Cutting composite boat deck...

Every once in a while, I entertain the notion of adding a day hatch to my favorite boats. My fav river boat is kevlar with a gel coat, while my fav open water boat is carbon-Kevlar mix, with gel coat. How would one best proceed? Anyone with experience, good or bad?
Thanks,
T

You’ll get the cleanest cut by using a high-speed cutoff wheel on a Dremel or similar tool. Kevlar doesn’t like to be sawn or sanded and tends to fray if you do so. Carbide scrapers work well for shaping Kevlar and they’re not terribly expensive.

You could try a Rotozip tool or a trim router with a carbide bit. Circle cutter attachments are readily available for both types of tool which should produce a perfect circle on the first try. Keep in mind that cutting a curved deck complicates things a bit.

First of all, do you also plan to add another bulkhead? That might be a lot more complicated than just cutting a hole and bolting in a hatch unit. If you haven’t researched the available hatches, there are some very good ones–such as those used on NC Kayaks. They come in various sizes and should be very easy to install. I’m just guessing, but I think they are constructed of ABS plastic. The 6" size with the toggle lock should be perfect for a day hatch on the deck behind the cockpit. If you’re talking about a hatch in front of the cockpit–that might be a bit more trouble.

Anyway, I don’t see a manufacturers logo anywhere on the hatches on my NC, so if you’re interested, give NC Kayaks a call at 1-888-441-8582. You might also want to visit their website nckayaks.com where you can see the type of hatches I’m talking about. They probably could send you one, or direct you to the manufacturer.

Getting back to cutting the hole; I believe that using a roto zip cutter with a circular cutter attachment might be the best tool, but I would practice using it on something prior to actually attacking the boat. Here again, if you do call NC Kayaks, they could probably give you some useful pointers for making the cut.

The decks , both front and rear are not flat on most kayaks. You will probably have to build a flat / recessed area with a spot to drain water away from the hatch area. Cutting a hole is a very small part of adding a day hatch. Here is a picture of a day hatch I added to my wife’s kayak. I also added another
bulkhead.

https://www.youtube.com/watch?v=JUZrxt3fcSM jig saw