Help with reining in rails on a Chestnut Prospector

[Howie]

I've recently started restoring a 1972 Chestnut Prospector 'Fort', and I've run into a problem that I'd like some thoughts as to how to solve.

The canoe's inner rails are 'bowed out' a little in the front. This is because the canoe has no thwart close behind the front seat. The canoe does have two thwarts: one placed in the center and another a little ahead of the rear seat, but apparently the center thwart is too far away to prevent the movement. Also, the front seat is lowered from the rails by spacers, so it can't hold the rails in place either. Consequently the rails in this area are bulging out by over an inch. This causes the seat spacers to splay inwards from the rails down to the seat, and I fear that this will do damage to the rails someday.



I'm looking for ideas to solve this.
1) I could simply add a third thwart behind the front seat. But this would change the 'look' of the Prospector and it would get in the way of anyone wanting to paddle the canoe sitting 'backwards' in the front seat. I could also use wing-nuts to secure the thwart and thus make it easily removable when paddling backward, but the canoe would still look different.
2) I could modify the existing seat, or make a new seat, to accommodate the wider distance between the rails.
3) Or I could add some wood to the sides of the seat that would allow me to fasten the seat to the ribs instead of (or in addition to) the rails. Thus the seat acts as a thwart. The front seat in my Rushton is held in place in this way. The seat spans 3 ribs so they ought to supply enough support. And the canvas would cover the screw heads so water leaks wouldn't be a concern.

Seems to me option 3 is the best as it'll correct the problem, be unobtrusive, and maintain the classic Chestnut 'look' and functionality.

Thoughts?

 

[Gil Cramer]

I would likely leave it as it is.

 

[Dan Miller]

I agree with Gil. It’s the Chestnut Charm.

 

[Howie]

Aw gee... don't think I can ignore this - it just passes the problem to someone else down the road. They wouldn't be able to sit in the front seat without it swinging left & right, tearing the seat apart, and eventually damaging the rails. Better to fix it now. What I didn't mention is that the front seat is all torn up already. Sure, they are flimsy, but as you say that's the Chestnut Charm.

Well, first things first. I've already epoxied the broken scarf cuts (original) in the rails. Next I'll add ring nails to attach the ribs to the rails. Many were never attached to the rails at all, and those that were were with steel (rusted) nails. Then replace 3 or 4 busted ribs. Time enough to give the seat problem more thought...

 

[Howie]

What I finally did was measure the width of the canoe at the rear thwart and compare that to the equivalent spot at the front. The distance is just about equal. That's as it should be, but surprising as there's no thwart to stop it from splaying out. But with that being the case I can't modify the existing seats to pull in the rails - it'd distort the canoe.

So I'm thinking my seats were made to the wrong size - like maybe they were meant for a shorter canoe? Can someone measure their seats on a 16' Prospector? Here's my measurements for the two outer slats on my seats: Front seat measures 28-1/2" & 26"; Rear seat measures 20-3/8 & 25-1/4"

 

[MGC]

I think you are on to something. If you pull the boat in too much it will end up with a pucker in the lines.
Before your seat revelation I was thinking about a 4th option for you to pull things together.
I don't recall which of the Huron folks was known for inside rail attached seat hangers, Bastien? If I were trying to pull things in and deal with the lowered seat I would be very tempted to do it that way. A solid piece of wood will provide a much more robust attachment than relying on the bolts to do the job.
I think you once restored a boat that was set up like that? Here's an image I found on another thread that shows that attachment method. Look at image three posted by Treewater. http://forums.wcha.org/index.php?threads/bastien-brothers.10186/#post-72983

 

[Howie]

Right Mike... I had thought of that. Both the Bastien and Langford I restored had a one-piece-dropdown-log for seat spacers. I think they're actually a good idea. But not 'accurate' for this canoe.

 

[Dave Osborn]

I’ll be doing a Prospector soon and will deal with the same issue. No thwart behind the bow seat….
I once did an Ogilvy that had a severe problem in this regard. Partly, I think, because of closely spaced 3/8” ribs wanting to spread. If my recollection is right, I added length to the seat stiles and hung the seat below the gunwales rather than trying to pull the gunwales in.

 

[MGC]

So now it's my turn to deal with this Chestnut Charm.
Since I brought this boat home the pucker in the middle has been driving me literally nuts. Instead of a nice contiguous inside and outside curve bow to stern the boat looks like it's pulled in at the middle. Today I finally had enough. I removed the center thwart. Lo and behold, The canoe now looks about right. It turns out that the thwart was cut too short and in order for it to be installed, they pulled the rails together to make it fit. It looks to be about 1 1/2 inches too short.
My options are to lengthen the thwart, make a new one or put the bugger back the way it was.... and that is definitely not an option.
The thwart appears to be maple. It is original.
When they installed this thing, they knocked a corner off one end by accident when they jammed the bolts through the rails. The fix, they varnished over it. The other surprise is that the back of the thwart is raw wood. It has never been varnished. Aye yai yai. I guess I am going to remove everything.

 

[Dave Osborn]

I’ve lengthened thwarts to solve this using a step joint and a similar wood grain. Most of it ends up under the inwale and it isn’t seen.

 

[Howie]

Mike: I've added length to thwarts occasionally. Sometimes the thwart was too short as in your case, sometimes the wood at the end is rotted, and sometimes the bolt hole at the end has pulled out. All I do is cut the end of the thwart off at 45deg - leaving the longer section on the upper side of the thwart - and epoxying on a appropriately sized length of wood with one end also cut at 45deg.

Yup. As much as we respect those old w/c canoe workers they did make goofs. You know my Rushton Indian had the thwarts in the wrong positions that gave the canoe a goofy Coke bottle profile. And the Shell Lake I'm working on had carry thwarts that were either made too long or located too close to the decks as they caused 2 cracked inner rails and caused each rail to pull away about 3/8" from the front of the deck plus cracked one of the decks down the middle.

BTW... my per peeve with every single canoe I've restored is that the manufacturers only varnished the wood that was visible. I've rarely seen a deck with the underside varnished, never seen the inner side of the outer rails varnished, a have sometimes seen just the tops of the seats & thwarts varnished.

 

[MGC]

I’ve lengthened thwarts to solve this using a step joint and a similar wood grain. Most of it ends up under the inwale and it isn’t seen.

I agree with that approach. It's pretty much the same repair I do when I repair blown out holes or rotten ends on a thwart. I was digging around in my scrap boxes for some wood last night. I usually put a step on the thwart with my dado blade and then match up to the step. And...it will be almost entirely under the rails.

 

[Dave Osborn]

Lots of glue surface with the step joint and the bolt can go through both the original thwart wood and the added piece.

 

[Rollin Thurlow]

I would vote for adding the extra thwart just behind the seat. It will be the most effective and strongest solution to the problem. As for paddling solo from the bow seat, the thwart is not really any problem at all. You would think it would be but its not. I paddle my Traveler from that position all the time and the seat is 2" lower than the thwart and I don't even notice the thwart either sitting in the seat or dropping to my knees and getting back up, the thwart is never in the way or even a consideration.