MacKenzie 20' Canoe (My First Canoe)

[Benson Gray]

I agree with MGC that these look like old cracks that may have already been repaired from the back. If these have not been repaired then a common approach is to 'sister' the rib as Fitz described. See http://www.wcha.org/forums/index.php?attachments/39097/ for one example. It is not unusual to add a complete new rib on top of the old one as a temporary repair. Good luck,

Benson

 

[Canooh]

Thanks Benson, MGC, Greg, and Fitz; those are some great insights and suggestions. I gather the big question is whether these ribs at issue were broken before Tom's repairs (and, thus, already have backside repairs applied) or, alternatively, these ribs were broken later, varnished over, and something I need to address sooner. I read discussions about the backside repairs in some links Greg posted, so I get the general idea of some methods which may have been used. I'll investigate further to try to find indications of prior repairs. I will consider sistering to one or more ribs. Unfortunately, I see unstained plank wood in the crack in the planking right beside a rib, so that is a possible indication of the rib flexing too much there and breaking the planking. The worst rib is broken on both sides. I'll plan to pad the area forward of the rear seat (and likely other areas of the canoe) and avoid putting my knees and other heavy items in this area.

I have a structural engineer buddy and he has always told me a proper sistered member is much longer on both sides of a break than is commonly understood and applied. From the perspectives of strength and aesthetics (ignoring weight for a moment), it seems to me a full-length rib sistered on top of the broken ribs would be ideal. I wonder if I could reasonably create a much deeper and wider rib than the one being sistered to and then rout out the underside of the new rib, such that the new rib would fit completely over and wrap around the broken rib--that might be better characterized as a "mothered", rather than a "sistered", member. The tops/ends of the rib would be something to address, but maybe it somehow fit all the way into the gunwales (maybe on either side of the covered broken rib) or it could even taper to nothing near the gunwales. Is that too crazy a repair? Until I find out the canvas needs to be replaced for its own failures, I really have a problem with the concept of removing Tom's professionally-installed canvas, which may otherwise be good for many years to come, solely because some broken ribs might be a problem in the future. At any rate, I think sistering (or even mothering) is something I want to look more into, especially since I could do a lot of the work of preparing one or more ribs before having to make the decision to alter the canoe.

 

[MGC]

I gather the big question is whether these ribs at issue were broken before Tom's repairs (and, thus, already have backside repairs applied) or, alternatively, these ribs were broken later, varnished over, and something I need to address sooner.
The tops/ends of the rib would be something to address, but maybe it somehow fit all the way into the gunwales (maybe on either side of the covered broken rib) or it could even taper to nothing near the gunwales. Is that too crazy a repair?

The breaks were there before the canoe was canvased. They are not new. If they were not backside repaired, then Tom would have made a deliberate decision to leave them as is. That would suggest that he did not assign big risk to leaving them as is. You can opt to sister a patch over them if you are worried about it.
Is patching a whole rib over the top crazy? That's a harsh way to describe that fix, but it is certainly equivalent to killing a mosquito with a snow shovel.
I once looked at one of Rollin Thurlow's personal canoes and noticed that he had repaired a rib with a small cedar patch and small brass screws. As all things Rollin, it was neatly done, matched the width of the rib, tapered/smoothed on all sides and no more than 2 or 3 inches in length beyond the crack on both sides. The idea is to spread any load on that crack across the rest of the adjoining rib. I'd lean towards a similar repair if one is required.

In an earlier post you inquired about the blend of heated materials I apply to a hull prior to canvassing. That blend I use (turpentine, linseed oil and mineral spirits) is only used on the outside of the hull before canvasing. The inside of the hull gets coats of thinned varnish followed by progressively less thinned varnish. Maintenance coats of varnish are applied as needed. Your canoe does not look like it needs to be varnished.

 

[Canooh]

MGC, thanks a lot. I'll keep a watch on the area with the series of broken ribs and determine whether to sister to one or more of the worst ones in some fashion, understanding a full mothering of the rib is probably overkill. Thanks for the clarification about the hull treatment--I have been wondering about that. With my paint seemingly in good shape, I guess I can just wax it? I see some conflicting information online about avoiding wax which contains silica? I wonder if this new ceramic wax they sell for cars would be beneficial. I also see some people who claim spray on wax is best. Any thoughts on a protective layer to apply to this paint?

