If you just go for a paddle than you can stop thinking about wanting to go for a paddle.

Sunday, December 18, 2011

2011: Post 66 – Oh the horror!

After I got home from Tuesday’s pool session last week I noticed there were a couple bumps in the skin at the keel between frames four and five of the Disko Bay.  I hoped there was just some debris that got under the keel, but I knew what was at that location, and I just had a bad feeling.  I walked over to the kayak and pushed against the bottom of the keel.  Yep! My suspicion was confirmed – the keel was broken at the location of the butt join!! 

I removed the floor boards, the backband and the stern flotation bag.  I got my flashlight and had a look.  There was a crack running horizontally in the piece of cedar that was glued on top of the butt ends of the keel pieces.  I have to point out that it was the wood that failed, not the gorilla glue that was used…



Notice in the picture how the grains are running horizontally in the joining piece. A rookie error; if I had turned this piece so that the grains would be running vertical to the keel this might have been sufficient to resist the pressures of the keel flexing when upon the water.  I conjured up a couple options for a fix and decided on one.

I could not get my arm far enough through the hole in the frame in order to reach the join location and so I had to cut away a piece of the frame. 



I filled the crack with gorilla glue and braced a small length of wood against the keel and frame and wedged in a piece of scrap wood to apply enough pressure so as to force the crack to close together.  I let this sit for a full 24 hours.




The next night I removed the length of wood.  As expected, the glue was holding. 



But this would obviously not be sufficient as the same thing would just happen again.  I scraped away the excess dried glue on the sides and sanded the surface on each side as best I could.  Then I cut a couple pieces of leftover 11.5 mm thick Russian birch plywood and sanded the corners.  I buttered up one piece of plywood with marine epoxy and clamped it in place.



Then I buttered up the other piece of plywood with marine epoxy and put that in place.



I had a look at what I had done and figured this should be sufficient to fix the problem, assuming I had a good bond for the full length of the plywood. 



But then this morning I had another look at it and decided to epoxy in a piece of wood into the gap at the back of the plywood with a piece of cedar.  I had another piece of cedar lying about that was just about the right length and its grain was more vertical (actually diagonal) so I decided I would epoxy this on top.  These extra pieces are probably just overkill, but they cannot hurt.  



I’ll stop adding in pieces of wood now.  I realize this whole thing looks like just a conglomeration of wood pieces… Skilled woodworkers and kayak builders looking at this are probably cringing… Oh the horror!!  But I profess that I am neither and I do hope this ‘fix’ holds. 

When I started my Disko project I intended to do as good a job as possible, given my lack of knowledge and skill in the endeavor, and use it as a learning experience in SOF kayak building, and kayak building in general.  I hoped it would turn out decent enough to use in the pool and at St. Philips in the cove, maybe take it on some short paddles.  I think it turned out far better than I had hoped, at least looking at it from the outside… 


But I wonder now about what is under the skin.  Will this fix hold?  Will the other joins hold or will they too suffer the same fate?  Usage and time will tell. 

2 comments:

  1. Well, that's too bad. In the meantime, I can't get my head around how it happened!! Shouldn't the chines,gunwales and back deck stringers be taking a lot of the strain as well? How much flex occured in the hull to cause such a short piece of wood to crack - even if there was a possible problem with grain orientation? I'll admit that I never paid any heed to grain in my boat as I figured the fuselage construction spread the stresses out over a number of frame components, i.e, stringer, keel, gunwales and chines.

    Given the splints you just installed, I can't see this being an issue anymore!!

    Sean

    ReplyDelete
  2. I know what you are saying about all the stringers in that location... The only difference I suppose is that you doweled your stringers to the frames and mine is all just lashed... perhaps I have more flexing in my frame???

    ReplyDelete