Drilling into gelcoat/fibreglass

[Meneyin]

I need to drill a run of 12 mm holes for lighting on my fly steps. Clearly this has the opportunity of getting messy, and splintering. What is the learned view of best way to minimise damage (apart from not doing it at all).

[Roberta]

I would use the correct size Forstner bit. It will cut the cleanest hole.

Roberta

[Bill Edmundson]

Also, tape over the cut before the cut.

Bill

[TAB]

If the surface is flat ish you could also use a router with a collet and the correct sized hole. Or a 12 mm plunge bit on a plung router.