A Hatch From Scratch

Our article from the May/June 2009 issue of Good Old Boat

Sometimes a simple solution to a problem is not always simple. Although our former boat, Sea Trek is a great cruising vessel, there are a few things we wanted to change. One draw back was the lack of good ventilation below. With six opening ports we thought it would not be a problem. But with ten-inch high bulwarks around the deck it left something wanting. The only deck hatch is forward over the vee-berth. This is great for sleeping but still not great for airflow thru out the main cabin. We added strategically placed solar vents and cabin fans but in the tropical areas we usually cruise it was still not enough.



Our main salon is very open and airy. We knew a center hatch was the perfect solution. It should have been an easy project to accomplish. Not being an experienced woodworker I knew I needed to seek professional help. I am not sure why but we just couldn’t get a carpenter to even come to the boat to look at or estimate the job for us. Some were willing to give us an exorbitant estimate based on my measurements, sight unseen. Believe it or not we went back and forth with this for six years.

One day I met up with a friend that had recently relocated back to our area. I knew he was a very good woodworker and had all the tools and skills necessary. When I mentioned my attempts to get someone to build a hatch he immediately offered to help make it happen. I was delighted to finally get this project started. Sea Trek is a very traditional looking vessel. The off the shelf hatches available just would not do. It had to match the forward hatch as closely as possible. Since that hatch was teak, this one needed to be the same. It also needed to be strong enough to withstand heavy breaking seas and handle the weight of someone walking on it.

The actual hatch size was to be 24 inches by 24 inches. We found a single piece of teak at a local wood shop that was ¾” X 10” X 9’. Cost was just under $200.00 including having the shop do some of the finished planning for us. Since we wanted the hatch to open in both directions, two sets of hinges with removable pins were needed. We also needed to dog it down in both positions, so two sets of latches were needed. A good strong pair of hatch holders to allow us to hold it open in any position rounded out the hardware. Total cost for the hardware was about $95.00. The final piece would be the Lexan top for the finished cover. We chose the dark smoked to again match the forward hatch. It needed to be very strong so we decided on ½ inch. This was slightly thicker than the forward hatch, but in it’s center location it would get walked on quite a bit. Cost for the Lexan locally was $81.00.

Then the construction was to begin. There would be two finished pieces. The main hatch itself measured 24”X24” on the outside and needed to be only 3 ½ “ deep. This would give us a low profile on the deck and fit flush with the headliner inside the cabin. A strip frame was added to the area that would sit above the deck. This would position the hatch frame at the right depth on the inside and give us an overlap on the deck for thorough bedding. Deck leaks are always a concern for us. All pieces were screwed and epoxied together with the screws countersunk and bunged. Next we needed a 1 ½” finished frame for the underside that would attach to the very bottom of the hatch. This was to nicely finish off the bottom that was flush with the headliner.

The second piece is the hatch lid. It needed to overlap the main frame so that water could not work it’s way under it. We decided to allow the lid to sit on the strip frame we added that would rest on the deck. This gave a nice even appearance when the hatch was closed. Everything gave the same appearance as the existing forward hatch. The hatch frame stood 2 ½” above the deck. The lid was 3”tall. But when it was closed, the entire hatch only stands 3 ¾” off the deck because of the overlap. We flush mounted the pieces of Lexan to the top and used a polysulfide sealant to make the Lexan watertight. All fasteners on the Lexan were counter sunk for a nice finished look. Next we added five, ¾” wide strips across the lid. This was both decorative and functional. It hides some of the fasteners in the Lexan and keeps it from getting too scratched when we have to walk on it. We decided that all corners would be overlapped instead of being mitered. This would give us greater strength. Also the finished frame and top needed to be square.

The next and most important step was the placement. I had designed it so that it fit nicely between two teak crossbeams on the headliner. Using the frame itself as a template, we drew out the inside area with a pencil on the interior headliner. Before anything else, we checked to be sure the template we had just marked was truly square. Next we checked to be sure the interior finishing frame would fit clear of any obstructions. I believe I rechecked each of these about ten times. Once I was satisfied that this was the spot, I drilled a ¼” hole through the headliner and deck at each corner. Now I was committed. The main section was then taken on deck and lined up with the four holes I had drilled. Once I was again satisfied with the positioning I drew an outline again using the frame as a template. This time using the outside dimensions. Once again, everything was check to be sure it was square. Then it was checked again….and again….and again.

Now comes the scary part. I was about to cut a two foot square hole right in the middle of my deck. I can’t tell you how many times I asked myself if I had totally lost my mind. We needed to do this in the neatest fashion possible. The executive officer was already making threats if one ounce of fiberglass dust got into the cabin. By taping plastic trash bags to the headliner outside of the area we were working in, we just about eliminated that problem. The exec stood by underneath with a vacuum running just in case. I was concerned that we might have wires for the cabin lights in the area so the saw blade was set to just cut through the deck. It was do or die time. When I get myself to this point I go a little crazy. I ask myself over and over, did I miss something? Was one small calculation off? This is major surgery. Finally, we cut off the power inside the cabin just in case and fired up the trusty power saw. Even with a good carbide blade, Sea Trek was not giving up this section of her deck easily. Finally the cuts were finished on four sides. Because the power saw blade is curved, the cuts did not go all the way to the corners. I needed to finish off with my saber saw, also with a carbide blade. Once the section of the deck was removed the headliner was exposed and no wiring was present. In hindsight, I might have cut out the headliner first to make sure. With that, I adjusted the power saw blade and retraced my steps to cut through the headliner. I now had a perfectly square two-foot hole in my deck. I was sure we would have torrential rains beginning in about three minutes and lasting for days.

Another decision I made was to not use fasteners to attach the hatch to the deck. Because the deck works to some extent and I wanted the hatch to work with it I decided to use a liquid fastener we commonly know as 5200. After carefully taping off the deck and the frame around the hatch I applied generous amounts under the lip and were the frame went through the deck. I used the mahogany color since it was kind of close to the teak. Next I positioned the lid on top of the frame without adding the hardware yet. And finally a five gallon bucket of water added just enough weight to the whole thing as to seat the frame solidly in the 5200 but not squeeze it all out. Then the messy part, cleaning off the excess. And this is how she sat for a week. I wanted it to be undisturbed until the 5200 had completely cured.

One week later the finishing work began. Before the hardware was attached we did the required varnishing. The interior headliner frame was fitted and since we wanted a screen to keep out the bugs we worked on that. A simple wood frame was made that fit inside the opening. A ¾” strip was attached at one end, which ran the length of the inside. At the opposite end on the corners two small 1 ½” strips were attached that could be turned to allow the screen frame to get past them. One end of the frame sat on the strip on one side and the other end sits on the small pieces on the corners when they are turned inward. A quarter turn of those two small strips lets the screen drop right out. I added some molding just above the screen frame so it could not be pushed or blown out the open hatch. Finally all the hardware could be attached.

This has more than surpassed our expectations. The difference this hatch has made in comfort and appearance to the boat was well worth the effort and the wait. The interior is even brighter than before and the amount of air circulation we have now is enormous. We now find we have to chase every piece of paper we put down, all over the cabin. It is not a project I would enter into lightly. The design and planning must be well thought out. I thought ours out for six years. A mistake could be very costly. But for those willing to tackle it, the rewards are wonderful. Careful consideration of structural integrity of the hatch and the decks, once these modifications are done should be at the top of your list. Our total expenditures for materials was about $400.00. This does not count the sweat equity. The satisfaction of such a project cannot be calculated.