Please read the Legal Disclaimer.

Gunnel Replacement
By Mike McCrea

Here is my take on replacing gunnels:

These are instructions for installing replacement plastic gunwales, the technique is similar for aluminum gunwales. Wood gunwale replacement, involving both an inwale and an outwale is a slightly different beast. Finding 16 foot + lengths of ash for replacement gunwales on tandem canoes at a reasonable cost is near impossible, so replacing worn out wood gunwales with plastic or aluminum gunwales may be an option to consider.

Start by taking out all the hardware, taking off the old gunwales and - THIS IS IMPORTANT - marking all hardware (bolts, screws, etc) locations on both the inside and outside of the hull. You'll want to re-install the seats and thwarts in the same locations, you'll want to avoid hitting the same holes when you pop rivet the new gunwales back on. So mark all the old screw or pop rivet hole; when you install the new gunwales you can space out the new pop rivet locations so that you miss the old holes and also avoid intersecting the seat or thwart hardware.

But, before we begin, while you have them off the boat, sand down the old seats, thwarts and carry handles if they need work. After you sand ‘em, stain 'em.

If this is a fiberglass or kevlar/composite boat you'll want to lay a strip of glass over the old pop rivet holes before installing the replacement gunwales (if this is a plastic boat you can skip this part of the process). Two inch fiberglass tape (fiberglass with a seamed edge) will work best for this covering the old holes on glass or kevlar boats. You'll be applying the seamed glass tape to ONE side of the canoe hull interior at a time. Measure the length of one side of the hull and pre- cut a piece (or two) of fiberglass tape to length.

Prop the canoe up on its side. Securely; it's a bitch if she falls over when you are holding 4 oz of resin inside the hull. I have a set of sawhorses with locking swing arms to hold boats in any position...prop her up with an old L bracket screwed into the top of the horse or whatever, just make sure she won't fall over.

Mix the resin in some graduated container (or not...if you are using West Systems...it's good stuff, but expensive). You'll need @ 1 oz of resin per 4 feet of 2" tape (or, for future reference, about 1 oz of resin per 3 feet of 4" tape...but you don't need 4" tape for this job). So, mix the appropriate amount of resin.

Next you'll need a shallow (maybe 2" or 3" tall rectangular container...go in the kitchen and steal a Tupperware container from the wife) So, take the resin and the pre-cut piece(s) of glass tape. Lay a section of the glass tape in the bottom of rectangular container. Pour a little resin over it. Lay the tape back across that tiny puddle of resin, nice and flat. Pour a tiny bit more resin. Lay more tape over it. Resin. Tape. Resin. Tape. When all of the resin & tape in the container your wife will walk into the shop asking if you've seem her Tupperware. Say "No". When she leaves squish the resin/glass tape "lasagna" around to thoroughly saturate the glass. Remember to put on latex gloves first next time, fool.

Walk to one end of the boat. Kick the damn cat on the way. Pick up the loose end of the resin saturated glass tape in one hand while holding the Tupperware in the other. Slowly walk along laying the wet glass out into position on the hull; allowing the tape to pull smoothly over the edge of the Tupperware container will gently squeegee off most of the excess resin. If you have extra glass when you get to the other end (and you will, saturated glass will stretch a bit...but better to have a bit too much than a bit too little) just layer it back over on the same side. Don't block the lining holes (if the boat has lining holes...if it doesn't you can always add ‘em while the boat is drydocked in the shop).

While the resin is wet adjust the positioning of the glass tape as needed to make certain all of the old screw holes or pop rivet holes are covered, but don't let it stand above the upper edge of the hull. A cheap, disposable paintbrush works well of this repositioning, and you can use it to brush any excess resin on spots that look a little thin (you'll have some resin left in the Tupperware container).

Wait for this to dry sufficiently (a few hours to half a day, depending on the temperatures and amount of hardener used). Buy wife new Tupperware. And flowers. Turn the boat onto the other side. Repeat above steps on this side. Wear gloves this time.

Hey, is the stain dry on the seats & thwarts? Great, put on the first coat of spar varnish.

Wait a day or two. Take a palm sander (or hand sand) and smooth out the bottom seam of the glass tape, where the seamed edge stands a bit proud. Lay a strip of painters tape about 1/2" below this seam. Re-coat the sanded seam and the area above the painters tape lightly with resin; the painters tape will give you a nice, straight line of resin coloration inside the boat (instead of a sloppy, brush-strokey edge). Pull the painters tape out before the resin sets.

(If you are installing new gunwales on a plastic boat skip all of the above glass tape & resin instruction and start here)

OK, the hard part is done. Have a beer. Or, if this is like working in my shop, have yet another beer. While your having that beer make yourself useful - lightly sand down the 1st coat of spar varnish in the seats & thwarts and apply the 2nd coat of varnish.

Now you're ready to put the replacement gunwales on. It helps to have 4 hands. Unless you are built like some Hindu goddess, invite a friend over...you supply the beer.

Slip the gunwale in place, starting at one end and working down to the other. Now you see why you need four hands. Now slip the other gunwale in place. Take a rubber mallet (or hammer and a block of wood) and tap the gunwales back or forth into their final position, evenly spaced. Lay the deck plates on top of the gunwale ends. Notice the molded indentation where on the side of the deck plate where the gunwale slips in? Tap the gunwales back in one direction 'till they fit right up to this molded indentation. Cut off any excess gunwale on the other end so it doesn't stick past that molded ridge either. Put the deck plates back on the bench for now. Hey, that's a great song, turn up the shop radio.

Start pop riveting the gunwales on in the middle, one side at a time. Work your way along the side in either direction from the middle. Drill a hole, pop a rivet. Make certain the gunwale hasn't slipped up. Drill a hole, pop a rivet. make certain the gunwale hasn't slipped. DON'T DRILL ALL THE HOLES AT ONE TIME - THE GUNWALES MAY SLIP OR SLIDE A BIT AND YOU'LL HAVE A MESS. AND DON'T POP RIVET FURTHER TOWARDS THE BOW OR STERN THAN THE SEATS JUST YET!

Pop rivet on both gunwales this way, stopping at the seats. Now slip the free, unpopriveted gunwale ends off the hull and into the deck plate channels and struggle to get this assembly fitted over the hull. When it doesn't seem to want to go, hit it gently with a rubber mallet. Once you've got it in position remember that you were supposed to install the rope lining loops BEFORE putting the deck plates on, so you could tie the knots inside the hull under the deck plate. Take the deck plates back off. Install the ropes through the lining holes, tying the knot inside the hull. Now put the deck plates back on. Pay attention next time.

OK, finish pop riveting the gunwale on. But, if this is a glass or composite boat, when you get to the section of the deck plate at the very end, the section that doesn't have a gunwale inside it, the pop rivet will be going through just the deck plate and the glass hull; you'll need to back up the pop rivet with a stainless steel washer (otherwise the pop rivet will most likely snap the fiberglass). It probably wouldn't hurt to back up the pop rivet in these locations on a plastic hull either.

OK, you're almost done. Go sand down the seats, thwarts and carry handles again and re-varnish 'em. When this coat of varnish is dry debate putting a 4th coat on. Screw it, put the seats, thwart and handles back on* and go boating instead!

Yer done.

Nice boat.

Let's fix another one!

* The thwarts and carry handles do not span the entire distance between the hull - AND THEY SHOULDN'T. These pieces should come just a tad shy of the inside of the hull to allow for some flex without banging thwart to hull. I use tongue depressors as spacers when I'm repositioning thwarts to make sure they aren't up tight against the hull. Bolt the thwart in place and then pull the tongue depressors out.

Return to previous page