Back yard windows

The aft cabins on most mid-sized catamarans form the sides of the aft cockpit. A big advantage of these cabins in Oram catamarans is that the rear panel has a large hatch which faces the walk-through on each hull and therefore a view of the “back yard” of the boat.

These not only give quick access to the stern, they also are a first class hull ventilation exhaust and have on at least one boat provided an excellent view of a large crocodile coming aboard. A story for another day about how Oram sterns are so well designed for ease of boarding from a dinghy.

Below is a photo of Atti in his cabin opening its new window.

Below – This is how the cut outs were made without the need of a doubler, and the hatches pre-fitted to the cabin panels.
A template is made first, marked off the hatch, adjusted for the router’s guide offset then used to cut a trench.

Below – The trench filled with epoxy and a loop of rolled up unidirectional glass.

Below – The over filled trench sanded flush, so we have a very strong inner edge reinforcement on the cut out.

Below – The template is refitted exactly and a different offset guide used to cut another trench exactly outside the earlier.

Below – The outside trench is filled with silica and epoxy to ensure the hatch machine screws pass through solid material, not the balsa core.

Below – After curing, the over fill is again sanded flush.

Below – The cut out is then made carefully and simply with a jigsaw and the cut out “waste” just happens to be the almost perfect shape and size of two companion way steps, albeit still Siamese twins for a while.

Below – A light sand of the inside edge to take away any remaining balsa.

Below – The hatch is offered up and the screw holes marked under Jem’s careful supervision.

Below – The hinge offset mounted screw locations are counter-bored to the laminate and over-filled with silica/epoxy.

Below – After re-laminating this working face of the panel, all the mounting screw locations are drilled through.

Below The up close and personal view of screw locations in edge of the reinforced core.

Below – Now all I have to do is under bed storage, bed base, sides, deck and paint.