REPLACING THE WINDOWS: THE CURSE OF 3M 5200 (2)
I never quite liked the appearance of the original big box windows
because to me they made the cabin trunk look too high for the hull. My decision was further influenced by the fact that
the company who supplied the back four ports did not have a portlight of that style that would come anywhere near filling
the height of the openings – or even matching the height of the back four ports. So I started thinking, why not
put even lower profile portlights in the front to hopefully provide a lower, longer look? I ordered four 12”x5”
ports, which were narrower than the rear 26”x 7” ports. What the heck, I was committed to do some fiberglassing
When I had both sizes of portlights in hand I made simple patterns to lay the fiberglass around to form
the correct size openings. A piece of ¾-inch pine was cut to roughly match the size and downward angle of the part
of the port that was to stick through the opening, the rain hoods. I allowed for a little wiggle room in the openings
so I could line up the ports when the time came to put them in. The wood was screwed to a piece of ¾-inch pine
that was larger than the opening in both length and width. It was positioned and screwed to the teak veneer and fiberglass
inside the cabin. This covered the opening and provided the backing to lay the fiberglass up against. All outward-facing
surfaces of the patterns were covered with mold release wax.
The sides of the cabin are curved and pretty much parallel to the curvature of the hull. The portlights, however,
are straight, so there would be gaps between them and the cabin wall. The pattern backboards were flat also. I
packed just enough Mortite (rope caulk) in the gaps to contain the fiberglass as I laid it up and prevent resin from dripping
into the cabin. The trick was to be sure to position the Mortite so that the new fiberglass would fill in to slightly
inside the dimensions of the portlight frames. This is so that none of the new glass will be visible beyond the frame
edges when viewed from inside the cabin. I was not entirely successful at this and had to do some trimming afterward.
(See Bad Work Habits and Stupidity for details)
Before I put the patterns in place I ground the outside edges of the
openings at an angle so that I wouldn’t be butting the new fiberglass up against the old. It also allowed for the glass
to grip more onto the old surface. Fiberglass, I’m told, has good strength in sheer but not so much in tension.
Applying the fiberglass was tedious but fairly straightforward. I had lots of cloth and mat strips of varying lengths
and widths already cut and handy. I wet the pattern backboard with resin and made sure to wet the glass strips to saturation.
It was not necessary to be fancy or exact. This was not a structural fix and there will be a time for sanding, filling
and fairing later. I worked in small sections since polyester resin “kicks” in just a few minutes.
Once done, the fiberglass looked pretty lumpy and uneven. I have some fiberglassing experience, but not a lot,
and one could see that this job was not professional grade. But body filler and sanding brought the new surfaces to
nice and smooth.