C-Forum

I have stumbled across some mention of drilling holes in Royalex larger than the screw holes in ash gunwales to keep the chances of cold cracks down. Just wondering if anyone has any experience with this and how effective it is. Would it keep me from having to loosen the screws every winter? Or even better, could I then use the boat for winter paddling? Or does it just simply decrease the chances of cold cracks and I should still use caution storing the boat outside?

Also I am installing ash gunwales on my L'edge. I think I have a pretty good handle on how to do it however a few questions. Is it necessary to steam or soak the ash to bend it for the install? Or can it just be fastened from one end to the other bending slowly as you go down the line? Also, any idea as to the actual name of the (what looks like to me) stainless steel screws that tend to be used for gunwales? Knowing the name of them may help me track them down.

Thanks

Living in Michigan, I always slotted the last four or five holes (about 1/4"-3/8") and never had problems. It's not so much the cold as it is big changes...well below freezing at night to 30 degrees in the day kind of changes...or going from heated house to freezing outside. If you weren't using your canoe in the cold months removing the end few screws would be ideal, but who can let their boats just sit .

As for the Ash, just get some c-clamps and clamp and work your way along. The ash will bend easy enough.
For the screws, just go to your local hardware and get some #8 SS Woodscrews 1/4" shorter than your total thickness...probably around 1 1/4"-1 1/2" long
Mikey

Cold cracks aren't going to be an issue on a short boat. I know a few folks storing and paddling sparks in sub zero (metric) temps without issue.

There's no need to soak or steam the gunnels for the l'edge. Aside from the very ends, the gunnel line on the l'edge doesn't curve much at all. Getting the final bend at the bow and the stern can be a challenge if you ve kept part of the deck but it's doable with a really big C-clamp and some patience. I would consider using machine screws and washers for the last couple of holes. Otherwise they may pull out of the wood or split the gunnel.

Usually when you gunnel a boat, you don't start at one and end and go to the other. You usually start in the middle, add your thwarts and then work your way out.

FWIW, I have 2 Royalex boats with wood gunnels, neither of which have enlarged holes. One of these sees even sees a few days of river between December and March and I've never experienced a cold crack. However, my boats are stored in a garage and don't see the extreme temperature swings an outdoor stored boat would. If stored outside I might consider doing it.

I agree with Ian to use machine screws or some type of bolt with a nut at the ends. There is a lot of tension - I popped the screws on my outrage

As to the screw part of the question I'd steer away from stainless steel. They tend to be too soft, too easily bent, too easily stripped, not have good threads for a good grip in wood, and expensive. Other than that, um, perfect!

I've been experimenting with good success so far here:

http://www.kregtool.com/PocketHole-Scre ... dlist.html" onclick="window.open(this.href);return false;

Note they make weather-resistant types. You may not find the right length at your local store but they can be ordered. I especially like how the undersides of the heads are flat rather than beveled -- much less splitting / getting buried in wet wood potential.

Beware the aggressiveness of the Kreg drill bits though. You need to use a stop to keep them from digging in too deeply.

Ken Dubel

Sometimes it isn't the screws themselves that cause the problem, but rather the wooden gunwales pushing on the stems of the boat. I had a Dagger Legend that could not be reassembled in temps below 40F because the hull had shrunk so much at those temperatures that the inside gunwales (sometimes called inwales, eh?) couldn't be jammed back in. I fixed this by shortening the inside gunwales. I also slotted the screw holes in the hull at either end. If you work the boat at all in cold weather you will find those holes starting to elongate themselves anyway.

I have seen cold cracks in Royalex hulls. I suspect the problem becomes more likely as the boat gets older and the Royalex more brittle. It seems prudent to avoid any undue stress in the boat (and in your life) and doing something to relieve the stress caused by unequal expansion ought to be a part of good boat maintenance.

Thus reasoneth Hank.

Thanks all!

Here is the finished product. Thanks for the help.

Nice. One thing I do with those wide finish washers holding the thwarts is bend the inside down with a hammer 'till they're flush with the inwales or grind that inside off & reattach... less chance of cutting yourself or your suit.