Tony-B...
Posted: Wed Jul 30, 2008 10:11am
Post Subject:
porthole conversion
Yes it is perfectly feasible but it may involve stripping the inner cabin lining unless you are 100% sure you know where the cables run. Even if there are no cables or services running through the area to be taken up by the window there is still a question of how thick the cabin side, insulation and lining is compared with the length of metal cutting jigsaw blade available.
Often you will find the porthole retaining screws are also used to secure the internal wooden framing so any work involving the removal of windows or portholes may result in the lining becoming loose.
The method, assuming you will cut the cabin side & lining all in one, is as follows. Obtain a template for the window cutout from the supplier and mark out on cabin side. Drill a hole INSIDE the line to allow you to insert a jigsaw. With a metal cutting blade, slow speed and possibly dripping oil onto the blade cut around the outline. Smooth the cut edges, degrease very well and treat with rust inhibiting primer and several coats of paint. Offer up the window and mark the position of the screw holes. Drill and countersink BETWEEN the screw hole marks to accept battening to secure the cabin lining and also to provide a suitable finish on the exposed faces (unless a liner is to be used). Prime and paint the screw holes. Fit the battening. Drill and tap the holes for the securing screws, again painting to minimise rusting. Using either suitable "mastic" type sealer or sealing tape fit window into the hole you have cut. Ideally use stainless steel screws with a plastic washer under the head to prevent galvanic action between the frame and screw. I would also put sealer on each screw. Make good the inside. Tony Brooks
