Fixing oil canning


My royalex canoe oil-cans in the center (16’ Dagger reflection royalex). Do anybody have tips to fix it.

I thought of any kind of wooden rib…

Foam Block
The simplest solution I’ve seen was to simply stuff a large foam block between the bottom of the hull and the center thwart. The foam block simply appears as a column of reinforcement. It seemed to work in a Sundowner 17 that was used to race on moving rivers.

You can either steam bend or laminate a rib to fit. If you have wood gunnel on the thing you can simply snap it in under the gunnels. I have had a rib in my old mad river explorer for years and am about to add two more. If you steam bend I would recommend northen white cedar. If you laminate, western red cedar ripped to 1/16" strips to make the bend. You may still have to soak these to make the bend. In that case bend them into place and let them dry there. Then take them out and laminate them.

The simplest method I’ve used …
… for longitudinal support (I don’t think just one lateral rib in the center is enough) for a Wenonah Adirondack is an old 215 cm cross-country ski that has a lot of camber. I post down to it from an extra strong thwart (a 1X4 with a center lamination of another short 1X4 section) which is temporarily stuck underneath the gunwales near the yoke (the yoke isn’t stiff enough to post down from). The cambered ski holds the belly in it’s optimal arch and thus keeps it from flattening or becoming concave relative to the water below. I also post down from the stern thwart and bow seat to the ends of the ski. This arrangement is just a pressure fit configuration that presses in and pops out conveniently for transport. Rubber anti-skid “fabric” under the ski helps keep it from moving once under tension. The 3/4 inch dowel posts and ski only weigh a pound or two total and are mostly out of the way. The increased performance of the canoe with it’s optimal arch supported makes this jury-rigged keelson worth adding to any wide-bodied Royalex canoe that has a belly which flexes upwards when pressured by tandem paddlers sitting far apart.