Fibreglass repairs

[jimmi]

I am looking at replacing winches on a fibreglass boat and it is going to involve drilling 5 new holes for the bolts in proximity to the holes for the old winches.
To reinstate the strength before the new holes are drilled I was wondering if it would be sufficient to fill the holes with resin or should fibreglass cloth be applied to the underside. The new winches will be taking a greater load than the old ones.
Any suggestions appreciated.

[Itchy&Scratchy]

To be safe you need to grind out the entire old hole/holes and rebuild the strength back layer by layer to at least the original layup strength, preferably stronger, before redrilling new mounting holes for the new winches.

Resin on its own has no strength at all , its only a binder for the matt/cloth.

If youve ever put your hand on a sheet, wound onto a winch in a big blow, youll know how much tension there is running back to the winch- imagine one of those ripping lose and hitting a crew member in the face. Theyll be dead before they hit the deck.
Sorry to be macabre, just trying to illustrate the importance of doing this job thoroughly.

Have fun
J

[PAR]

The use of a big ass backing plate can absorb and transmit the loads, better then hole filling. Metal backing plates are very effective as are plywood.

big ass backing plates rule

[TollyWally]

I love it when you guys use technical jargon!

Not 100% true but the old fishermans maxim "if it can't bend it can't break" is another favorite of mine.

[jimmi]

Thanks for the replys.