Repairing cracked ribs

Joined
Jan 31, 2013
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Warren, Manitoba
What to do with a cracked rib that is not broken completely through? Sure, we could bend up a new rib but that takes a fair bit of time and material. There are other ways. We could cut out the cracked section and splice in a new piece from the inside, or, in this case, we go in from behind. Sure, we will still be able to see the crack from the inside, but we keep the original wood and colour and know it will not open further in the future.



First, remove the planking from behind the rib(s) to be repaired. We use small cutters with the nose shaped better, carefully work the tips in under the tack and pry gently. Once you have it partially out, give it a wiggle to see which way it wants to come out. When they get clinched, the tips will bend a certain way, so it is best to find which way the tip is bent with the wiggle and then turn it out of the planking and rib in the direction it wants to come out.

Once you have the planking removed you can start the process. I am still working on technique, I haven't done many like this but stepped up my game a bit today. Normally I have used a Dremel router to remove the material for the groove in the back of the rib, but with mixed results and many burned out bits. So today I made up a jig for the slot I wish to make and stepped up to a proper router, but you need to be careful setting the depth since we only want to go about half way through the rib.



So, set the jig up over the crack and remove about 5/32" of material to create a slot in the rib back. I try to have it taper out to flat on the ends but if that doesn't work with the router I finish up with a flat gouge and sand if necessary.



Once we have the groove how we want it, we need a wood filler piece. I use white cedar but you could use a thin piece of hardwood as well. The cedar is easier to shape after glueing though and if you use hardwood, you will need to pre-drill it to put the planking back on.

I cut a piece of new planking slightly wider and sand it down to fit snug in the groove. I then pencilled on the taper at each and and shaped it on the bench belt sander close to the finish needed, then I glue it in and clamp.



On the two present boats I have started to use T3 instead of thickened epoxy. The T3 allows for more work to be done in less time as the epoxy needs overnight to cure. I'm not certain about the issue of the T3 and water so I will do my best to ensure it is well sealed and away from water contact.

 
Joined
Oct 27, 2012
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137
Location
Ottawa, Canada
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It's a good idea. I used it in 2011 for a cracked rib on my old huron. I really liked the idea because I had no idea on how to fake a new rib into looking old like the others. This left the top rib intact complete with patina and old black tack holes.

rib-repair.jpg
photo598.jpg
 
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Joined
Jan 31, 2013
Messages
2,291
Location
Warren, Manitoba
Lee Valley sells powdered stains in 30 colours. At some point later this year I will get some and experiment on matching new wood to old. I figure if I varnish an old piece and a new piece, I can take those in and get their opinion on which colours would be best. It has to be after varnishing since even with bleaching the old wood it will take on a lot of the old colour, it just hides well after sanding. At $9.95 an ounce I want to get the right ones from the start.

After I did the first one in the photo's above, Christine did the other two, so we have something else she has learned on fixing old canoes.

Karin
 
Joined
Jan 8, 2014
Messages
1,133
Location
Minden, NV
Not a bad solution. As long as you have the canvas off, why not just replace the broken ribs? Unclinch the nails and leave the planking in place. Remove the busted rib and steam a new one to fit. Worrying about the color of the new ribs and old ones is a waste of time. You can either remove all of the old shellac and varnish and start fresh. Or use a product like Formby's which will dilute some of the old finish and allow you to move it around on to the fresh ribs.
 
Joined
Jan 31, 2013
Messages
2,291
Location
Warren, Manitoba
Don't always need to replace the entire rib if the crack doesn't go all the way through, depends on the boat. We did replace a couple of ribs on that boat and now have pulled 4 more to replace since a prior fix corrupted the bottom, making waves down the length.

When I get the Morris next weekend I will have to decide if behind the rib repairs will suffice or will I need to replace all 28 cracked ribs?

Have 3 on the go now, 2 more on the way, I love this!
 
Joined
Jun 30, 2014
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1,550
Lots of reasons to not replace a rib but on this boat it is being used as a training aid for me so I thought I would try some. Normally on one like this that has no real historic value we would yank it out and replace it. If there is a huge crack, or multiple cracks, then out it comes. But these were only part way through and it saves us some hard to acquire white cedar by fixing as opposed to replacing.
These are nice little boats but nothing special and having a mismatched colour scheme is no big deal, we just try to do our best no matter what. Some of the ribs I took out yesterday were the wrong size, shape, width, and material. They worked but it screwed up the hull by not being in line with the others. Aggravating. So yeah, out they came.
No hurry, I have lots of boats to paddle.

Christy
 
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