the use of fiberglass drywall tape

Please excuse the other George's hyperbole. This tape has something more than zero strength in epoxy. Newspaper has more than zero strength when layed up with epoxy. If you want to make a pinata that the kids will never break, use epoxy for your paper-mache. The real question is does it have enough strength in this application? I feel that the destructive testing I have done assures me that it does. Are some of the seams going to open up if you try to white water? Yes. Have it fall off the rack at 60 MPH? Probably.

There's an interesting study being done by a Prof. at the Naval Academy concerning the deterioration of fiberglass sailboats. Sailors who sail their boats hard complain that they go "soft" after time. What this study shows is that softness can be measured. It concludes that the millions of tiny impacts from waves and the repetitive stress of rigging loads creates micro-fractures in the resin leaving the glass cloth free to "pant" and flex. This is felt by the sailor as softness. Load up the rig and the boat bends like a banana. The sails can't be properly trimed and the boat is no longer competive. One reason for this failure is that polyester resin has only about 1/6 the strength of the fiberglass matrix it is trying to keep rigid.

So if people think that putting 6 oz. tape on the seams of a kayak is the only acceptable way to go I disagree. The tensile strength of the tape is far in excess of what's needed to tie these panels togther. This means unnecessary weight, cost and finishing time. But as they say the proof is in the pudding.

This is my first yak (see pix). It was built in '96 of 5mm lauan with ash trim. I used fiberglass drywall tape for the seams. This picture was taken last summer. You can see the seams ain't popped yet! I gave it two coats of WEST epoxy, faired the hull with polyester resin mixed with WEST 410 and painted it with acrylic enamel.

The boat was a gift to the jughead (Ret.) in return for his hospitality. If you were in country in '68-70 you might recognize Tom. Don't worry about the paddle, he just found the Greenlander he made a little tight with the retriever aboard. Apparently infected by the gift, Tom says he wants to try his hand at a stripper.