Replacing seats, should I add thwarts?

Howdy All,
I picked up an oldtown guide, the BIG one, as a good family boat till my kid is ready for the skinny sawyer.
I want to upgrade the seats from the hard plastic seats to “traditional canoe seats” you know wood and mounted with hangers from the gunwales.
The plastic seats however function like thwarts, thinking it would be prudent to add thwarsts too to make up for the lost lateral stability.

But wondering has anyone had success with just the center thwart with these boats with traditional seats?

My 16’ old Town has two seats and a single thwart, and is 45 years old.

Are you lowering the seats?

I wasn’t going to lower them, the canoe is so stable I’m fine sitting up high for most water and kneeling the rest.

Then they are basically a pair of thwarts each

The seating surface on the molded polyethylene seats is significantly below gunwale level, so if you replace them with wood framed seats and want to sit at the same height you will need to suspend the seats from some type of hanger. A one-piece truss type hanger will offer a bit more rigidity than individual dowel hangers but either way you will probably give up a little rigidity because the one piece molded seats do provide more bracing than a wood frame seat suspended from the inwales by machine screws.

The majority of 16 foot tandem canoes made out of Royalex or three-layer rotomolded PE have an added thwart besides the seats and center yoke but a few do not. My suggestion would be to go ahead and swap the seats and try paddling the canoe. If it seems to have more flex than before you can go ahead and add a thwart midway between the center yoke and the stern seat.

Over the years I have added a lot of thwarts to used canoes. For a tandem tripping canoe 3 thwarts are best. They provide rigidity to the hull. Not only that but they give you places to secure your gear in the boat. When you swamp a canoe in moving water, you will be really glad that you have 3 thwarts.

In the old days I used to make them from white ash. Now it is easy to buy thwarts that match your boat pretty well. I have never liked the aluminum thwarts in canoes like Wenonahs.

Replacing the seats and thwarts in a canoe with ash ones is easy and a very rewarding project. You can put everything where you want it and it really helps the look of a canoe.

Great info, thanks. I did notice that all the old town canoes on their website with hanging seat set-ups had that second thwart between the yoke and stern seat.

I was looking at contoured wooden seats as an option, but thinking the drop there would be less than the 3" in the plastic molded seats on the boat currently, the truss hanger seems like a solid plan.

I agree, the wooden look is clean and classic. And I love tie downs and jamming my bags under thwarts for expedition paddles.

I had read an article about how most canoes are under-thwarted to reduce weight. Definitely leaning towards adding thwarts regardless of the seat setup.

You can get an ash thwart from either Essex Industries Thwarts or Ed’s Canoe Standard Thwart for 14-15$. Both of them are also a good source for wood frame seats and seat hangers.

You will need some longish stainless steel machine screws to hang seats. You want #10 size in either 24 threads per inch (10x24) or 32 tpi (10x32) with matching stainless nuts with nylon locking inserts. Machine screws for mounting thwarts under the gunwales only need to be about 2 1/2 inches long and can usually be found at the local hardware store. But the machine screws for hanging seats need to be considerably longer since they need to go through approx. 1" of inwale, 3/4-1" of seat frame, plus whatever the depth of your hangers happens to be, plus another 3/8" or so for the nut. Stainless machine screws more than 4" in length can be hard to find locally at times so you might want to order a couple of sets of screws and nuts when you order the seats and hangers. Ed’s Canoe has them.

Thanks for the tips and links, super helpful.
My boat is going to be so thwarty, I’m going to start calling it the “thwart hog”