Installing a day hatch

Instructions to replace a deck handpump with a day hatch (or to install a day hatch in a boat without one)

First off, I did this on an older Pintail that has a flat aft deck. The newer boats (IIRC '95 and up) have curved aft decks which will make installing a day hatch difficult. It was actually pretty easy to do, albeit a bit time-consuming. It took me 3-4 hours on the first day and an hour or two on the second to do the hatch. Fabricating and installing a bulkhead will take another 3-4 hours. It requires the following parts and materials:

- 1, 7.5" VCP hatch and mounting ring (or equivalent)

- epoxy

- polyester resin (optional, for bulkhead)

- 'glass tape

- 'glass cloth (optional, for bulkhead)

- 'glass matt (optional, for bulkhead)

- 2, 12" x 24" (or larger) pieces of polyethylene drop cloth (optional, for bulkhead)

- disposable brushes (chip brushes)

- lacquer thinner or acetone

- Marine GOOP

- scraps of minicel foam

- masking tape (2", if you have it)

I purchased all the fiberglassing materials and the GOOP at Home Depot, and the hatch assembly from a local shop.

You'll also need a saw to cut the deck with and sanding supplies. A fine wood rasp comes in handy, too. Don't forget gloves, a respirator and safety glasses, plus containers and sticks to mix the epoxy/polyester resin.

The procedure is:

1) Remove the pump and plumbing, then wash the underside of the deck to remove any dirt or salt.. I plugged the fittings in the hull and bulkhead with minicel foam scraps and sealed them with Marine GOOP. This was easy and it's reversible, should you ever want to use the fittings.

2) Cover the general area of the deck where you want the hatch to go with masking tape.

3) Set the hatch mounting ring on the aft deck and figure out where you want it (it's pretty apparent where it fits best). Obviously, the pump holes need to be within the hatch opening. The flange on the hatch ring will probably overlap a couple of the deck fittings slightly. That's OK, as you will trim the flange to fit later. Once you are happy with the position, trace around the inside of the hole with a permanent marker.

4) Invert the hatch ring (top side down) and center it over the circle you drew. Trace around the outside of the ring with a marker. The inner edge of this circle is your cut line.

5) Cut the hole slightly undersize. You can use a saber saw if you have one, or whatever you have on hand that will work. You want to use a fine-toothed blade to avoid chipping the deck.

6) Once the hole is cut, try to insert the hatch rim from underneath (working through the aft hatch). It probably won't fit, which is fine. Mark the tight spots and remove a bit more material with a rasp, sandpaper wrapped around a jar or a sanding drum on a drill. Work slowly until the top of the ring will just fit through the hole.

7) Press the hatch ring up against the underside of the deck. Mark the areas where the flange hits any deck fittings.

8 ) Cut/file/sand away the areas of the flange that contact the fittings until you can push it up flush with the underside of the deck. You may need to enlarge the hole in the deck a bit more in order to get the flange flush with the underside. You want a snug fit, but it's not the end of the world if there's a bit of play between the ring and the deck.

9) Once you are satisfied with the fit, roughen the flange on both sides with 80-100 grit sandpaper, then do the same to the underside of the deck for 2" around the hole. Clean the flange and deck surfaces with lacquer thinner or acetone.

10) Invert the boat on sawhorses, so you can work underneath it.

11) Mix up some epoxy, then coat the underside of the deck and the mating side of the flange with it. Press the flange into place from inside the hull. You need to weight it while the epoxy cures. I just set the inverted hatch cover on the bottom of the flange and placed a plastic tub of water in it for weight.

12) Wipe off any epoxy that squeezes out on the outside. On the inside, just spread it out on the underside of the deck and leave it to cure. BTW, I thickened the epoxy with a bit of Cabosil. It's probably not absolutely necessary, but it's good insurance against it flowing out of the joint.

13) Once the epoxy has cured (overnight), it's time to glass the ring to the deck. cover the inside of the hatch ring hole with masking tape, so that any epoxy that drips won't stick to it. Cut the 'glass tape into 2" long strips and mix up another, larger, unthickened batch of epoxy.

14) Paint the underside of the deck and flange with epoxy, then lay the 'glass tape strips into it, overlapping them so you have a contiuous surface. Use the brush to push them down (especially around the deck fittings) and make sure they're fully saturated with epoxy. Add more to any dry areas. Once the 'glass is down smoothly, let it cure overnight.

15) Once it's cured, remove the tape from the flange hole and scrape/sand any rough areas in the 'glass tape. I also rounded the inside edge of the hatch ring, as it was rather sharp. The hatch is done!

Installing the second bulkhead

I'm assuming that you also want to install another bulkhead. I opted to make one by laminating four layers of 'glass cloth with a layer of matt in the center. You can do it with all cloth or all matt, if you prefer. You can use either the epoxy you have left or polyester resin, which is cheaper. You just need to make a panel larger than you need, then cut the bulkhead out of it. Here's how I did it:

1) Cut out pieces of 'glass cloth and/or matt. IIRC, 11" x 22" is plenty large enough, but I suggest you measure the inside of the boat and just make the panel an inch larger in both dimensions.

2) On a counter or a piece of flat wood lay down one of the poly sheets, then mix up your resin of choice.

3) Lay one layer of 'glass on the poly sheet, then wet it out with the resin. Lay the next layer and press it against the first, then add resin where necessary. Repeat until all layers are in place and wet out.

3) Cover the layup with the second piece of poly, making sure there are no large air bubbles underneath. Place a piece of plywood, glass or whatever whatever flat material you have handy over the layup, then place some weight on top of it. Allow it to cure. Expect some resin to squeeze out. Once cured the poly will peel off the laminate easily.

4) Make a cardboard template of the inside of your boat where you want the bulkhead to sit. This is a time consuming process, as you're likely to encounter deck fittings in the way, but take your time and get a good fit.

5) Trace the pattern on your bulkhead panel, then cut it out slightly oversize.

6) Carefully fit the bulkhead into the hull. Again, this is a very time consuming, but take your time. The bulkhead doesn't need to be a perfect fit, but you want it snug enough at a few points to stay in place on it's own while you 'glass it in. If it ends up loose, tape or hot glue it in place from the day hatch side.

7) Prep the inside of the boat as before, then install the bulkhead using epoxy and 'glass tape from the aft hatch side. You can probably do the job with four strips, one each for the deck, hull bottom and both corners. IIRC, I glassed the deck side first, let it cure, righted the boat, then 'glassed the hull and corners.

8 ) Clean up any rough spots and you're ready to hit the water!