Drilling Holes in Fiberglass??
 

I'm in the process of mounting my Pitot Tube on my transome (I'm a little hesitent to drill holes) where's the best place to mount & what's the procedure for drilling the hole?? fill with silicone or epoxy???

Put a piece of masking tape over the area to be drilled to keep the gelcoat from cracking around the drilled hole as you drill. Mount the tube per the manufacturer's instructions if you have them. Six inches to either side of the keel centerline but not in the area directly in front of a drive as a start. Put some epoxy down in the hole and let it partially cure to seal the transom coring(probably plywood). Use 3M 4200 urethane adhesive on the outer threads of the mounting screws(last 3/8" under the head)and on the underside of the plate that you are mounting. Some will say that this is overkill, but you will get no water intrusion into the plywood core if you do it right. NEVER use silicone on a boat, unless it is on an interior surface that has no connection to any underwater fitting and never below the waterline, but better still NEVER use silicone sealant on a boat. There are better sealants such as the urethanes.

Try to drill the hole above the water line.

I found that if you run the drill in reverse, its does not chip the gel coat

Is it to late to get a GPS Speedo? I would rather do that than drill a hole.

Take a screwdriver and hit the head with a hammer until there is a large enough hole. If that does not work do what Ren3 said.:D I beg to differ on the silicone idea. In the case of a flat chested woman, silicone is a must.:D On all boats.:cool:

Mitch, I do grant you an exemption on the most pertinent point that you pointed out (pun intended) about the one permitted/preferred use of silicone on a boat. Bob.

If ya center punch it hard enough, you won't even have to drill it..........:p

Good point. Get a GPS speedo, at least they work.

Drill the hole above the waterline
and use a cable cover from Bluewater
there about 3in long and you can put
4300 inside and they come with 4
screws.
We use them on thru hull Morse cables also never had a leak.
Black molded abs
Check www.bluewater1.com
or call Bill at 760-721-1951
Mike J.