Reinforcing a fiberglass canoe

Hi Forum,
I need some advice. My wife and I recently picked up a very used 1994 fiberglass Mad River Malecite. This is the first canoe I have ever owned. I read lots of reviews about different boats and was very excited to find a used Malecite in fair condition. I tested the craft by myself on a lake where the boat was stored. The boat tracked well and glided much better than any of the cheap canoes I have rented in the past. I was very excited with my find until I got the boat home and tried to go out for a paddle with my wife. I am a bigger guy and with both of us in the boat we have about 380lbs in the canoe. I noticed that the bottom of the hull at my end (the bow) was deflecting a bit. My excitement with the craft has know made me wonder if I made a good used purchase. I tested the boat again today and used some tie down straps to help add some tension to the thwart. This helped significantly but did not remove the issue entirely. I am thinking I will need to install some foam ribs with fiberglass encasement on the inside of the hull to remove this issue entirely or learn to ignore the oil canning along the bottom of the boat. I will say the boat still tracks well and we still had a good outing, but I would love to remove the issue if possible. Any advice or suggestions are most appreciated.

I’m not an expert on the subject but I think some movement is expected in a light weight canoe like that. I have a poly 3 layer canoe and had a similar problem (not sure it was a problem) but the flat bottom had some bounce to it in the water under my feet.

I took a foam block and fit it tight under the seat. I actually rigged up a cross brace under the gunwale and some blocks and a wedge so I could flex the bottom down maybe a half inch and then I slipped the foam block in so it was under a little pressure. It holds the hull in that area and it puts some of my weight on the hull and some on the gunwale. I also added a couple thwarts I made from old aluminum tent poles I cut to length and flattened in a vice. One is right behind the seat. I have a seatback seat I put in and I don’t know how much the thwart adds but it can’t hurt. Here is a photo of what I did. :canoe:

Thanks bud16415,
I did kneel over the deflection area and a little pressure certainly does the trick. Perhaps, I just need to bring a rubber mat and my lab next time.

Still thinking it may be worth creating some structural foam ribs and use fiberglass sheets and resin to bind the added structure to the sidewalls and deck. I have seen this done with the Kevlar composite Malecite canoes as part of the factory composition. Seems like my fiberglass model could have benefited from a similar design. Perhaps, it was left out to save weight. Going to this trouble though may be overkill. It is certainly not a cheap adjustment. The glass mat, structural foam, resins and binding additives can be pricy and potentially very messy experiment. As such, I am interested to know if others have addressed oil canning in a similar fashion on fiberglass canoes or if I should just expect this deflection and not worry about it.

I know it doesn’t show up great in the photo but the hull bounces a bit where my ore handle is in this photo.

Yes in my case I was converting the tandem to a solo so that put my new seat location right about where you are pointing.

Ribs like you mentioned would be some work for sure. If you wanted to try it out without messing up your boat I would make a cardboard template of the hull cross section where you think it should be all the way up to the bottom side of the gunwale and cut one out of plywood. Then put two ears on both sides that could be attached to the gunwale. You could hold it on with some little C-clamps to see if it helped.

My guess is you are used to some tough heavy rentals and some of this is normal.

My poly boat was actually taking on a hog to the hull and also I move it with a dolly at that same spot and it was flexing when I would roll it down a path to a ramp. That and like you I didn’t like the feel of it on my feet. :canoe:

Based on the MR Independence of similar vintage that lives here, that flex in the 'glass hulls seems to be normal. I did add some glass tape & epoxy on at the chine to stiffen the hull some and it did help. I do treat the Indy a bit more gently than my other canoes If I think that I’ll be bumping rocks or logs I’ll the the Tuff-weave Rendezvous. With the center rib construction that canoe will handle a lot.

Right off-hand, I think that you shouldn’t worry about it.

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Thank you bud16415 and rival51! I really appreciate the feedback and suggestions.


It is a honeycomb foam. Cut pieces a couple of inches wide, glue down with epoxy and put fiberglass cloth over it and epoxy that down.

Thanks CraigF,
I was looking at the Divinycell 5 lb. Density foams. These seemed like a good option because they can be thermoformed (heated and formed to match the hull shape). I think if I chamfer the edges I could epoxy them to my fiberglass frame and use some overlapping strips of fiberglass mat with resin to hold it all in place. I know Mad River did this with the ultralight Malecite design and I think I would try to replicate their ultralight design as much as possible (probably five ribs and maybe a floor plate). Photo below is taken from the Mad River website and shows the ultralight Kevlar version with the foam rib design. I am good with construction projects but fiberglass work would be new to me. I am just trying to decide if it is worth time and cost. I do like the canoe and want to make sure we get to experience the best it has to offer. I don’t mind putting in a little sweat and elbow grease if I can get to that goal. I thought for sure someone would have attempted something like this already and I could benefit from their experience. Thanks again!


There will be some flexing of the hull, if there isn’t any the hull may crack. Look up the youtube channel Boat Works Today for great videos on repairing fiberglass boats.

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