Best way to cut hull for exhaust tips

[Thunderbutt]

future boater:
Froggystyle:
I like the idea of a template and using it for a guide. What I do on retrofits is draw the circle, and cut the fiberglass with a pneumatic recip saw I have with a metal blade. Cooks though it like a samurai sword. Very clean too.
what about a hole saw? and should you tape both sides of what your cutting to avoid splitting as with wood? The hole saw will be hard to hold on a existing hole. Use the sawsall. The metal blade (fine teeth) will keep the glass and wood from splintering.

[Schiada76]

Don't use a sawzall! It'll wander and you won't get a perfect hole. Cut the plywood plugs with a jigsaw and the holesaw works great, or use the template/router method. The holesaw I used didn't spall anything on the inside at all either. You want a nice tight fit in the transom.

[Hotcrusader76]

BradP:
Don't use a sawzall! It'll wander and you won't get a perfect hole. Cut the plywood plugs with a jigsaw and the holesaw works great, or use the template/router method. The holesaw I used didn't spall anything on the inside at all either. You want a nice tight fit in the transom. Brad....I should have some pics for you tomorrow afternoon. Stay tuned...
~Ty

[future boater]

so the main thing is to use something with fine teeth to eliminate the splintering. i guess what has the fine teeth is all in how much you trust yourself.

[Jordy]

Damn, I guess I can't suggest using a dull chainsaw. You did say it was your friends boat right?

[Thunderbutt]

Make sure you tell us how it turned out and what you used. Why don't you call a boat builder and tell them what you want to do. Let us know

[BOBALOO]

heres what i did . screw a piece of wood inside the transom over the holes,it doesnt have to be round,then use a regular hole saw.looked bitchen w/new 4" rex stainless tips until they got that nasty white buildup on them.i hate to polish,almost should have left the orig bells on.good luck

[Rexone]

Mount anything inside the hole or across it (inside) for a guide for the pilot drill and use a 4" holesaw. Tape the transom first so it doesn't chip the gel coat. BradP's idea looks like what I'd use. Router will work too but maybe more work. I would use RTJas method as only a last resort before listing in the boat trader.