How do I cut and fit a hatch on a fiberglass Kayak?

I have a 12 ft Phoenix Slipper that my friend and I are reglassing, and I want to put a stow bulkhead and hatch in the stern. Any tips or suggestions?

ronmaggi7 years ago
If you have a hatch in mind, they usually come with a template or are easy to measure out. Bomar, Beckson and Tempress all make hatches that would work nicely. Lay out masking tape in the area that you are going to cut out. Mark your cutout lines on that. A hand held jig saw will make quick work of cutting out the hole, but you can use hand powered saws too. I reccomend against using a dremmel as they are hard to control on fiberglass. Wear a dust mask, goggles, and long protective clothing when you are cutting fiberglass as the small fibers are more than just irritating when they enter your lungs or eyes. Once your hole is cut, pull the masking tape and dry fit your hatch and mark the holes and outer lip of the hatch. You may want to drill pilot holes just deep enough for your screws. Mask off everywhere you don't want sealant. Use the blue painters masking tape to do so on the outside of the outer lip mark you just drew, and the outside edge of the hatch itself. 3M 4000 UV is an excellent sealant for this purpose. DO NOT use 3M 5200 as you will want to be able to replace the hatch in the future. Butter the raw edge of the fiberglass with your sealant. Then apply copious amounts of sealant to the underside of your hatch lip. Fit your hatch into place, and fasten just tight enough for sealant to squeeze out of all sides, but not so tight that all of the sealant squeezes out. Let it set up for a few hours so it can form a gasket. Then finish tightening up your fasteners. Once the sealant has cured, trace around your hatch with a razor blade and pull up the masking tape. You should only see a thin line of sealant under the hatch's lip.
gmoon8 years ago
Use a commercial hatch--there are several types. Screw-on circular, rectangular, etc. Some have insert bags, so you don't need to add the bulkhead. If you do want a bulkhead, cut and fit one from sheet foam. The foam can also add a little "worst-case" flotation to the 'yak. Be careful you match the resin with the type of foam, though. For instance, polyester resin will eat through some foam (polystyrene), but the better epoxy resins won't.