Installing gunnels?

[BWCA66]

So, now a couple more questions. To the builders who have glued gunnels - how long did you leave them clamped? How long does it take for the epoxy to gain sufficient strength to hold the gunnels to the curve of the hull?

For the builders who prefer screws - do you counter sink the screws and cover them, (plug the holes) ? Do you add any epoxy or varnish to the screw holes to seal them up before or after installing the screws?

Thanks John R

I always counter sink, always use stainless steel and never seal or cover them up. Just me but that's how I do it.

 

[dougd]

I also counter sink and use stainless steel as well. I had one boat that needed new gunwales and the fool who had it before me epoxied every screw head. Went through a few drill bits. I never coat the heads. I've never glued or epoxied a gunwale as I may want to take them off at some point in time and screws allow for that much easier. It's one of those personal ways of doing things I guess.

 

[Steve in Idaho]

A couple of days is long enough, according to most builders. A week in my book.

I just use screws for the inwhales. The screws, are driven flush with the hull, and then sealed by the outwhale, that is epoxied on..

Check the pics on page 2.

Great tip from Cruiser. Keeping things clean, saves a lot of work later !

Jim

I'm still in planning/learning phase, so this question may show my ignorance....
Jim - do you countersink those screw holes first - or do the screws compress the hull material flush?

 

[Jim Dodd]

I'm still in planning/learning phase, so this question may show my ignorance....
Jim - do you countersink those screw holes first - or do the screws compress the hull material flush?

Yes. I countersink them with a tapered bit and countersink. (In my pic above, those might be number 8s) I'm afraid if I didn't they would compress, and bulge the hull there, giving me more headaches
I use number 6 x 5/8" screws, now, stainless, or brass.
Some complain about adding extra weight, with the screws. They weigh next to nothing.

Jim

 

[Alan Gage]

Just a couple of details, I put a line of 1.5" painters tape about an 1/8" below where the gunnel runs before doing the epoxy work. Once the gunnels are clamped up, I use a paper towel or a gloved finger to remove most of the excess epoxy from the bottom of the gunnel .... the tape keeps this wiping off the hull .... this saves a lot of work, soft epoxy is easier to remove than hard epoxy. Also, if you use this, make sure you pull the tape after you are finished ... you want it off before the epoxy sets.

Brian

This is very good advice. You don't have to do it the other way very often to appreciate the time savings a little tape offers. Much easier.

When epoxying them in place I'd pull the clamps next day. Clamp at night and remove in the morning should be fine as long as your shop is warm. I usually waited until I got off work, so about 24 hours. You can use your fingernail on an exposed section of epoxy to see if it dents.

For screwing I countersink stainless screws so the phillips head is flush and don't use anything to cover the heads. Like others have said part of the point of screwing them on is so you can screw them off later. I've also never liked the looks of plugged screw holes. I'd rather see an exposed head then a mismatched circle of wood.

If screwing I varnish the edge that will be trapped against the hull before installation. I haven't been using any sealer on the screws themselves.

Alan

 

[Guest]

For the builders who prefer screws - do you counter sink the screws and cover them, (plug the holes) ? Do you add any epoxy or varnish to the screw holes to seal them up before or after installing the screws?

Late to the wood gunwale discussion. I have only done a couple or three canoes with wood gunwales, and can offer a more novice perspective.

Always screwed in place vs epoxied. Thinking that if I ever needed to repair or replace a gunwale, or even just inspect the underside and retreat, screwed in place would be easier than epoxied in place.

I countersunk the inwales, except the last couple screws at the stems which were countersunk on the outwales for easier drilling and screwing. Never plugged the holes, but heavily treated the inside of the holes using a pipe cleaner.

I always had a shop helper or two holding and bending the gunwales in place, with me one screw behind them as they worked their way up and down, up and down the gunwales from the center holding them together in place.

They held everything properly aligned, one holder near the screw area, one bending further up the sheerline towards the stem, while I drilled through the hull material into the outwale and set the screw. That alleviated the need for most clamp use and the installation process was surprisingly easy and straightforward.

The most difficult part for me was calculating and marking the spacing of countersunk holes, so that none of the horizontal gunwale screws came too close to intersecting the vertical machine screws from a hung seat, thwart or yoke.

I could easily move the thwart locations forward or back enough after the gunwales were installed so they were positioned between the gunwale screws, but the balanced yoke location was more specific, and the holes for a gunwale hung seat were equally tricky.

Having determined the best seat location within an inch or two, lets see, the machine screws for the seat hangers are 9 inches apart center to center and the gunwale screws 6.5 inches apart and oh gawd too much math to do on paper, my head hurts.

I ran a length of masking tape along the gunwales, clamped them it situ and marked the best yoke and approximate seat locations. A couple inches this way or that if needed with the thwarts does not much matter.

And then laid a tape measure along the wood and tried marking the gunwale screw spacing. And marking again, and nope not quite right yet again, until I had the spacing that best avoided a too close intersection of the yoke or seat hardware with a gunwale screw. If 6 inch screw spacing does not work how about 6.5?

The masking tape kept me from marking, Xing out and remarking hardware locations multiple times directly on the wood.

A couple years ago I was looking at a composite wood gunwaled boat on a canoe trailer, standing alongside the highly regarded designer and manufacturer, shooting the breeze while admiring his work when I happened to peer up from underneath and notice a resin plugged hole in the inwale. And there, a few inches back, a thwart.

I pointed at the plugged hole, gave him a quizzical look and shrugged my shoulders. He knew I knew the cause of those plugged holes, shrugged back sheepishly and said something like Yeah, thwart hole too close. We seemed to share a boatwork moment.

It was complete happenstance that I looked up inside the trailer rack from underneath while admiring his work, and more coincidental that I was standing exactly where I would see the epoxy plug. I got the impression he took me for an idiot savant at inspecting canoe construction.

We had established the idiot part earlier around the campfire, but I was not about to dissuade him from the savant part.