Logistics and boat building

 My dynel adventure is over, at least until decking time.  Two coats of epoxy, lightly sanded between coats, and the bottom is ready for paint.  I am fairly pleased with the result, but then again, I began, as I begin every task, with low expectations.

My finished dynel job, with 2 coats of epoxy on top

I have scuttled my plan to wait until the hull is flipped before installing the sheerstrake.  I had hoped to do so in order to give myself better sight lines and therefore a fairer sheer.  However, in one of my nocturnal cerebral spasms, it struck me that the outer stem and stern cannot be installed until the sheerstrake is in place, and the outer keel/deadwood cannot be installed until the outer stem and stern are in place.  So, it is on to the sheerstrake I have gone.

I decided a while ago, that I want to leave myself the option of finishing the sheerstrake bright, as well as the stem and stern above the waterline.  I saw some pictures of a Grey Seal finished that way, and it looked very cool.  Not sure if I can pull it off, as the scarphs must be perfect, and there is no margin of error (i.e., you can't smear on some more thickened epoxy to fill a gouge or dip.  Neither can you sand down a bulge without the inner laminates of the plywood showing through.)  In this regard, and so far, ONLY in this regard, is it more difficult to work with plywood than regular timber.

My decision to try for a bright sheerstrake has necessitated several changes in procedure.  First, I can't put temporary screws through the lands to hold the strakes together while the glue dries.  Instead, I made up a set of plywood U's with wedges out of some leftover scraps of mould material.

Aft port section of sheerstrake with new plywood clamps

 The other change was in my spiling technique.  I found that the simple plywood batten technique that I have been using up to now was not working perfectly when the plank curve was complex as it is at the sheer.  I am not sure why, exactly, but it left me with a plank that didn't have sufficient curve at its middle.  For the sheerstrake, I have gone to the slightly more complicated technique, which has been written up in books as well as Woodenboat.   I clamped an eight foot long batten on the top line of the lower land on strake #7, and another one on the sheer line on the moulds.  Then, using a hot glue gun, I attached short wooden strips at angles between the lower and upper battens.  After the glue hardened, I removed the assembly, laid it against my plywood sheet, and traced the outline.  It made a perfect plank, no fuss, no muss!  

My hot-glued spiled pattern for the sheerstrake

A word of caution about using hot glue in the summer, though.  The first time I assembled a pattern this way, I took it outside to my sheet of plywood on the sawhorses, and found that the sun had quickly warmed the hot glue enough so that my pattern began to straighten out.  If you use a brad at each junction, stay out of the sun, or use a glue stick with a higher melting point, that problem should be solved.

Although I have a bit more work to finish up the sheerstrake, I am thinking ahead to the stem and stern.  I plan to try a build-up method using mahogany boards rather than the lamination shown in the Grey Seal plan.  I guess I am getting tired of laminated bends, and also, the solid mahogany will look better varnished.  I am also thinking about the deadwood, for which I am tentatively planning to use douglas fir, if I can get some for a good enough price.