Rib Ends

Ric Altfather

WCHA #4035
I have researched a few methods of repairing/replacing rib-ends, at least for a few of the boats I have worked on. Now, I found an Old Town that basically needs every rib end repaired. From the experts, should I just cut below the inwale, lower the gunwale and end up with good wood on the ribs? This seems like the easiest but will it change the characteristic of the canoe?
Any advise is welcome.

Thanks,

Ric #4035
 
Ric - if you do choose that method, leave the inwales in place, don't cut below them. Use the old inwales as forms to clamp the new inwales to. Once you fasten the new wales with RS nails, then you can cut off the rib tops below the old wales.

You will be lowering the sides of the canoe by about 7/8" - 1" which will certainly impact freeboard and looks. Use you best judgement to determine if it is worth it based on value/rariety of the canoe, sentimental value and intended use after restoration.
 
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Mike,

Thanks, that makes sense but what are the alternatives? Scarf a new section in, fill with epoxy...what will look the best? The canoe has no sentimental value but it is planned for use and restoration. Nothing fancy just a nice HW Old Town.

Ric
 
Hi Ric,

How bad are they? Is it just the tips, or are the fasteners compromised? If the former, you can cut off the first 1/4" and glue in little tips. It will look good from above, and won't compromise the strength. If the ribs are split, but otherwise ok, you may be able to work epoxy into the splits and put a small clamp on the edges to pull the rib tight. How well you can get the splits to close up will determine the appearance when you are done.

Should you choose to scarf them all (and what a lot of work that would be!), keep the inboard edge of the scarf as close to the inwale as possible, and angel the scarf outward and downward. This will keep the visible scarf line tucked up under the rail where you won't see it from inside the canoe. If you can get a minimum of an 8:1 scarf (e.g. 2 1/2" for a 5/16" thick rib), you will theoretically have plenty of strength, the trick is to avoid hard spots, especially if the ribs have curvature coming to the rail. Your scarf angles on both pieces have to be dead on. Even though you theoretically have enough strength in the scarf, I worry about doing this to every rib in the canoe... seems to me it would set up a weak point in a major structural part of the canoe. Maybe someone who has done this can report on the results.

If you opt to cut the canoe down, try to keep the minumum depth to no less than 11" and preferably more. As you cut it down, pay attention to where the old fastener holes are, so they don't show when you are done.

Dan
 
Ric-
I echo what Dan said. I worry about the strength of having the gunwales, thwarts, seats etc all supported by scarfed rib tops.

If the wood is sound, but chewed up by nail & screw holes, you could try to fill with an epoxy/fine sawdust mixture then clamp with a board covered with waxed paper to prevent squeeze out.

Here are a couple of photos to illustrate the concept of keeping the scarf close to the inwale on the inside of the boat. You can actually see 2 different ribtop repairs - a scarf and replacement of the side of the rib where one part was sound, the other part needed replacement. I only had to do about 12 rib repairs and 5 rib replacements on this boat. Final interior sanding and 1st coat of varnish today!! :D

Good luck!
 

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Thanks!

Mike/Dan,

Thanks for the incite...Not sure what I will do. I don't want to compromise the itegrity of the canoe by cutting down the sides but sure seems the easiest. This is one of those projects that I need to walk away from for a few days and come back refreshed! Thanks again.

Mike, post a picture of that boat when it's done.

Ric
 
Just to argue with Mike C, the scarphs anything like the ones shown should be more reliable than dripping some goo into questionable wood. The scarph testing I've doen, admittedly not a set of rib tops, has shown that a decent 8:1 scarph will hold as good as the wood. If in doubt, or to reduce the worry factor, a few clenched fasternes in each would get you to the point that it wouldn't all fail at once, at least.
 
No disagreement, Paul. Most of the time scarfs are fine, and especially if reinforced with a clenched fastener. I just have this nagging distrust of having the entire boat done that way - plus it would take quite a while to pull off!
 
Good Thread!

Thanks to all for the good advice.

This has been an informative thread, some of which was lost in the great crash. Good info for those just investigating the web site. I have attached some photo's to give evidence to the problem of rib ends...chunks missing, the end missing, holes and rot.

Keep this one going and thanks again!

Ric Altfather
#4035
 

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Looks like a little TLC is all you need! It is really important to revive the info in the old threads. Everyone, but especially the newer folks can benefit.
 
Is it just me or do the rib tops look pretty good except for those cant rib tops?

I had to scarf a few rib tops near the decks and with the 1:8 rule (or close to that) I am convinced it is as strong as the original rib.

I used Dan's suggestion on the angle of the scarf and they are undetectable unless the canoe is upside down (or rightside up and the person is upside down!)

some photos here:

http://members7.clubphoto.com/eric520065/1482806/owner-ef36.phtml
 
Scarfing Technique?

Hi All.........
I agree with Cavy......It's great to revive old threads.
Oh, and to Mike and the "Old Curmudgeon," I'm gonna start doing my homework on a direct route to the Lake Placid brew pub. MapQuest?...GPS coordinates? Better yet, maybe I should just hitch a ride with you in 2006!

I'm working on an OT Yankee that has rib tip issues through out......
What have you guys been doing to make good scarf cuts on the rib and mating piece?


Dave
 
Scarf Cuts on Rib Tips?

I'm working on an OT Yankee that has rib tip issues through out......
What have you guys been doing to make good scarf cuts on the rib and mating piece?
Dave
 
Rib tip options

Here is an example of a lowered gunwhale on an 18' HW. The rot was into the stem tips and decks pretty bad so this HW had a retro fit low ender option and the sheer is 7/8" below origional. Suits me fine. So now you have something to campare to.
Regards, Dave.
 

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Dave - I used the little finger plane i bought from Roland. Since i had only a handful to do, I did each one with the plane, then fabricated the replacement piece - eyeballing it - and epoxied into place. I cleaned up the edges after the glude had dried. The scarfs are very very strong as the surface is so large and the forces on the ribs at those places is very low. I am convinced it is stonger than the original. It is not a large area to fabricate and can quickly be planed with a good sharp plane.
 
I also have lowered the gunwales.a replacement was clamped below the original then screwed in place All above was taken off with a sabre saw.
Like Dave says hardly made difference to the canoe around 7/8 lost.
The canoe I did had serious rot in either end and middle from being stored on the ground. Eliminated all the rot problems in one pass of a saw and nobody notices that it was done except me.
 
Wierd Rib Ends

Today, I removed sheer planks on this Racine. Two of the ribs made me chuckle. Look at the attached pictures.

The first two pictures show the third rib from the end is too short; it never met the inwale. My theory is that the boat was built on a Monday after Octoberfest weekend.

The third picture shows a room carved out of a rib by a bug. I think. Weird, huh?

Cheers,
Paul
 

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