Drill hole or saw hole

Arronh

Petty Officer 3rd Class
Joined
May 31, 2019
Messages
88
Hi. I’ve been reading a lot and watching a lot of videos on fiberglass repair, because I might be doing some. I’ve never done it before, so I’m gonna practice on an old boat that I had no intention of ever using. There are some clean drill holes in the practice boat. Would I need to sand those down so that the hole is more tapered down, or could I just go straight ever a hole like that? If I need to taper it down, how far should I go.

Same me question for a circular saw cut. Go straight over, or taper it down?

thanks
 

emoney

Commander
Joined
Jul 19, 2010
Messages
2,551
Well, that's kind of a loaded question. It really depends on what you're hoping for in the finished result. You can absolutely "repair a hole" by sealing and covering it. That doesn't, however, mean you won't always see it and have your eyes drawn to it. I was watching the Crab Fishing Show on TV and they had to weld a patch on the hull to stop water from getting in. Looked like crap when they were done, BUT, no more water intrusion.

Now, if you're after a nice looking finished project, then you're better off to grind everything down to a taper so your repair won't be noticeable after the color coats are one. You can simply angle your circular saw blade to help that process along when removing large sections of say the decking.
 

Grub54891

Vice Admiral
Joined
Jun 17, 2012
Messages
5,911
For the most strength, you always taper both sides and lay in the glass, starting with the largest piece and progressively smaller diameter peices till the hole is close to filled. How far to grind? Till all broken glass id gone. Then a couple inches to create the taper.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,499
I filled in many 1-1/4 holes when I restored my boat. Feather the edges back an inch and build up in layers

I also fixes some O-carp holes.

If you are practicing, take a holesaw, and make some holes

And then take an axe and a pick-axe and make some holes

Then fix them so they are no longer visible
 
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