a wise purchase too if your funds allow?

Maybe...but these fibreglass ones have served me quite well. Painted in '93 I think and still look good from a couple feet away. And reduce nose weight. But I might do what you suggest. I did pick up the sheet metal I was worried about. Maybe buy some '70 fenders?

[Marty]

It's a very easy repair.

In a nutshell...Grind out the star crack and scuff the area. You can go two ways. Fill with West System Epoxy resin using fiberglass matt. Finish as required. Don't bother with Polyester resin which is the most common. It will leave mapping (slight image) of your repair in the paint. I always use the Epoxy resin for my fiberglass repairs. It works on polyester and composites.

[dodj]

Mat? the star in the paint can be covered with a dime.

[dodj]

You posted a little while back about buying some sheet metal for down the road repairs.... maybe some steel fenders might be a wise purchase too if your funds allow?

Maybe...but these fibreglass ones have served me quite well. Painted in '93 I think and still look good from a couple feet away. And reduce nose weight. But I might do what you suggest. I did pick up the sheet metal I was worried about. Maybe buy some '70 fenders?

If I do that....I'd have mismatched marker lights.......so then I'd have to do some work to the rear quarters.....then I guess the tail panel....hmmm...mission creep...

[Marty]

If it's that small, just grind it out and drip the resin into the void.

[dodj]

Those star cracks are from rock/debris thrown off the tire and impacting the back of the fiberglass.

I went and checked where the star marks are. They are ALL just behind the front tire. None in front. Pretty much proves out what you said. You have been doing this bodywork thing for a while I'm thinkin'? 

[Marty]

Around 35 years up till now. About a third of that was on Corvettes. 1953-1982 with a C-4 thrown in there now and then.