Building a Wood Duck 12 - Exterior glass

I once read a book which ended with the hero getting set to go to certain death. The sequel opened with him in a bar, drinking with some friends. One asked him how he managed to cheat death. He modestly replied that it was no big deal, that it wasn't even worth talking about. It was never mentioned again.

I'm afraid that the story of how I taped the deck to the hull will have to be like that, too. Basically, I followed the instructions in the manual and it all worked out just like the manual said. Except for the rear compartment. Between the safety gear, the lamp and my shoulders, there wasn't any room left back there. Eventually I had to ditch the safety gear and the lamp and use an old flashlight. I got the back taped, too, but it wasn't fun. I had a headache and runny eyes the rest of the day from the epoxy fumes.

Then for some reason I didn't take pictures of the exterior glassing of the hull. I think that it was a time constraint. No loss, though. It was done exactly as the manual describes it. So this page starts with the glassing of the deck, in which I show a neat trick to avoid sanding the edge where the top & bottom glass overlaps.

Click on any image below for a larger view

Masking the glass

For maximum strength, glass joints should overlap at least 2 inches. This provides sufficient surface area to distribute the tensile forces trying to tear the joint apart. The problem is, this can leave loose threads and a messy edge which requires lots of sanding and fairing. It's not so bad when painting, but for a bright (varnished) finish, it's a real nuisance.

Here's the trick I promised - run a band of plastic packaging tape around the the whole deck, 2 inches below the sheer. This will keep the glass & epoxy from sticking beyond the 2 inch point.

Draped duck

All ready for the epoxy. All the corners were sanded smooth with curves instead of sharp edges to allow the the glass to smoothly transition from the deck to the hull.

Excess glass peeled up

The epoxy was applied with my favorite technique of spreading it out with a gloved hand. Once it cured beyond the tacky stage to the "green" stage (rubbery, leather-like, stiff, etc.), I gently peeled up the glass from the packing tape. You need to pull strongly enough to peel right to the wood, but gently enough so as not to peel away from the wood.

Excess glass torn off

This part's really fun. Use a razor knife to start a tear right at the point where the glass is attached to the wood, and start pulling back the glass. It will (for the most part) tear cleanly away from the wood leaving only a small ridge of fuzz. If the tear departs from the wood line, as it did in the picture, just restart it.

Again, tear carefully. You need enough pull to propagate the tear, but not enough to peel away from the wood.

Edge finished

As soon as all the excess has been torn off, immediately remove the packing tape. Otherwise it will leave an adhesive residue. Then let the glass continue curing for at least another day to make it hard enough to sand.

Once it's cured, give the ridge a very light touchup with some #220 sand paper. This is what it ends up looking like. It's all ready for the weave to be filled.

Wood Duck graphic

The edge finishes up very cleanly. Here it passes right over the wood duck graphic that I put on before the hull and deck were glassed, with no interference at all.

Page 1 - In the beginning
Page 2 - Hatching a Duck
Page 3 - Stem & stern pieces
Page 4 - Interior fillets & glass
Page 5 - Glassing under the deck
Page 6 - Installing footbrace mounting studs
Page 7 - Building the coaming, attaching the deck
Page 9 - Graphite bottom, invisible hatch hold-downs
Page 10 - Final outfitting

Copyright © 2009 László I. Mórocz. All Rights Reserved.