I built my kayak from Nicks book about 12 years ago. I cove & beaded all my boards. This allowed for easier alienment of the halves. I joined the two halves in the same process as glassing the lower half; I left a 2 inch overhang which, after banding the halves together I layed the overhang onto the upper half. You have to have everthing right at hand and work quickly. After that cure I glassed the bottom half overlaping on to the top 2 inches. I think this was easier than taping.
Why not try a small laminating roller or similar to wrap the joining tape around it will roll out much easier than using the brush, also You really need to use at least 2" tapes for a joining strip as there appears to be only half inch either side here?
Very fiddly. More room inside than the RC yachts I normally build. Wouldn't it be easier to glue and glass a 40mm wide overlap strip to the deck or bottom and simply glue the two halves together?
Polyethylene is very bad properties for bonding with paint/glue/resins. This is because its surface tension. It is possible to chance the surface tension by a process Called "Corona treatment"