 

[MGC]

Maybe someone else can chime in about waxing hulls. I don't generally do anything other than occasionally washing them with dish detergent.
A good paint job is more than adequate.
If I did wax the hulls I would apply a marine wax, and one that does not have silicone in it.
Don't get me started on the ceramic finishes. I use Griots Garage carnuba on my Boxster.
Silicone is the bane of canoe maintenance. Paint, epoxy, glue etc. won't stick to it.
If you ever need to touch up a hull that has had silicon applied to it the result will be holiday city.
Even with good preparatory sanding silicon will remain to repel paint. Little fisheyes that will appear in your finished paint job.

 

[Dan Lindberg]

If this were my canoe, I'd be inclined to paddle it and do nothing to it for a while. (if Tom was happy with it, it doesn't need anything)

As for wax, I'd paddle it first.

Silicon - don't let it in your shop/garage much less on a canoe.

Oh, and paddle it, spend some time in it before you do anything.

Dan

 

[Canooh]

Thanks MGC and Dan. If all goes well, she'll be in the water tomorrow.

FYI, one reason for the wax inquiry is the red staining mud we have in NC. It isn't just an issue when directly touching the mud, the iron and mud are suspended in the water. Nothing light-colored which enters our lakes leaves unstained. I won't worry with it today, but I'll look into non-silicone wax options. In searching, it seems a bit difficult to verify silicone content on many marine waxes.

 

[Canooh]

Oh, @MGC, it seems even Griot's Garage natural carnauba wax has silicone added to it. I was having so much trouble finding a product that doesn't have silicone, that I called Griot's and asked for the wax that does not have silicone. The lady there told me they sell no silicone-free waxes; every wax they sell has silicone in it "for the water repellancy"--I guess that's for the Boxter only!

 

[Canooh]

In some general research, it appears nearly every wax-type product contains silicone. Even marine waxes seem to have it. I found American made synthetic compounds, but the few natural non-silicone wax products I could find seem to come out of Britain. I ordered this one:
https://supernaturalcarcare.com/pro...nauba-glaze-500ml?_pos=1&_sid=45f600b2d&_ss=r. They claim it is the safest wax to have in a body shop (referring to the adhesion issue @MGC and @Dan Lindberg thankfully helped me avoid).

 

[Todd F]

Was this stuff used a hundred years ago? Not saying things don't improve but if basic principals are followed, solid filler / good paint, that have preserved these canoes for 100 plus years, are we striving for "perfection" when "damn good" is staring us in the face?

I love this website!

 

[Canooh]

Point taken, @Todd F. It appeared many believe some of the preservation and protective efforts I inquired about in this thread (full over-ribs as sisters/splints to broken ribs) would be overboard. Personally, I don't think a little wax falls into that category, but I understand many/most don't use wax at all and doing so might reasonably be considered too much.

I've received really good advice here that has helped me begin to understand these wood and canvas canoes and stay in bounds with my expectations and plans regarding my first, so I wholeheartedly agree this is a great web community and I am appreciative of it.

 

[Todd F]

I continue to get great advice as well. My comment is something I ask myself regularly! Look forward to seeing your work.

 

[Canooh]

I took my maiden voyage (just a few miles of paddling, all within little more than a mile of the launch point) in this 20-footer. It was my first time in a wood and canvas canoe. It rolled even more than I expected, when entering it from the ground. It felt like trying to balance on a ball...on ice. It both rolled (seemingly without any side-catch) and it wanted to skate away from me across the top of the river. I didn't have anyone holding the canoe as I entered it. When I finally realized I couldn't very well ease into it and simply hopped in, I fully expected to swamp it--all just trying to enter the thing. But, within a couple of minutes, I got my balance and was righted and the rolly feeling faded. My wife had the same initial insecure balance, even though she entered fourth, after our children. Obviously, it was a great deal more stable with each person's weight added--you can tell it was made to haul significant weight and welcomed it.

I thought this behemoth would be very tough to get moving. I envisioned breaking the blade on my wide paddle, when trying to brutely pull a full stroke to quickly get moving from a standstill, but she made easy work of it and glided along. She moved gracefully, really, especially for her size. It seemed much easier to move this long canoe than the newer, flatter (and much shorter) canoes I am used to. Admittedly, the last canoe I was in earlier this summer was a 169" poly Old Town laden with camping supplies, so the difference may be somewhat exaggerated. However, one can still tell an apples to apples comparison of maneuverability is easily won by the older lady. I can see these wood and canvas beauties are favored for more than just their looks!

Now, I just need to touch up her paint and maybe wax her down and I think I'll be set for a while.