Attach Seat Mount Bracket? --Canoe

I want to attach seats to the side of the Royalex Chipewan rather than hang the seats from the gunwales. I know this is done for many canoes, but I don’t know how common for royalex.

Questions: What to use for a bracket?

How to attach the bracket to the hull

Candidates for the bracket:

  1. wood, cedar for lightness. Seal with epoxy. It’ll get drilled to accept seat-retaining bolt, so the hole will need to be somehow sealed, too.
  2. aluminum angle material
  3. fiberglass angle (what I wanted, but have not found)

    Candidates for attaching to the hull:
  4. epoxy, with or w/o some fiberglass fabric
  5. silicone caulk (I once used some to attach an aluminum shower frame to a tile wall, and when I later removed the frame, the caulk was so tight it ripped off the glazed surface of the tile.) The reason to use silicone is its flexibility.
  6. mechanical attachments through the hull (pop rivet, wire-stitch or bolt)

    Or, feel free to recommend something you think will work.


    Chip Walsh, Gambrills, MD

Look at Mohawk Canoes. They may sell this ready made. To improvise:

4" to 5" piece of aluminum in with and then how deep to fix a flange at the bottom to shape an L for the seat. The lower in the boat the better the center of gravity but the trade off is if you sit on knees while canoing getting your feet out from under that seat is the trade off. Slip the aluminum under the inside gunnel and drill hole to accept a screw and compression nut to attach. Look at the pop rivets location and maybe can change them out. You can also put and angle on the aluminum to set the seat at the angle to fit the butt better. Some solo boats have this feature

Just wondering why you wish to avoid hanging the seats from the gunnels.

Each seat would be four holes in the thick gunnels vs. eight holes in the thin hull.

BTW, I’ve no experience with hull-mounted seats in royalex, but one of the most secure methods I’ve seen used in composite hulls are sections of aluminum angle stock mounted with 4 rivets (altho I think 4 small stainless bolts with lock nuts would work just as well or better with little weight gain) The seats simply bolted to the mounted angle stock.

I can’t imagine how silicone caulk could be expected to hold the vertical loads a seat would encounter…

More info
To answer Coyoteequip, I’m looking for the seat to provide rigidity in place of a thwart. I plan to drop and slope the seat 2-3" below the gunwales which will leave 8" of space under the seat, on the theory I can get my feet under. If I hang the seats from the inwale, there will be play among inwale, hangers, and seat, and I don’t think I’ll get much rigidity. I think I’ll get more stiffness from side mounting to the hull.

I’d like to use aluminum angle. My concern is that there will be different thermal expansion properties between the aluminum and the royalex, so that glue won’t hold. That’s why I am thinking of silicone caulk, because of the flexibility. I’d rather not drill the hull for mechanical fastners. And as mentioned, the royalex is relatively thin and weak. Plus this hull is so old, it’s all a crap shoot anyway.

Eric, I thought about making my own brackets from glass and resin. I figured there’d be less difference in the expansion factors if I stick to glass and resin, but that is just a guess on my part. I do know that vinyl has an above average expansion factor. Ever stand beside a wall sided with vinyl when the sun hits it? It makes a lot of noise as the pieces expand and slide. When installing it, care must be taken to not tightly nail anything, else you get “waves” in the siding. And isn’t vinyl one of the layers of royalex?

Maybe I’ll use hangers plus side mount to aluminum channel glued to the hull, and I think I will try the caulk for the aluminum to royalex bond. If the side hangers don’t hold, I at least will still be sitting. If the hull isn’t stiff enough, I can add a thwart.

Thanks for sharing your thoughts,


another 2c
If you don’t wish to drill for fasteners, I don’t think your silicone is gonna hold a seat. Combined with drops you may have a chance…?

If it was me, I’d use seat drops from the gunnels and give it a test paddle - if the hull wasn’t as rigid as I wanted I’d add a thwart. But then again, I like thwarts.

Let us know how your silicone attachment holds up if you go that route. I’d be interested in hearing how that plays out.

Good luck.