Boat Building Forum

Find advice on all aspects of building your own kayak, canoe or any lightweight boats

Re: protecting the bottom ( PART 2)
By:Paul Jacobson
Date: 7/23/1999, 9:34 pm
In Response To: Re: protecting the bottom (Paul Jacobson)

Continuing where I left off:

> With stitch and glue construction and plywood panels the seams are
> typically covered with two or more layers of fiberglass tape and resin. (
> epoxy or po

polyester resin. This should be sufficient to protect the seams.

Since the center seam ( along the keel line) is the area that is most likely to hit a sand or gravel beach you already have a durable armor in this spot.

The sheer line (which is also a well protected seam joining the sides and the deck) will probably be the area that gets the most abuse when docking. Same goes for the bottom chine line, which is the joint between the sides and the bottom of the hull.

Between these lines you have a durable plywood panel which is usually sealed with two coats of epoxy resin. While this coating is not reinforced with additional fiberglass fabric, the resin does tend to soak in, seal the wood fibers and toughen the wood, making it more resistant to scratches.

Again, if you find that these areas are getting deep gouges you can always go back to the workshop and add another layer of fiberglas cloth and resin to `armor plate` the bottom.

After all the work with fiberglass cloth and resin that you will do in construction of your boat you will be an expert at doing this little task should the occasion arise, and it will go very easily.

As for adding a truck liner layer. The stuff is heavy and thick. If you are planning on bouncing off of a lot of rocks (whitewater) you might try it. I would put on a light sealing coat of epoxy resin on the wood. Then, when that had set up I would lay on my single layer of 4 ounce glass cloth and put on two coats of resin. The first would wet the cloth, the scond would not be enough to fill the weave. I'd leave it a little rough, and do some sanding with coarse sandpaper to have a nice rough finish before I took my boat to a truck bed sprayer. I would carefully mask the areas I did not want rubberized.

Strange timing on this letter. I just picked up a sample of the rubber lining for truck beds yesterday, and was commenting to a friend on how it might be nice stuff to use for waterproofing the skin on a skin-on-frame style of kayak. I could use a very light fabric for the skin as the truck liner material seems quite durable all by itself.

Talk to the people who do the spraying. The samples I'v eseen seem to have a pebbly appearance, kind of like they sprayed it with a clear plastic that beaded up. From a distance it looks like rainwater beading up on the black rubber, but those `beads` are solid. You might want a smoother finish.

A friend with a fiberglass Old Town canoe decided to add a rubberized strip about 4 inches wide from the bow and stern down the centerline of the hull for a few feet at each end. He says it doesn't seem to help deflect scratches, and just adds another pound to the portage weight.

Hope this helps.

Paul G. Jacobson

Messages In This Thread

protecting the bottom
romuald thorn -- 7/23/1999, 7:37 pm
Re: protecting the bottom
Paul Jacobson -- 7/23/1999, 9:08 pm
Re: protecting the bottom ( PART 2)
Paul Jacobson -- 7/23/1999, 9:34 pm
Re: Re-glassing over paint
Don Beale -- 7/24/1999, 1:19 pm
Paint? What paint?
Paul G. Jacobson -- 7/24/1999, 8:08 pm
Re: protecting the bottom
John Herr -- 7/23/1999, 8:17 pm