Building Logs

Deck hatches

Posted by Paul

Many months ago, when I glassed the strip planked hull to deck turn panel and even further back than that when I glassed on the D section top, I knew back then that I would eventually have to cut hatches into the various places for 2 important reasons. Firstly it is the only way to get back into the areas below the deck in order to glass the panel on from the inside. It is glued but not coved and glassed. The bow inside decks were coved and glassed on before the hull to deck turn panel went on but of course you cant glass the inside of the deck turn panel without access to the bulkheads from the inside.

Most of the bulkheads give you access inside the boat and for the area between bulkhead 0 and 1 I cut a hole into bulkhead zero, glassed the hull to deck through the hole, glued the piece in the cut hole back into the hole (I cut it with the jigsaw table on a slight angle so the sides sloped in so the piece cut out could not push through) and glassed over the front of bulkhead 0 before the nose cone foam was glued on. That only left the area between bulkhead 1 and 2 (between 2 and 3 were accessed from inside the boat) and from aft of bulkhead 3 back is inside the living space of the boat. And I put a false floor into the space under this proposed hatch so that it remained buoyancy below it for about 2/3’s of the volume and only the top 600mm or so is hatch space.

The plans tell you exactly where the bulkheads are so I didnt need to have them marked from the outside of the boat. Same with the D section mini bulkheads. So marking out the hatch positions was fairly simple. I settled on 400mm high and 600mm wide. The spacings between the D section sections is 800mm so 100mm either side of the hatch to the side walls worked well. Whilst the size of the D section is about 1000mm from the peak to the bulkhead aft, the catwalk kicks into the D section at about the half way point, so I again spaced the hatch at about 100mm forward of the bulkhead wall at the aft of each well and 400mm lids stopped them just short of the catwalk for the middle hatch and of course the hatches either side had to match it.


The openings are still big enough that I can climb into each well if need be. The middle well is the emergency anchor well and will hold surprisingly enough, the spare anchor with a mostly rope rode (you have to have at least 10 meters of chain to weigh down the anchor shaft otherwise it wont hold because of the angle the shaft will take if not weighted down by chain). The main anchor is directly behind the emergency anchor and will have an all chain rode and has the anchor winch inside the well. I will use the windless on the rope of the spare anchor to retrieve it and for this reason I will probably hinge this hatch lid from the forward edge, but the hatches either side (spare sails, spare halyards and sheets and spare mooring lines).

The hatches in each bow will have mooring lines and fenders. The bows of course are tapered. But for a hinged door to work, one edge needs to be square to the sides. So to keep the hatch lids roughly the same size all over I made these also 600mm along the square edge. Then the narrower forward edge I made 300mm and the wider aft edge I made 500mm and then drew a line from each corner to finish the dimensions of each side. I rounded the all the corners with the same radius curve, I am not sure of the size, but about the size of a soft drink can.


Will all the hatches marked I simply cut them out with a jigsaw. I started the cuts with an angle grinder with cutting disk on it along a straight edge then finished with the jigsaw to go around all the curved corners. All of these sections are curved decks. That means that the piece cut out of the deck becomes the hatch lid because it is already the exact correct shape. And of course it is made from the same stuff the rest of the boat is made from, in particular in these sections, duracore strip planking, which is balsa core with pine veneer each side that was cut into strips to create the curved decks, then glassed each side after the strips were glued to each other. During the cutting of the D section hatch lids I hit on a rich vein of glue which is much tougher to cut (and blunts jigsaw blades in seconds) than the balsa core of the rest of the hatches.

And of course having the balsa core means the edges of the opening and the hatch lids must be decored and back filled. As I have done with every opening in the boat I back filled with a uni rope around the opening than filled with filling compound. The combination of curved corners and uni rope ensures that cracks cannot form in the hulls or decks. My usual method of keeping uni in the trough is to make a strip of 3mm mdf with plastic to stop the resin sticking to it and forming a smooth edge and I secure it with elastic bands to screws I drill through the panel. But I cannot drill any holes in the deck now, I can have any points of possible ingress into the core. So I made the uni rope much thinner so it did not fill the trench much, and I used dress making pins through the uni into the balsa core to secure it until the filler went in over the top of it.


These hatches will all be wet hatches, that is, they will have drains in the bottom and store items that could or would go in wet such as fenders, rope or sails. And for this reason I am not bothering to have them properly seal. For a hatch to be water tight you need to build a watertight flange around the opening, which is usually a vertical flange that created a dam around the opening and in the case of a sloping deck hatch a place for the water that channels around the vertical hatch flange to drain. But I am not bothering with any of that. As nice as they are, I dont need them to be watertight. I have plenty of places on the boat for things that have to stay dry.

What I will do is glue and glass a ply pad under each hatch opening onto which the lid will sit and the pad stops the lid from falling through into the well and I will recess that ply pad slightly to allow for a rubber seal to go around the opening on the ply and this will keep water from pouring through but if water drips in, it will find its way out again via the drain and that is good enough for me. I will glass a thin layer of 200g glass from the front deck skin down the backfilled edge and a small cove around onto the ply pad. And I will glass the ply pad to the underside of the deck inside the wells. This ensures the ply pad is rock solid secure and protect the ply from moisture and the glass that runs from the deck to the pad ensures the backfilled hatch edges are completely sealed to protect the deck core from ever allowing moisture into it. The deck lids need to be able to be jumped up and down on and not give way at all. Not that anyone would ever jump up and down on a curved hatch lid but I want to know that no-one will ever fall through one of my hatch lids.


