I made the usual preparations (planing, sanding, fitting) and epoxied one of the bottom front ply bracings. Since it is a long setting epoxy, I do not remove pressure (clamps in this case) before the next day. The 2. and 3 rd picture show the top plywood braces. Inner view shows the insides coated with the same epoxy used in glueing, only slightly thinned with ethyl alcohol. Again a very small amount is needed. I think I will use the same method throughout the construction. In my humble opinion, it is better than using something like spar varnish. If you have to pre-coat the part, you cannot use epoxy on top of any varnish. So you have to be very careful to leave glue joints unvarnished. In my case it doesn't matter because it is tha same material.