Help me decide how to drill this hole...

I am replacing my rear Sony transom remote with the newer style remote. Problem is, the new remote requires a much bigger hole in the transom. I am worried that if I just try to use a big 3" hole saw that it will not remain centered over the new hole, as it needs to. Also, I am worried that if I try to use a jigsaw or rotary saw to cut out the diameter of the hole, it will be ragged and chipped. Any ideas?

(Message edited by atropine on March 07, 2007)

Cutout tool. Like they use for drywall. Thats what I used for all the thru hull fittings for my ballast system, and the hole for the paddlewheel for Perfect Pass. It spins a 1/4 inch bit at high speed and cuts nice and clean without cracking gel coat and is easy to control.

(Message edited by wake upppp on March 07, 2007)

You might be able to glue or clamp a piece of wood to the back/inside for the hole saw to drill into. Make sure you have the drill on reverse so you don't chip the gel coat.

When I was in need of drilling any of my finished fiberglass surfaces in my boat I used a Dremel with standard sawz all bit. It worked great! For extra insurance, place a piece of tape over the area to be drilled to ensure there isn't any chipping. I didn't have any problems and I didn't use any tape.

Similar to what Walt said, using the hole saw drill into a section of dowl rod that's a little smaller than the center hole in your fiberglass then use the dowl rod as a guide.

Or...you could wrap duct tape to your hole saw center bit to get it close!

Yeah, blue tape over the hole and a dremmel or rotozip type of tool. If you can scribe it somehow, there will be less chance of any chipping

Don't forget to get liquored up before you start drilling.

These pneumatic reciprocating saws work really well:


-Steve

Put a holesaw the same size as the small hole on the threads left over after you stick the big one on the arbor. Then go slow. The smaller one will stick out just far enough to keep the whole setup centered. Also a rotary with the blue rotozip bits work well. Or the airsaw like steve poasted.

Sam.... I just installed a Clarion remote in my boat about three weeks ago.... I can't say enough about the RotoZip! I was a little skeptical and concerned about the gelcoat as well, but I went for it and it came out very clean! Just mask off the area first with masking tape.... Drill a small pilot hole just inside the circle you plan to remove and proceed SLOWLY! Just remember, Measure twice, cut once! If I had pics I would post them, but it was pretty simple so I didn't take any! Another tip... I actually cut a hole out of a piece of poster board first to make sure my measurements were accurate with the size of the remote! Then I used the opening in the poster board to draw my cut-out on the masking tape... Use a new blade as well.... Good luck!

Steve has the right Idea.

Thanks everyone! Great ideas.

sam
If you use a jig saw or pneumatic saw get Remgrit blades or very fine tooth sawblades.
The Remgrit blades have abrasive material on the whole cutting edge and will give you a nice finished cut. They also are great for cutting tough stuff like Carbon or kevlar that can dull other blades quickly.

draw the hole then with the hole saw go backwards thats the best way