2016.09.27 - Well, Here Goes...
The task today was to cut the holes in the cabin sides, all twelve of them, to leave the side ready for trimming and installation. Having decided that today was the day I carefully measured everything again to confirm in my own mind that everything was as it should be, clamped the two sides together and made a start.
I drilled holes where the centres of the port lights were going to be and then cut out the round holes starting with the centre hole for no other reason than it has the bronze port light in it and so the diameter is a little more critical that the other holes which will be covered over with perspex.
The router and jig ready to go. I glued a small piece of plywood under the router end of the jig so that the bit was vertical. Ignore the pencilled circle, that's in the wrong place.
A few minutes of careful cutting later and I had my first holes. Notice that I'm cutting through both sides at once, taking of 1-2mm each time. this hole came out well but was just too tight for the port light and I had to use a round file to widen the hole a bit. I'll probably need to take off a bit more later since I'll be coating the inside edge of the hole with epoxy to prevent water ingress and that will make the hole a fraction smaller. The jig was set for a hole diameter of 178mm and it came out at 178mm and perhaps it should have been 179mm instead. But not a real problem.
Then it was adjust the jig for the smaller holes at 150mm diameter and cut those out.
Here we are with all six port light holes cut.
The port light itself is a tight fit but it does fit.
The outer ring will be screwed in position and this is what it will look like form the outside, more or less.
I moved on to the access holes for the open faced lockers next. Large holes were drilled in the four "corners" of the pencilled hole or where the corners of the rectangle would be if it were not rounded at the ends. These allowed me to use a jog saw to roughly out out the shape of the hole. The straight edges were within 1mm but the rounded ends were between 5 and 12mm as going around tight curves like this causes the blade to slant outwards and if you are not careful you get a wider hole on the underside.
Once the rough holed were completed I clamped the jig I made a week or two ago to the plywood and trimmed the hole using a follow bit.
Here one of the holes has been trimmed, the other two are in the rough state. You can just see the remains of the four holes drilled to allow access for the jigsaw blade in the rough holes.
And here are all the holes cut in both sides.
A closer look showing how regular the holes are by virtue of using the jigs.
There are one or two imperfections, the top veneer of plywood splintered away from one of the centre holes, but making that the inside will allow the bronze port light to cover over these dents and they will not be seen.
A very good three hours work today and no major mistakes.