Help! Fiberglass repair advice needed!

[MaineShark]

I was backing the Shark out of the garage with the hood up, and I thought it would clear the door but it didn't, by about and inch. Well, it used to clear, but I forgot about the increase in height when I put the correct-sized tires on.

So, one of the rearward "points" is busted pretty bad, and the fiberglass in the area where the hinges attach is in pretty sorry shape, on both sides. I'm wondering if there is any way to repair this, or if I need a new hood.

Joe

 

[1BAD80]

Before you remove the hood to work on it,
drill and tap three 1/4" X 24 holes in a triangle on each hood bracket, that will be your NET LOCATOR when replacing the hood and you wont have to realign it.


Cut Away the Damage
Never try to save damaged fiberglass; always cut it out and replace it with new laminate. Check all the edges and enlarge the hole if you find any additional delamination.

Dewax
Before grinding, always wash the area around the hole thoroughly with a dewaxing solvent. If you fail to remove the wax first, grinding will drag it into the bottom of the scratches and weaken the bond.

Grind
Use a disk sander loaded with a 36-grit disk to grind a 12-to-1 bevel around the perimeter of the hole inside. Also grind an area of the inner surface a few inches beyond the bevel to accommodate a finishing layer of cloth.

Mask and Mold
Mask off the area around the exterior of the hole and tape heavy paper or plastic below the hole to prevent resin runs from adhering to the surface.

Fabric
Cut the first piece of fiberglass matt to fit the hole with a substantial overlap over the edge. Cut the next piece the size of the hole, and the succeeding pieces larger and larger to build the laminate up and out to fit the leveled edge. You may have to allow the first layers to set a little and stiffen before applying additional layers. Unless you have reason to follow a different schedule, begin with two layers of 1 1/2-ounce mat, then alternate mat and 6-ounce cloth.

Using Polyester
For an even stronger repair you can also use epoxy, but not if the surface of the repair will be gelcoat.

Catalyst
The catalyst for both polyester and vinylester resin is methyl ethyl ketone peroxide, or MEKP. Do not confuse MEKP with the common solvent MEK; they are not the same.

Gelcoat
Gelcoat is essentially pigmented polyester resin. Start the repair by spraying or brushing about 20 mils of color-matched gelcoat onto the waxed backer.

Finish
For a finished look, cut a rectangular piece of mat and one slightly larger of cloth and apply these over the patch, smoothing them with a squeegee. Seal this top layer with plastic or PVA to allow a full cure. Remove the backer from the exterior surface. Fill imperfections in the new gelcoat with gelcoat paste and allow it to cure fully. Clean the area around the patch, then sand-if necessary.

 

[MaineShark]

Thanks. Unfortunately, I already missed step one. The hood is no longer connected to the car. But I think I can make a jig to locate the holes, anyway. It should work for the passenger side, but the driver's side is pretty well crunched, so I'm not sure how accurate it will be. I'll have to take a closer look tomorrow - I'm taking a breather right now...

My big questions with the hinge repair are alignment and strength: if I increase the thickness of the rib that the hinge bolts to, the hood will sit high over the hinge, and if I don't make it thick, will it be strong enough? The only way I can think of reinforcing it would be to get a piece of aluminum maybe 18" long, and screw it into the rib in several places, then bolt the hinge to that. But that leads to the alignment problem, again...

The damage to the hinge areas is on the underside, so I won't have to worry about gelcoat and painting. There's a few marinas around here who do fiberglass work. I'm thinking I might ask them if they can do it, since I'd probably end up spending just as much buying supplies and making mistakes as I would just paying them.

When it comes to the rearward "point", that's a different issue. I'm thinking I may have to just grind that off and put up with it until I have the car repainted in a few years, since I can't imagine any way to repair that and make it look decent, without repainting the whole car. In other words, I'm imagining that "broken off" looks better than "incorrectly-matched touch-up paint on one area."

I'm going to post some photos later to show the location and extent of the damage...

Joe

 

[MaineShark]

Point, outside

 

[MaineShark]

Point, inside

 

[MaineShark]

Driver's side hinge, righthand side

 

[MaineShark]

Driver's side hinge, lefthand side

 

[MaineShark]

It's hard to show, but the damage to the hinge rib on the driver's side is pretty bad. I'm sure I could just pull the broken piece off, if I wanted to.

Joe

 

[1BAD80]

I would make a new metal piece and refiberglass it in. You can make it longer and slide it up further for strength. Boat shop is a good idea. See if they can use Die Plank Resin, it's used for repairing cracked steel stamping die's temp. It doe's work I tried it for a body patch and ended up grinding it with 80 grit on a belt sander, it's strong, and one of the best bond's I came across on.
A good fiberglass person can make it look good. I cherried in all of my car.
http://www.hemmings.com/carshow/getsinglephoto.cfm?current_album_id=4745&friend=yes

 

[MaineShark]

Man, I'm really annoyed at this. I don't mind being wrong on occasion, but I hate doing something stupid like this (especially since I was just rolling the car back to clean the floor, not doing anything critical).

And I can tell I'm annoyed and not thinking straight, because I should have thought of putting the reinforcement inside the rib. I'm not sure if they are open tomorrow, or I might have to wait until Monday, but I'm going to talk to some people and see what they will charge to do the repair. I guess there are some advantages to living on the coast, even if the tourists get annoying at times...

Joe