Fiberglass drilling

[One arm sailor]

Hi all
I have never drilled a hole in fiberglass! Is there any thing I Shaun know before I start? I'm installing a depth sounder and I need to drill a 2 inch hole for the cockpit display.
Thanks

 

[One arm sailor]

"Should" not Shaun (correction)

 

[repawn]

I am relatively new to this - but have drilled more than a few holes now - it isn't really all that different from drilling into wood. Take your time and you won't have any issues.

 

[jibes138]

It is easy to chip the gel coat around the hole. Cover the area with blue painters tape before you start. Run the hole saw backwards to get it started and through the gel coat. It will want to fracture the gelcoat when it breaks through. Use the pilot drill hole and drill from both sides so the slug breaks loose inside the hole. Hope this makes sense.

 

[topcat0399]

Use a vacuum while cutting - unlike saw dust, fiberglass dust is very messy and extremely itchy and annoying.

 

[Stu Jackson]

Start the cut with the drill going backwards.

 

[njlarry]

Ditto all the above. Afterwards sand or grind with a dremel tool a bevel around the edge. For smaller holes a countersink bit bevels the edge quickly.
Prevents stress cracks and gives a surface to seal around the fasteners.

 

[One arm sailor]

What an awesome community! Thanks to all.