rexx78

The previous Bubba cut two 6x9 holes in the rear interior panel, which was really stupid since there is no way 6x9's will fit in there due to the gas tank. Now I am going to repair these holes with a fiberglass repair kit I bought. Any advice on how to repair these holes? I have never done any fiberglass repairs before. My garage is not heated, does fiberglass cure by heat or by a chemical reaction. It is currently -16 C and I only have a bullet heater. Thanks in advance.

NHvette

The fiberglass resin (polyester) and hardener goes through an exothermic
chemical reaction to cure - similar to bondo.

I would still be concerned with the temp as low as that. The directions on the
can of resin should give you a workable temp range. I would try to get it
warmed up in there as much as possible.

I hear you, though. I need to run the kerosene heater all day to get the
garage warm enough to work with chemicals and paint. It takes incredible
forethought to be ready to work.

Good Luck.. :seeya


[Modified by NHvette, 3:35 PM 1/13/2003]

rexx78

Those tools sure are cold when you first start out aren't they?

I guess I will just get it really toasty in there and bevel the edges of the repair area, cut the mat pieces to fit, wrap a piece of plywood (that originally covered the area) with saran wrap and use that for a backing, then just go at it.

After it is all done, maybe I will come in and roll around the bed before I shower. Maybe I will be able to call in sick tomorrow because of some unknown rash/itch I got while sleeping... :lolg:

74-Roadster

If you can provide a back to support the matt, grind the perimeter of the whole, install your support (wood, cardboard etc. covered with duct tape and wax) and lay up 3-4 layers of matt cut to fit.

Depending on your access or lack there of, you could also lay up 2 or layers of matt on a soilid surface. Smooth cardboard covered with duct tape and a layer of wax will work. Make two patch sections that you can cut to fit. Then you'll nee to grind around the perimeter of the hole 1"-2" with a bevel. You then need to secure the pieces in place and lay 2 more pieces of matt (cut to fit over the new piece and into the bevel you created) right over them. Depending of difficulty in securing the new pieces, you can always use a couple pieces of duct tape and only do 2 or 3 small strips of matt. Once the strips harden up then you can remove the tape and glass the whole area smooth.

If you haven't done fiberglass work before, make the repair section on a workbench. It will give you the practice you need before you try laying glass in the back of a Vette. Where gloves and use old/cheap paint brushes and coffee cans.

rexx78

Thanks for the reply 74 roadster.

The gas tank and interior are removed, so there is no problem with access. What do you mean by the wax? Is this so the fiberglass doesn't stick to the backing? If so, will saran wrap work, even wax paper? How long will this repair take to cure?

CF6873

Since you have the tank removed and have plenty of room to work under there, I would grind the taper on the under/outside. Then I would get some plywood pieces that are bigger than the holes. Cover them with wax paper and screw them in place. This will give you a nice smooth surface on the inside. Then lay up 3-4 layers of matte from the outside. I would overlap the existing panel by several inches on all sides so the new saturated matte will not slide off. You may need to support it with some cardboard until it cures. As far as cure time it depends on how much catylist you mix in and the temperature. If it is mixed wrong I have seen fiberglass resin that never cured. I have also had it cure in the cup before I got it applied. Good Luck, Craig

74-Roadster

Since you have so much access, I 2nd CF6873's recommendation. When you can't use any type of paper release etc., duct tape with a layer of wax works well. For the wood, you can also use a couple of pieces of masonite and wax the shiny surface. Since you'll be working upside down or vertical, protect your floor and wear old clothes. Be prepared to have trouble getting the wet matt to stay in place. Again, tape can be your friend. When you cut the matt, leave some tabs or ears and don't coat with any resin. You can tape the matt into place until it cures and then use a blade or dremel tool to trim off the uncured matt. Repeat for succesive layers.

Take your time and go slow, it's messy and it's very awkward stuff the first time you work with it.


[Modified by 74-Roadster, 8:44 PM 1/13/2003]

69schemers

An old trick that my fiberglass shop uses is to use an old piece of flimica (counter top) and lay up acouple of layers of fiberglass on it larger then the hole. When dry, pop it loose and trim to the required size for the hole. Then bold the pieces into place. This makes it easier then trying to fill a large vertical surface.

djunod

What 69schemers recommends (using waxed Formica) is about the best way to go. You also need to get the temperature up over 60 degrees... 70 would be even better.

Fiberglass is real easy to work with, as long as you have all the stuff you need. I get most of the stuff that I need from http://www.tapplastics.com/fiberglass/index.html. You don't have to pay hazardous material shipping charges. I use their parting wax and PVA mold release to make sure the fiberglass doesn't stick.

69schemers

djunod, what do you use, Vinylester, Polyester or Epoxies? I have heard pros and cons about each, but have not heard which would be best on a vette. Epoxies have a low shrink, but the Vinylesters perform better under heat.

djunod

Polyester resin is what is compatible with the fiberglass on a C3. I've bought gallon quantities from TAP. When making molds, I've used Polyester resin from Walmart. I think the only place to get spray GelCoat is Ecklers.

At some point I will experiment more with more exotic materials. Right now there is no reason for the extra expense involved. That TAP plastic site has great info on different resin's & matte. You can spend a lot of time reading there.

Rich80

Another thing to consider .. Is this fiberglass patch gonna smell to the high heavens being it will be in the interior. Ive done fiberglass work on boats and that stuff stinks even after its cured. Would paint cover the smell or would the smell eventually go away? :smash:

Big Fish

The smell will go away once the resin is cured, but if you have an attached garage you will for sure get the odor in the house. I've been doing this for 3 weeks now, and is my wife ever pissed. :mad

djunod

Yes. My wife hates the smell. My boys do to. I love the smell. I grew up messing around with resin though.

You won't have any smell in the car after the resin cures.