Hard Dodger

Design

While we were unhappy with the performance of the fabric dodger, aesthetically it suited the boat. Therefore we decided to use the basic form of the fabric dodger in the solid dodger design.

The solid dodger is strong enough to stand on and support port and starboard handholds.

Unlike the fabric dodger, the aft handhold was fitted below the level of the top, so a sweeping boom could not remove our fingers!

The dodger has a zippered plastic front window to provide air circulation.

The solid dodger also allows the use of lights, storage pockets, binocular and instrument holders inside of the frame.

Construction

The hard dodger is a composite GRP structure. We used the fabric dodger’s tube frame to get the basic shape for the mould frames. The mould frames were cut out of MDF, an easily cut particle board.

Next we built a foundation that would both accurately locate these frames and would be strong enough to remain intact during the actual construction. With plenty of glue, fastenings, diagonal bracing, and tightly fitted joints, the formwork was stiff enough to proceed with the foam planking and glass fiber application.

Once the mould was completed, the foam base was formed to the shape of the cabin top and the mould was moved to the shed we built beside the boat.

The remaining parts of the formwork were fitted between the MDF mould frames and the foam base.

The next job was to build the formwork for the acrylic window moulds. This was a two step process. First solid timber was fitted to the dodger-mould in exactly the position the inside face of the acrylic would lie. Over this wood form another series of mould frames were fitted and when removed a sheet of thin galvanised steel attached to make the form the heated acrylic would be shaped upon. The acrylic sheets are evenly heated in a large oven and then laid in the mould until cool.

The PVC foam core for the top was laid in 100mm wide planks over the mould and temporarily fastened in place from the underside.

The glass layup started with a 750gsm triaxial cloth laid fore and aft and wet out with epoxy resin. Additional layers of 300gsm unidirectional “S”glass and 450gsm biaxial cloth made substantial beams over the window openings.

Simple wooden frames covered in packaging tape (as a release agent), were used as moulds to form the rabbets for the window openings since at the time we did not have vacuum-bagging equipment. The narrow window frames which take all the load, wind and waves, as well as Peter’s when standing on it, had to be substantial. These were laid up with both uni “S” glass and 450gsm biaxial cloth, again using epoxy resin (Peter only builds with epoxy). Once all the outside glassing was complete, an epoxy filling compound was used to fill the weave of the glass and provide a thick enough coating to sand to a fair shape. Using a thick filler a rough cradle was epoxied to the top, both to hold its shape and support it at a good working height while the inside glassing was done. Windows were to be fitted into a shallow rabbet on the inside of the dodger so the foam was rabbeted to 9mm deep and 35mm wide. This gives enough surface area to only need to glue them in, no fastenings required, with silicone sealant. The 3mm minimum thickness of sealant is to allow for expansion and contraction of the acrylic window material without causing the bond to fail. While a little more difficult to do, compared to simply screwing them on the outside, this method results in a cleaner look to the finished product.

Before glassing the interior the wiring for the lights was fitted into channels routed in the foam. Interior layup was 450gsm biaxial and, again, multiple layers of 300gsm “S” glass for the beams that carry the top loads. A filler coat was applied and then first the inside, and then the outside surfaces were sanded to a fair shape. Lastly, bezels made by using plastic takeout cups as moulds were glued and coved to the inside for the lights to be screwed to.

Before finally painting the dodger it needed to be checked for fit on the boat and a dry run made to check that the bolts moulded into the base did go through the old holes the original hand-holds had used.

With the assurance that the dodger would slide easily into place, it was taken to a car-paint shop in Marmaris. We had expected the painters to spray a high-build epoxy primer but instead they gave the entire dodger a thin coat of polyester putty. The dodger was, after many hours of finish sanding, sprayed with modified acrylic two part automotive paint.

Once the paint had cured for a few days we glued the dodger into place using 3M 5200. Knowing that at some point in the future someone was going to want to remove the dodger, small blocks of rubber were placed between the dodger and the cabin top so that a guaranteed 3mm minimum of sealant was assured. To cut the sealant, a piano wire could be used to slice it. In fact, we did end up cutting the sealant in this way when we decided to do the Great Lakes trip and then trucked the boat to Seattle!

Once the acrylic windows were bent to shape at the acrylic shop, they were glued into the rabbets with an industrial silicone designed to hold windows in high rise buildings.

The zippered forward window was secured in place with a bolt rope on the four sides. This window can be unzipped on three sides and folded up for air circulation and access to the mainsail traveller.