Doing tips a little different

[mmmalmberg]

I'm trying a little something, really a different version I think of the "sub-deck" concept but in brass instead of wood.

My objective is to improve on (and eliminate) the brads from the inwale tips into the stem tip. Having seen the amount of rot around those tips at both ends of my OTCA, I feel that any perforations of the wood right at the tips is a big invitation for rot. I'm going to be sealing all of the surfaces that meet at the tips with penetrating epoxy, and am using these brass parts I'm making to move any holes further away from the tip while strengthening the joint overall.

I know I'm asking for it but sharing here nonetheless

Attachments will be probably a machine screw a couple inches down the stem, possibly making the last stem band screw a machine screw extending down into the brass piece and possibly a wood screw further back from the back of the brass piece up into the deck. The option is there to put screws into the inwales but I'm not sure it's needed or wanted.

My one concern is the brass tabs on the outside of the inwales, being in the way of the planking or outwales. In which case I could grind these tabs down with a taper toward the front.

Weight is 3/4 lb for both.

Ok, let me have it

 

[Dave Osborn]

Overkill, but nicely done.

 

[Dan Lindberg]

Agreed, I like it.

 

[MGC]

I once had a customer describe one of the machines I designed as a goat with 5 legs.....
What I'm curious about is what ties the cant rib in?

 

[mmmalmberg]

I once had a customer describe one of the machines I designed as a goat with 5 legs.....
What I'm curious about is what ties the cant rib in?

Only planking as far as I can tell, ?

 

[MGC]

Only planking as far as I can tell, ?

It's been quite a long time since I worked on an Old Town but all of the canoes I've worked on recently or built had the cant ribs tied in to the inside rails. The only Old Town I currently have here is a double gunwale (not the same construction) so I went out and looked at my 1920's Carleton. I presume that construction must be very similar to an OT (they were often built as OT and tagged Carleton). The front cant ribs are very thinned down but definitely attached to the rails as I'm assuming yours probably should be. I'm far from an expert so hopefully someone else that has worked on OT"s can chime in.
The idea for the brass adapter is pretty interesting. I'm wondering if the side bars should be narrower so that that they could be inletted into the rails? That would keep them from being visible between the cant ribs.

 

[Howie]

That's a wonderful machining job.

If I remember correctly, someone posted a thread a few years ago where he achieved the same thing - ie, locking the stem to the deck - by simply epoxying a shaped chunk of wood to both the deck & stem. I asked whether he was worried about some restorer a few years hence swearing up a storm when finding a deck bring epoxied to the stem. His reply was that if someone had to make repairs to this area it would likely involve wood rot, in which case the epoxied block would be a moot problem. He wasn't wrong...

 

[mmmalmberg]

Regarding the cant ribs, mine show no sign of having ever been attached to anything at the top. They are just bluntly tapered to squeeze in under the inwale.

Re. the "sub-deck" yes I've seen the thread about that and this I think provides similar functionality but nothing gets glued to anything so it all comes apart with two or three screws. Actually I glued some ash pads today to the underside of the deck points to thicken that area up to the depth of the inwales so that the brass pieces will have something to snug up against.

I know that the way it's been done for the past 150 years has worked pretty well. My thinking is, there are a handful of people today who are rebuilding old wood-canvas canoes. I'm sure this canoe will make it at least into my grandkids' hands (if I ever have any) since my kids are grown already and of age for such. So I'm wondering, in my great-grandkids' generation, will there be anyone at all left who would know what to do with an old wood-canvas canoe when it is time for wood repairs, new canvas, etc. Possibly not, and so I'm just trying to give this thing the longest life I can, within reason. Those brackets took me a morning to make, no big deal. Stuck a piece of paper in where they were going to fit and traced the shape with a pencil, drew in the final shape by eye, cut it on my bandsaw and silver-soldered the tabs on. Actually bending the angle on the first one I did took a long time, just couldn't get it quite right without a lot of back and forth of where that bend needed to be. Lucked out on the second one, first try. Granted I spent some good time looking at it and thinking about it for a few weeks before I did anything

I did think about making the tabs closer and letting them into the inwales but I didn't want my little project to weaken the inwales. Today I ground them down so that at the front edge they're about 1/16" thick. I guess I'll see when I'm putting planking back on whether I need to do more, or something different... And then we can all check back in about 70 years and see if it worked

 

[Michael Grace]

The way your cant ribs end is not at all uncommon. It's regularly seenin older canoes, and it's the norm in the modern Old Town Molitor where cant ribs rise to meet the highly recurved stem. Distinct but related, some early makers like White and Gerrish supported the planking ends very lightly. The attached image shows a single thinner thinner cant rib over the last large span of planking in an E.M. White. These approaches seem to have worked, even if they aren't what my sometimes over-engineering mind would have come up with.

