Oil Canning

Several people in another thread have suggested that the Wenonah Spirit II fits my family’s canoe needs. While researching that model, I’ve read the Product Reviews on this site. Several mention a problem with “oil canning.” What is this? Remember, I’m a newbie.

Think of the old…
3- in- one oil cans.

You push the sides in to get the oil to come out and the can indents as you do it, and then when you release the pressure the indent pops out.

That is “Oil canning”.

If you strap a poly or cheaply made canoe or kayak down to a car too tight or too long it is liable to oil can.

Most of the time the indent will pop out when you release the straps.



oil can

Oil canning is when water pressure does what your thumb used to do with the old fashioned oil cans.

It hurts performance
Now that you have the mechanics, nothing cuts through water better than a rigid form.

When on the water
oil canning is when the hull of your canoe flexes a little bit as water moves under the hull. I have an Old Town Pack (royalex) and it does a bit of oil canning especially in rougher water. It does not permanently damage the canoe as it flexes back. As stated above it does impact performance slightly however since you are planning to use a cnaoe for family recreation and not racing I doubt if you will notice any difference.

lots of definitions…
…I agree that if your boat dents & then the dent readily pops out, it is similar to the action of using an oil can, but still call these (temporary) dents.

My def. of oil canning is a section of hull that alternately dips in and out; a permanently rippled or wavey area. It is not caused by water or strap-down pressure. I’ve seen this in new boats on the showroom floor & believe it is caused either in the manufacturing process or afterwards by heat and improper storage. The culprit is altered linearity.

If you take a flat piece of plastic or vinyl (a section of house siding, for example) & allow it to sag (lengthwise or widthwise) in the sun for a few days, when you attempt to straighten it it will “oilcan.” The effect is often permanent unless the piece is allowed to sag in the opposite direction before re-straightening.

Dents usually go away; true oilcanning is much harder to correct.

I’ll say!
I’ve never before seen so many definitions of “oil canning.”

This may be a record.

Yeah, this has …
been a subject here before with lots of different definitions. Our Spirit II does this somewhat. You can see the inside bottom of the canoe rise and fall while traveling through the water. The hull always goes back to it’s original shape when we take her out of the water. Considering the barges we’ve rented in the past, the Spirit II (for us) is a winner. Much faster and turns much better. But then again, I haven’t paddled long either so…take it with a grain of salt.

hull bottom flexing while paddling
is the classic definition of oil-canning. Distortions in the hull from heat or tie-down ropes and straps are not oil canning. That is hull distortion or warping. If a hull is permanently sagged it is hogged, or hogbacked. Oil canning is not a static state, it is a dynamic state, it is unintended and undesired movement of the hull bottom while paddling. It does hurt performance, but is not significant at recreational speeds.

Large, wide, and relatively flat hull bottoms in Royalex and Polyethylene hulls are the most likely to exhibit this movement. The manufacturer must choose whether to make the bottom so thick that it stays rigid under all conditions or except a degree of flex and oilcanning to maintain a lighter hull. All canoes are a compromise.



– Last Updated: Jan-04-06 7:09 PM EST –

After going around and around with this topic in the past...
I vote for this explanation...

One Solution…
Our FG Oneida 18 oilcans amidships when there’s just paddlers aboard - that is, the bottom tends to bulge inward as you move thru the water. It’s not a serious problem, but it’s easily corrected if it bothers you.

Lay a flexible piece of board or ply 12"-18" long and 4" wide lengthways along the bottom, centered under the centre thwart. Cut a piece of 3/4" x 1.5" wood to fit between the bottom and the thwart; notch the top end of the stick to fit under the thwart.

The stick is positioned by sliding it in under the thwart from the side on a shallow angle - it should just fit snugly at 90 degrees when given a final tap with a hand. This braces the centre section very nicely, can be done in minutes, and costs nothing.

Try a web search
But allow yourself plenty of time for all the uses of the term “oil canning”.

IMHO it’s the flexing of the hull due to water pressure.

Hull stiffeners
The Seda Scout fiberglass layups had a wooden prop from the yoke to the center rib to keep the hull from flexing. Wenonah for years offered a “whitewater” version of some of their hulls using a center rib construction with shock absorbers mounted from the aluminum thwarts down to the center rib. This kept the hull from flexing in normal paddling, but would let it flex over rocks and other whitewater obstacles. Their shocks could be used in other boats my making your own anchor pads in the hull bottom.


Oil comes in plastic bottles, not cans.

Oil Can…

I’ll bet that is worth…
a few bucks!

I have one the exact same, that I keep cutting oil in for when I am drilling, and I have had several “antique” buffs beg me to stop using it.



Think EBAY, Jack
You wouldn’t believe what some of the old stuff I found in drawers sold for…

I’ve been trading my old toys for new toys…

JackL’s Age

– Last Updated: Jan-07-06 8:44 AM EST –

Jackl showed his true age when defining oil canning as when pressing on the side of a 3 in 1 can of oil. Those were rectangular small home use cans painted yellow, the modern (to him) oil canning.
If truely old, he would have described (like Grayhawks link) black rusty round cans, flat on bottom with a long, soldered and leaking slender oil spout on top. To use, invert, aim, press on flat bottom until it pops inward and makes a "DuWop" sound and oil pops out. Press again for more oil (DuWop, DuWop, DuWop). Hence forever more, "oil canning" and the advent of the DuWop age in the music he grew up with.

Oil before cans
Come on Canunut, Jack thinks the oil can is new stuff, he got his first oil at the wharf in wooden barrels from the sperm whalers themselves.

Definitely the true oil can is the one described with the long slender spout to reach the oil cups on the bearing oilers. And its sound is a piece of Americana and our youth, like the screen door slamming, and the sound of an axe splitting kindling wood in the morning. I think Jack’s reference to the 3-in-1 can was made for the younger folk who can only think of oil in plastic bottles and don’t remember opening quart oil cans with an oil spout to put oil into a car engine.

Is the oil spout another antique for E-Bay profit?

Not old, but experienced,


He, he !
Would you believe that I still have a unopened round can (I think a gallon) of “Jenny” Motor Oil from about the forties in Boston.

Also a unopened can of sandsoap from about the same.

I just can’t get myself to chuck that junk out.

Sorry Canunut, I did use those cans when you were just knee high to a grasshopper. Your showing your age too!