Getting fiberglass fenders to a presentable finish

[tdskip]

Good morning - looking at a car with front flared fenders in fiberglass. I know the answer is "it depends", but for driver quality paint these shouldn't be prohibitive to get sorted out, will they?

Panel fit, and related bumper fit etc, is the bigger issues than paint, right?

Anyone been there, done that, and survive it?

[dfhtrhjn]

I put fiberglass bumpers, fenders, frunk, and decklid on my race car. It was hard to tell they weren't steel. The paintwork was indistinguishable from the steel parts, you had to look under to see.

You'd need to fill/grind the edges to make the panel gaps look right; there's a well established technique for it you can lookup. Then skimcoat and sand a couple times to get surfaces smooth and straight.

[tdskip]

Thanks Steve

[wayner]

Mine bolted right up, almost perfect surface out of the box too
(MA Shaw)

My front bumper needed a lot of work (GT racing)

[tdskip]

Thanks Wayner, man she looks good/mean.

[jpnovak]

That is a bumper problem. Looks like it was not mounted/fit correctly. Also looks like NB bumper on flared fenders.

[wayner]

Thanks Skip!

[wayner]

I tried to find pictures of my front bumper under construction.
If I find them Ill post them but, essentially took cuts out of the bumper in some places, and used metal foil tape as backing to build new fiberglass on to fill the few inch gaps that were needed.

Next, once it was all one piece again, took curf cuts out of it in order to expand the profile of the end of the bumper to meet the flare exactly properly.

Again, created new fiberglass in between


(also, note that the factory SC-CR car had a bumper that did not match the flare - it was a limited run of race cars using off the shelf parts form different models, and fit dint matter much on race cars back then, I doubt that is what we are looking at in your pic though )

Unlike the bumper, here are pics of the MA shaw fenders fresh out of the box with no rework
(bumper needed a bit of love)

You might be able to find a pic on my build thread
Saving a 73 from the crusher...

[Nux]

Fiberglass is easy to work with, but very labour intensive. You can get a nice finish and good quality paint, if you prepare the fiberglass properly. It will take much more work than with steel. But it can be done.

My car has fiberglass fenders, hood, bumpers and doors. To get it from at very rough urban driver, to a nice painted finish took a lot of work.

[Bill Douglas]

The fit is one thing, but in regard to paint...

Use a high build primer then sand it to fill in the minor pits and imperfections. There is some stuff you can either put on with a sponge or spray on, that you sand until the black stuff is gone. It shows as black in the pits and imperfections. And keep using this until it's perfectly smooth. Then you clean it off with prepsol or similar degreaser. Then you paint it. there is no reason why the paint finish won't be as good as if it was on steel.

[tdskip]

Originally Posted by jpnovak

That is a bumper problem. Looks like it was not mounted/fit correctly. Also looks like NB bumper on flared fenders.

Oh geez, missed some responses here, Sorry guys, appreciate the input.

So not a fiberglass thing as much as a care/fit issue (so long as the fiberglass bits are quality).

Fair summary?

[tdskip]

Originally Posted by Nux

Fiberglass is easy to work with, but very labour intensive. You can get a nice finish and good quality paint, if you prepare the fiberglass properly. It will take much more work than with steel. But it can be done.

My car has fiberglass fenders, hood, bumpers and doors. To get it from at very rough urban driver, to a nice painted finish took a lot of work.

Great color!

[tdskip]

Originally Posted by wayner

I tried to find pictures of my front bumper under construction.
If I find them Ill post them but, essentially took cuts out of the bumper in some places, and used metal foil tape as backing to build new fiberglass on to fill the few inch gaps that were needed.

Next, once it was all one piece again, took curf cuts out of it in order to expand the profile of the end of the bumper to meet the flare exactly properly.

Again, created new fiberglass in between


(also, note that the factory SC-CR car had a bumper that did not match the flare - it was a limited run of race cars using off the shelf parts form different models, and fit dint matter much on race cars back then, I doubt that is what we are looking at in your pic though )

Unlike the bumper, here are pics of the MA shaw fenders fresh out of the box with no rework
(bumper needed a bit of love)

You might be able to find a pic on my build thread
Saving a 73 from the crusher...

Thanks - will study your thread. Great work Wayne.