Page 1 of 1

Splicing a broken wooden spar

Posted: Sun Jul 05, 2015 10:08 am
by tmoobear
Hi everyone,

I am getting around to fixing my two broken gunwales on my circa 90's Nautiraid Expedition.

First, Has anyone had the problem of not being able to unfold the spars due to swelling of the wood? When assembling mine a year ago on a very humid day, I tried forcing the gunwales into their rigid position. Both of them broke through the holes with the brass rivets.

A knowledgeable friend of mine helped me splice on two new end pieces. Wte cut the gunwales off on the broken pieces at a steep angle and then used, maple, I think to make a replacement end piece with holes drilled to accept the rivets. I will now varnish them and only need to find brass rod to replace the rivets.

My question: Has anyone had this problem before with spars swelling to the point of not being able to strraighten? Do you think that a large glued surface will be enough to hold the new wood to the old? Could stainless steel screw and bolt be an acceptable substitution for brass rod?

Thanks for any and all help!

Re: Splicing a broken wooden spar

Posted: Mon Jul 06, 2015 2:30 pm
by ChrisO
I have gone through the same issue with my Miniraid.
I feel that the issue is not so much the swelling of the wood pieces, but rather some shrinking of the skin (at least on my kayak). I have had the gunwales split at the hinges twice. These hinges are the weak link in the frame.
The best repair has been to not only scarf on new wood, I used a new piece top and bottom, but also to cut two slots in the horizontal plane into the gunwale ends. These slots get reinforced with epoxy saturated fiberglass mat. The reason for the fiberglass reinforcing is that there is very little wood around the rivet at the hinge, it tends to split again! I replicated the brass rivets exactly. A bolt might be OK, just use one with a rounded head, so it does not dig into the deck.
Whether the scarf holds or not depends on scarf length and glue used.
In addition, I am making a spreader bar for the frame to be inserted between the forward and aft deck beams to spread the frame a bit and stretch the skin during assembly. Idea is to not have to bend the gunwales quite so far during assembly. I use this same principle on my old Kette, where this is the required method.

Hope this helps!

Chris O.

Re: Splicing a broken wooden spar

Posted: Wed Aug 15, 2018 9:44 pm
by tmoobear
hi Chris,

Sorry to get back to you so late! i am finally geting around to making the necessary repairs to that broken spar. You are probably right that it wasn't due to the humidity that day but to the inherent weakness of that joint. I think I will try the reenforcement of the gunnel ends with fiberglass. Thanks for that invaluable idea! I will let you know how it goes!

Thanks again, so much for all of your excellent suggestions. I will let you know how it goes.

Other than that, how do you like your Nautiraid?