The fillets do add a bit of strength, but for the most part they're there to make the cloth lay down without bridging across the panels and creating an air bubble underneath. I made fairly small fillets, about 3/8" wide or so, on my Tern and probably should have gone a bit larger. Some production stitch-n-glue kayaks I've seen have had fillets that were more like 1". Use a lot of filler material. If you do get an air bubble under the cloth, drill a small hole ~1/16" and use the syringes that Pygmy supplies to fill them with epoxy.

Dean

: we're about to glass the inside of the hull on heather's arctic tern. should
: we run fillets the full length of all the seams, or just in the ends of
: bow and stern. by the way, does a fillet add considerable strength, or is
: its purpose more adhesion and a rounded joint? thanks!!!