Fixing holes in fiberglass

[bentley]

I recently install a new hardtop in the boat, I removed the vhf antenna's and now theres exposed bolt holes, what's the best (easist) way to fix these.

 

[Peahead]

I would use Marine Tex or Interlux Watertite epoxy filler to fill holes....sand/fair in then paint or gelcoat to match boat colour.
If you wanted to do a really "quick and dirty job" , I suppose you could fill holes with 3M 5200 which would take 30 seconds but it would always be visible as filled holes.

http://www.brownspoint.com/store/pc...y-p70008.htm?gclid=CNj0tojwnswCFU9cfgodEgUCEg
http://www.westmarine.com/buy/interlux--watertite-epoxy-filler--P004_120_005_008

 

[gungadin]

There is quite a few gelcoat spiderweb cracks around the larger hole that need attention. I would use a small grinder with an 80grit flapper disc to cut through the gelcoat until just into the fiberglass itself, then fair the resultant edges out for at least a couple of inches all around. Clean up the edges inside the hole so that the fibreglass is clean. Attach a piece of shape conforming plastic, spray the plastic with a light coat tresemme of #5 hairspray, to the back side of the hole with duct tape, making sure it is up tight against the hole. Mix up a little West system epoxy and thicken it up with 410 fairing compound so it won't sag (peanut butter) and spread it evenly in the hole and into the area you faired, just under the height of the surrounding gelcoat. Let it set up overnight, then hand sand it with 120grit paper to remove any blush. Now use the Marine tex and put it on just proud of the surrounding gelcoat. Let it harden and wet sand it with up to 800 grit wet and dry. Blend polish it. Remove backing from the inside.

The little holes are done basically the same, but just fill the holes up with epoxy before sanding out the cracks and applying the marine tex. Just use duct tape on the back side of the holes to keep the epoxy from coming out.

 

[Wild Bill]

For the big holes why not just use poly resin and Matt to back it if you can access and fair with epoxy? Thinking you would have backing structure and strength and then could use epoxy and micro balloons for easy sanding. I too have holes to fill and the small blind screw holes I figured epoxy and microbaloons.

 

[searun]

Gungadin has the right approach. Its not that hard. Only trick is matching colour of gel coat.

 

[bentley]

Thanks guys, I grabbed some marine tex, I will try it this weekend