Charles: Congratulations on your progress. With reasonable care the glue on gunwales will last a long time, witness my 1998 MCA cruiser that has seen extensive use with no gunwale damage despite a few dings (i.e. souvenirs) in the canoe itself at or below waterline that needed repair. I'm looking forward to your pictures.
Richard C. Berling
Madison WI 53714
I took advantage of having my son home from grad school and put him to work as we installed the inner gunwales. I would have been able to do it without him, but I would have had to do one at a time.
It was good to have him in the shop, he suggested we use cauls to cushion the gunwales from being dented by the C-clamps.
He also suggested that we wipe off the excess glue and got me thinking about how to do that: we used acid brushes around the scuppers and wiped the squeezeout on the underside of the gunwale using paper towels. Took us a while, but it was a really good idea to do that while the glue was still uncured.
I used epoxy thickened with colloidal silica. I actually ran out of that stuff when I glued the outer gunwales and opened an old container of "flox", which is chopped cotton fibers, basically cotton dust, which is used in the same manner as colloidal silica. And I had a bunch of it from my airplane building days.
Anyway, the big news is that I did not use any screws at all. Both inner and outer gunwales, as well as the decks, are bonded in place by epoxy resin thickened with the afore mentioned colloidal silica and/or flox. It went very well and has stiffened up the hull considerably. I was all set to use screws and just never got around to it while my son was in the shop and we were both working quickly to get them installed. As we clamped, it did not seem necessary to drill and install screws too as I had so many clamps I actually had some left over unused.
In addition, I installed both decks, which took a LOT of very careful sanding and planing so that they would fit without bowing out the gunwales. I must have spent half a day on each before I was satisfied with the fit. Gluing them in was almost anti climactic. I made them from laminations of purple heart and white ash.
Once all the clamps were removed, I asked my wife to heft one end of the canoe while I lifted the other so she could get an idea of how heavy it would be and her comment was that it seemed as heavy as the homebuilt fiberglass barge we were given. I don't think it is though.
Spent most of the time finish sanding the gunwales and applying an epoxy coating to the thwarts, which I removed from the canoe in order to do so. They also will get finish sanding before the varnish is applied to them.
I have lots of pictures to upload.
So lots to do yet, but it certainly looks like a Spring launch will be possible.