[DV8]

Does anybody have any advice on repair hairline cracks in gelcoat?? I have a "new" hood for my Pontiac, it's been sitting around awhileand has some damage. There are little hairline cracks in several areas on the hood. IS there a prefered method of repair?? Thanks for any input. I've look up fiberglass repair and have figured out how to fix a weak corner & edge. I can post photos if anybody wants a peek.

MIke

[427v8]

If it is truely a hood made like an old boat and does have gelcoat, I'd imagine you would need to use gelcoat to patch the gelcoat. sand out the crack and fill it with gelcoat or something compatible

Cracks in fiberglass need to be ground out and reglassed.
Otherwise they will be there forever.

Keith

[30modela]

If you go to a marine repair supplier, you can get a kit with instructions on the proper repair methods. If the hood has been sitting around for a while, check the bottom surface for any damage that could have caused the cracks.
Some reinforcement may be needed.

[DV8]

Right now hood is in a raw state meaning it needs to be painted the color of the car. I've heard i need to dremel out a v in the cracks at least make it big enough to fill with filler. these cracks are hairline and I know it would show up through paint. By the way it is an aftermarket "Ram Air" hood for a 93 Trans Am.

[427v8]

Yep, Rule of thumb is twice as wide as deep. wider is better

keith

[30modela]

My concern is the actual location of the cracks. If they are ob the side of or at the part of the hood where the scoop flows into the hood, filling the cracks will only be a temporary fix. If this is the location, "V" out the cracks and fill them in, but you will also need to reinforce the bottom of the hood with a layer of fiberglass. I would recommend using fiberglass mat instead of cloth. This is not a difficult repair to make, but you only want to do it once.

[fordSR]

Cracks in the gelcoat most likely means cracks all the way through to the underside. Fiberglass fenders are prone to rocks thrown from the tires causing similar cracks. Permanent repairs usually require grinding an area larger than the longest crack from the top side until just a thin layer of glass is left. Feather the edges around the grind area and lay in layers of non-directional glass and resin, rolling out the resin as you go until the area is built back up. Smooth the repair area with 80 grit DA sander, apply body filler over the repaired area and beyond and feather the edges. Apply epoxy primer, good to go. A dremel tool notch filled with body filler will show after the hood is painted, probably after it's been in the sun for a few days. Body filler must have a feathered edge because of the different expansion and contraction of the substrate and filler. If your hood has many cracks you might consider re-glassing the whole hood.

[Ripped]

I have a couple of fiberglass scoops from other manufacturers. These both had cracks in the gel. When I removed the gel, there were actually air pockets and voids between the glass and gel.

Unfortunately this is common in low budget layups, where they don't take the time to get the mat right down into tight corners.

Some manufacturers cut their resin with styrene (aka watering down latex paint) which reduces the strength of the polyester resin, but saves them money.

[Timmijoe]

I had starburst cracks in my hood...after sanding it, I found about a dozen air little pocket bubbles...i sanded them out then fiberglassed the divet, done deal...but you got to get the air out!!