Patching Holes in Avanti Body

[herbpcpa]

The door of my Avanti has two holes in it where a previous owner had mounted a rear-view mirror. The holes are kinda large because they used dry-wall inserts to screw the fasteners into the door.
Can I use a tube of fiberglass patch from a local boat retailer to fill the holes or would it be better to pay a body shop to fill the holes?

[sweetolbob]

Depends on if you want to use those holes again. I just did that on my 74 and I used fiberglass mat behind the holes and glass filled polyester resin to fill the holes but you will need to pull the inside door panel to do what I did. You can buy a Bondo brand kit at most auto stores with resin, catalyst and mat in one package.

If you are just filling and don't want to pull the door panel, I'd use the same kit to make a strip of fiberglass several layers thick and thin enough to fit through the holes. Masking tape the out side of the door to protect the paint, taper the holes on the outside and drill a hole in the strip big enough to put a small zip tie through. Use a piece of bent flat stock to go through the hole and butter the inside of the door with resin. Coat the strip with resin, shove it through the hole and pull it against the door with the zip tie. Hold until set, cut the zip tie off and fill the hole with polyester resin filler and smooth. If you want to use the same area for holes again, use fiber filled polyester to fill the holes after bonding the strips.

You could just take a chance on filled body filler to fill the hole but if you don't have any way to broaden the back side, you're asking for trouble down the road. The body shop will probably do it right by pulling the door panel but that's a large expense for something as easy as using fiberglass mat and resin.

Because the resin is catalyzed, be quick about what you do, particularly on hot days.

I'm getting pretty good repairing Avanti bodies after the last year or so.

Bob

[Halibrand1]

I am working on a 64 that's drivers door had decent sized remote mirror holes . I beveled the holes put tape loosely on the inside for a temporary backing and used Duraglass . It's a product that works similar to Bondo . I have used on fiberglass and steel with long lasting positive results . I am sure you will lots of helpful ideas here . Ed

[Mike Van Veghten]

What they said.

1. Taper both side of the hole, leaving a feather edge in the center of the material. The taper should extend about 4x the original hole size in diameter, both sides of the panel (inside the door and outside the door).
2. Cut 2 or 3 pieces of fiberglass mat (depending on the glas weight/thickness) to fill the hole, with a smaller diameter piece to larger diameter piece, layering the mat, do this on both sides of the door skin.
3. Soak the pieces of mat in resin, wet both sides of the hole in the door.
4. Let the resin get a little sticky, so it doesn't run out of position.
5. Put all of the matting in place, both inside and outside. Verify matting stays in place as the resin sets.
6. Let the resin set to "full" hardness.
7. Carefully sand as required to make sure the matting is below the door skin level.
8. Seal the sanded resin with a fresh coat of resin to seal and fully cover all of the matting.
9. Use resin or plastic to complete the final fill to original door skin level.
10. Prime and repaint.

No real need to "finish" the inner surface unless you want a better final outcome..!
And...wear gloves..!

Mike