I have 2 screws that tore out of my fiberglass. What can I fill the holes with and then just re-tap them with new screws?

You got a couple screws loose, eh? You could try "Marine Tex". I hear it works pretty good for stuff like that.

I figure I can just squirt it in hole let it dry then just screw the screw back in

If the back is accessible you can make a backing plate out of aluminum and through bolt with a nylock nut.

marine tex is like steel when it sets up

any kind of repair putty will come off as a whole when you put load on the screw as the fibers in the laminate will be cracked around the defect and the laminate will be mechnically compromised in that area.
grind off a little material around the hole and give it a beveled margin, the make a putty of epoxy and chopped fibers and apply a patch of light weave glass. this will not look very good, though. you can just fill the hole to make for a cosmetic repair.

in any case if you want the screw back in exactly that location, the backing up with aluminum and then using a self tapping screw or a through bolt with a nut behind the plate is the only way to go, everything else will not hold.

peter
austria

Here's a trick I've seen done and it works:

1. Mix some fiberglass resin.
2. Dip toothpicks into the resin and insert into hole.
3. Stuff as many as possible in there.
4. Let set up and cut or break them flush with the surface.
5. Screw the screw back in.

That boat was around for a year before it got traded and it never did loosen up.

Bruce

The 'West Epoxy System" manuals address this particular situation in detail. You can go to them directly on line or check with a distributor like BOAT US or WEST MARINE. It's great reference material to have in your home workshop. --- jp

I do the same a Turtle but I use five min. epoxy stuffs just about hard by the time you can pick up the screws.Spray a little wd40 or pam on the screws will help in takeing it apart to.

Ive got a little rule I stick to that says "If the sheet metal screw comes loose, do whatever you have to do to replace it with a threaded screw and nut" Not always so easy but Ive never had to tighten a screw twice. Ive made up aluminum or stainless plates with drilled and tapped holes, roughed up the surface and epoxied them in place as I tightened them up. Some blue locktite on the threads and your done.

Personally, If I were the boat god, Id make sheet metal screws illegal on boats.