When all the lids are back in place (I have not yet decored and back filled the lid edges) I can set the hinges and latches and back fill the hinge holes. The method is to oversize drill each hole, back fill with filler then re-drill with correct size drill bit. Its a time consuming process but you cannot have any point anywhere on the boat where raw balsa core is exposed to the outside world because if you do, water will find a way to it and into the core which would eventually cause rot, which turns the balsa into mush, and you lose all structural integrity of the composite panel. Ironically, salt water does not rot timber only fresh water does. So its the trickles of rain you must guard against not the waves over the deck.


The pic on the left above shows the anchor well and the emergency or spare anchor well in front of it, with both hatch lids off. The row of 3 D section hatches would ideally all be hinged from above but I cannot hinge the emergency anchor lid from above because in the open position it covers the windless up down buttons and I would like to be able to use the capstan on the windless to raise the rope rode on the spare anchor. And the pic next to it shows why it will need to be hinged from below and open forward. The curved lid means you cannot hinge it along a side edge because as it opens the edges move away from the deck and a hinge cannot do that, it has to remain a constant distance in any position.

Whilst the hatch work was happening I finished the trimming of window and door frames. I stumbled upon a minor error in the kit when I came to create the main door frame and I had missed it up until this point despite having glued a panel into the doorway to narrow it to accommodate the pantry. I just had not been looking. My method for creating the glass frames is to de-core 50mm back from the edge of the door or window and I had already done that for all the windows including the 2 windows in the main aft cabin bulkhead, the doorway was the last opening to be done. I was about to use my usual method of de-coring these openings using the router with fence when I noticed that if I decored 50mm not only would the edge now be very close to the roof line but that it would be 50mm higher than the windows on either side. The windows and doors in this panel are part of the kit so apart from gluing the piece back in to narrow the door I have not altered any other aspect. So for some reason the designers decided that the top line of the door should be higher than the windows and not in a neat line. Many times it occurs to you that building a boat is a series of problem solving issues. The issue now became how to add 50mm along the top edge of the doorway into the doorway so that the top edge is in line with windows. I have no issue with the side or bottom edges just the top. I could either add a 50mm strip of duflex along the top and reshape the door before de-coring the all of that 50mm except the inside skin.

I decided against that when another idea presented itself. The doorway is a big opening and because it extends to within 100mm of the bridgedeck it needs to be well reinforced to withstand a wave crashing into the cockpit and not being able to stove the doors open, the flange that stops them must be very strong. I have some plates of 5mm solid glass that were offcuts from another boat build in the shed. I cut it up into 150mm wide strips and glued and glassed them to the inside edge of the doorway all around to form what would have been the inside skin similar to had I decored in 50mm from the edge, except this closed the doorway in 50mm all around. No big issue. I could then do my glass layer frame against the new inside skin created by the new 50mm frame around the doorway.



One the 5mm glass backing plate was glued onto the door frame I shaped it by using the router and the already shaped opening as the fence to make the 50mm plate (which mimicked the decored glass backing that would have been there if the opening matched the other windows and I de-cored in the usual manner) I could glass in the frame in the usual way, cove the edge and lay multiple layers of glass all the way around. I only laid 4 layers because of the 5mm solid glass backing all the way around. (I also only laid 4 layers of glass around the aft windows because they are high up and very unlikely to have waves hitting them directly so they dont need quite the strength of the rest of the window frames. Even with 4 layers of glass and no backing plate to thicken it out, the aft window frames are very strong. So the door frame become the thickest frame at around 7mm, the windows around the sides and front at 5mm and the aft window frames are about 3mm.


All of the window frames are trimmed and ready for the boat to be faired. The boat is painted before the windows are glued in and of course the frames would also be painted. So they will need to be bogged and faired. They are very smooth because of the peel ply but here and there are rough patches where the peel ply did not get fully adhered to the top layer of glass and in about 4 spots I had an air bubble under just the top layer of glass, all less than the size of a 5 cent piece, but the only solution to this is to grind that bubble layer out. There are 8 layers of glass so losing the top of a bubble here or there is of no concern but it will need to be filled over with bog and faired out.



The side windows are flat for about 80% of their surface area but curve in at the top forward corners. I am hoping that the small distance the window will need to be pulled in by, about 100mm will pull in with just a little effort and the tape and sealant will hold. Maybe it might just need just a little heat to make it pliable and it would set with the curve as it cooled again and was adhered in place.

I have mentioned a few times that building a boat this big is a series of problem solving exercises. I have thinking for a while how I was going to fit the shower arms. They have a thread on one end that is only about 20mm on the end of the post but the bulkheads they will go into are 20mm so the hole they go through has to be oversize so the entire arm goes through so that the thread is of any use. However, there is nothing to secure the post on the shower side of the bulkhead for the nut on that thread to tighten down onto so it was baffling me how I was going to get that to secure into the wall. The solution was to glue a female threaded whale fitting (the quick click plumbing system I am using) into a ply pad that would glue to the inside of the bulkhead the arms (there are 2 showers, one in the ensuite and one in the main shower side wall) will go through. Then the arm can go through the bulkhead and screw into the fixed whale fitting in the ply pad on the other side. Then the water hose clicks in one end and on the other end the opposite male thread whale fitting will go into the flick mixer out port. Into the flick mixer in ports, hot and cold go the same male thread fitting and click into the hot and cold water pipes. Too easy.


And just to finish the month out I started playing with some of the fun stuff that will be one of the last big tasks. Fitting new fangly stuff. Like radios, helm seats and steering wheel. I have a bunch of stuff I have been buying over the years and now I am in the final fit out stretch I have to fit some of it. It will go in temporarily, then need to be removed again to fair the boat, then be fitted and in the case of electronics wired up, in the final fix. Its fun fitting this kind of stuff.


Hopefully August will see the outboard wells fitted out, the rudders hung and the rear steps glassed in. I need the fairing to start in September so all of these tasks plus the pads on the deck for the deck hardware and the davits must be done before the fairing will start.

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