Drilling Holes in Gelcoat

[SV-Viento]

Need to drill a couple larger 1 1/8" holes in gelcoat over RFP (no core just solid glass) regardless I have historically struggled to drill clean holes through gelcoat (of any size) without splintering/chipping the edges of the gelcoat surrounding the hole.

Any thoughts or advice on tools, bits, technique, etc.- Thanks!!!!

[Cheechako]

For that size I would use a hole saw. If you have to sand up to 1-1/8" from a smaller hole saw, use a 1" diameter drum sander in a drill that will avoid chipping even more. If you have the right size hole saw tape it off with masking tape to avoid chipping.
Any drilling over maybe 1/4" without chipping is better done by putting masking tape where you intend to drill.

[tsell]

Gel coat is very soft, if you start the hole with the drill in reverse you will minimize chipping and tear out. You don’t need much, I try to get about 1/8 “. Then you can drill the rest of the hole without worry.

[SV-Viento]

Originally Posted by tsell

Gel coat is very soft, if you start the hole with the drill in reverse you will minimize chipping and tear out. You don’t need much, I try to get about 1/8 “. Then you can drill the rest of the hole without worry.

Just learned so much from your reply starting with the use of "tear out". the rest of your advice also makes perfect sense as does the earlier post suggesting tape and sanding.

To be clear I abhor drilling holes in my boat but if I must I want them better than my past attempts - thanks.

[SV-Viento]

Originally Posted by Cheechako

For that size I would use a hole saw. If you have to sand up to 1-1/8" from a smaller hole saw, use a 1" diameter drum sander in a drill that will avoid chipping even more. If you have the right size hole saw tape it off with masking tape to avoid chipping.
Any drilling over maybe 1/4" without chipping is better done by putting masking tape where you intend to drill.

I have a nice dremel tool with sanding head as suggested - thanks!