About the brackets, reinventing the wheel is fine... As is often said here "It's your canoe; do with it what you want." I believe in that addage, but where does it stop? Shore up the gunwale/stem joint, "fix" the cant rib issue, remove the keel and sponsons, add half ribs, cover with dacron and epoxy... Nothing disparaging is implied or intended here. The approach is up to the owner/restorer, and the approach to repair or restoration may be dictated by intended use. Some may wish to keep things as original as possible and historically accurate; others may wish to try out new solutions. In any case, when major repairs are needed (such as in canoes with rotten ends) something must be done and short of replacing entire stems, gunwales and decks, there's always going to be obvious modification.

 

[mmmalmberg]

I'm stopping at the brackets! Shoring up the tips is my only goal for improvement as it seems like the most common long-term failure point as far as I can tell. Thanks

 

[Dave Osborn]

Hopefully the brass does not trap moisture under the deck and cause the issues that you were trying to prevent.

 

[mmmalmberg]

Hopefully the brass does not trap moisture under the deck and cause the issues that you were trying to prevent.

Yes I hope so too. The tips are inherently full of moisture traps though. I'm sealing every surface in the tips with penetrating epoxy followed by a coat of varnish so that should help. Eliminating penetrations in the tips will also help. I may have an option of spacing the brass out from the deck with a washer, as well.

What I haven't looked at yet is the outwale attachment at the tips...

 

[Gil Cramer]

Interesting method of preserving tips. Tips are a perfect storm for rot; enclosed on three sides with no way for moisture to escape. Thompson Brothers canoes are much better at allowing moisture to escape in the stem, and have less tip rot. For most canoes, the absolute best way to eliminate rot in the tips is to never turn the canoe upside down.

 

[mmmalmberg]

Interesting method of preserving tips. Tips are a perfect storm for rot; enclosed on three sides with no way for moisture to escape. Thompson Brothers canoes are much better at allowing moisture to escape in the stem, and have less tip rot. For most canoes, the absolute best way to eliminate rot in the tips is to never turn the canoe upside down.

I'll have to find images of the Thompson tip treatment. I'd thought of cutting the tip of the deck back about 1/4" under the stem band to allow some ventilation.

 

[mmmalmberg]

View attachment 45744 View attachment 45745
Gil makes the most important observation when he points out the importance of proper storage.
Case in point, this is a perfect 114 year old deck. The other deck is just as solid. As a double gunwale boat the rail and deck construction and fits are even tighter than most the other hulls. Storage...….

Agree 100% re. storage. I can't control how my grandkids and their kids (or whoever) treats or stores this thing. If it lasts another 70 years, somewhere in that timeframe it's likely to have a few years of poor treatment. But one never knows...

 

[martin ferwerda]

This is basically how Thompson did the tips, the top of the stem is butted against the end of the inwales, so the stem tip is exposed. I believe Thompson used a nail or two in the joint, I prefer a stainless screw.

 

[mmmalmberg]

This is basically how Thompson did the tips, the top of the stem is butted against the end of the inwales, so the stem tip is exposed. I believe Thompson used a nail or two in the joint, I prefer a stainless screw.

Got it. Yeah the ends of the stems are able to dry. Makes sense - thanks

 

[Rollin Thurlow]

The brass stem-rail- deck jig may be a bit of overkill but it does make for an interesting solution. Just to make it slightly more difficult but maybe a bit better how about this suggestion. Bring the heavy rail wings in line with the inside rails and mortise or notch the rails to receive the wings, then the wings wont interfere with the ribs or where the planking wants to rest. Also one wing could be countersunk for a #10 flat head machine screw and the one on the other side taped with threads to receive the bolt. This way you can bolt the inside rails and tip of the deck together. Once everything is bedded and bolted together it should last for a good long time!

 

[mmmalmberg]

Hi Rollin! I did think about letting the "wings" into the inwales but was not wanting to weaken the inwales. In hindsight, I think it might be a nicer way. Since the inwales are screwed to the deck the decreased strength might not matter. I did thin the tabs a bit to fit under the planking. I like the idea of a screw going between the two and may look at that. It will make the whole thing sturdier.

Here's the tail end together... The end screw of the stem band will screw into the brass, probably right where I scrawled my name but hopefully further back. The stainless screw you see will be replaced probably with a silicon bronze round head countersunk into the stem.

 

[mmmalmberg]

Came across this "before" picture of the tips which explains why I wanted to explore eliminating perforations of the various tip bits with little nails and screws...