This is the drill bit I used to put the holes in the glass. Notice the edge.. much like something that would be used to take off a cast. This bit worked perfectly for fiberglass.
To test the effects of different bits, I bought some 1/8" fiberglass. I'd talked to a few people about how to best approach the glass and gelcoat for a perfect cut, and got a variety of responses. One shop (professionals, mind you) told me a spade bit would give me a nice clean cut. In this photo, the spade bit made the hole to the far right, and the middle is from the special fiberglass hold bit in the previous picture.
I laid down about two or three layers of masking tape, and used a compass to outline my circle. The bit didn't really skate on the tape, so it went through just fine.
Here's a view of the hole from below deck. I think at this point I had removed the masking tape that I laid on below the area where the hole would be drilled. The hole was drilled straight down from the top of the deck.
So I couldn't resist - I put in the YakPod to see how it would fit / look. The YakPod is a modified Scotty rod holder extension bar. I cut the top bracket off with a hacksaw, sanded it down flat, drilled a hole about 1.5" deep, tapped it out for 1/4", and mounted this standard camera ball joint on a 2" piece of 1/4" set screw.
Here I've drilled out the mounting holes for the bracket. This is after tape has been removed from above and below.
I put everything together. At this point I was thinking about brass screws, an idea I eventually ditched.
Remember that 1/8" glass? I used one of the plugs I drilled out to cap the bottom of the mount. I epoxied the center punch hole. This would all keep water from washing into my boat. The rubber removable seal built into the mount to cover it when not in use is probably more "water resistant" than "water proof".
Once on, I sanded down the epoxy I used to plug the center punch hole, and sanded the edges down to give a slight bevel.
I used 3M Marine Silicone Sealant to adhere the plug onto the mount. I used these grips to keep a steady pressure for bonding.
When you drill fiberglass, you expose the core again, so you should put a thin layer of epoxy on these exposed areas. This made my 1/4" bolt holes too narrow. I had to redrill the holes to take them up one size. Avoid this step if it all possible by drilling a little large the first time.
This is what happens when you've been working too long on a project - don't forget to use masking tape. Without it, your drill will make a mess of gelcoat as seen here.
With bigger holes, I had to fill them back in with epoxy, and redrill my holes at 1/4" back into the plugs. Again, go this way the first time around.
Here's a photo from under the deck of the mounted screws and flush mount plate.
I switched to bolts that resemble the rest of the hardware on my boat. Here it is - the final product!
Here's a photo of the mount, with the yakpod shaft bungeed in on the side.
