Improper Storing of Heavy poly canoes

I have seen so many Crosslink 3 Old town canoes, Triple Tough Mad River canoes and many lesser brands ALL made from heavy multi-layer that are severely buckled/warped/oil-canned along the keel area. I am certain that these type canoes should NOT be stored upside down on its gunwales like all other canoes. The wieght of the heavy poly eventually will cause hull warping,…especially when coupled with the suns rays/heat. I bought a 10 yr old Mad River Teton and its hull is VERY straight certainly because the owner stored it upright on a flat sandy spot in the shade. Had to replace the rotten seats and thwart but it was cheap. Just thought I would recommend to new owners of these type canoes to consider better storage options. Anybody else have ideas about this?

I think you are 100% incorrect …
… deforming comes from improper storage in all cases I have seen . One of my canoes is poly and it has always been stored resting on it’s gunnels … it has never been stored inside … it does have sun on it during a period of the day … it does not deform but keeps it’s shape perfectly , just as one would wish it to .

“ALL” the poly canoes I have seen that are laid bottom side down on the ground or other surface , or tilted up against a shed wall on one side … have deformed . Ones that are subjected to a great amount of sunlight in hot Wx are the worst . Even storing a poly canoe on it’s side indoors will allow it deform some .

Those are my reasons for disagreement .

When you read over and over again about the best and proper method to set a canoe for storage , and the advice is to set it level on it’s gunnels a reasonable distance from each end … that should give you some idea this has been well tried and other methods fall short or cause problems … my experience agrees .

We should at least mention that when
poly canoes are paddled over logs, rocks, sandbars, etc., the poly can be stretched, after which it tends to pooch upward.

So, if poly canoes warp however they are stored, and warp under normal paddling stresses, why is poly credited as being so durable as a canoe material? If a canoe will not hold its design shape, its ability to resist punctures or tears is irrelevant.

They ALL end up warped? NOT
If its a Coleman or other single layer poly entry level canoe, I would agree but I know there are some owners of 20 yr old Crosslink 3 Discovery Old Town canoes with straight keel lines. My brother has one. It IS NOT inevitable that they all will warp, owners have some degree of control. The local livery here where I live along with countless other liveries I have visited who have the 3-layer poly canoes ALL stored on there gunwales and they are almost ALL bowed-in. Actually if you do prefer to store the boats upside down, I would bring the cross bars where they rest closer together so that the overhanging wieght on each end will tend to keep some tensile stress (pulling lengthwise) on the hull versus compression stress when the supports are placed far apart. Compression stress coupled with all the weight of the canoe bearing down in the middle accelerates the warping problem.

We haven’t discussed the tendency
of the middle of a canoe to pooch upward just while sitting on the water with two adult paddlers on seats toward the ends. Our old 18.5’ Moore, an 85 pound fiberglass layup, did that until I put keel supports between the three thwarts and the interior longitudinal keel strip. Of course, a FG hull may pooch inward, but will not stretch and take a permanent “set.”

So, maybe we’re blaming the storage arrangement when the stressing force is actually greater when the boat is on the water. I don’t believe that much hull distortion will occur in storage unless accelerated by hot sun.

Yatipope’s brother’s Discovery? Perhaps the boat was not paddled much, and when it was, it often had a center load that held the bottom down.

If I for some insane reason bought a Discovery, I would put minicell pillars between all thwarts and the bottom of the canoe.

coleman yard art
Yeah, I paddle near rich people’s houses quite often. Seems that about a quarter of them have a Coleman canoe, usually upside down on the dock, gunwales flattened out, bottom sagging as if the kids had used it for a trampoline, which come to think of it, is a pretty good use for that boat. I’ve always wondered why multimillionaires buy the cheapest canoe made.

dents vs "oilcanning"
I know there are plenty who disagree with my definition of oilcanning, and also know some use that term to describe pretty much any hull distortion.

What I call an oilcanned area is one that is rippled with alternating dents and raised areas. Maybe “warped” is a more accurate term.

Anyway, this happens to many PVC variations, most often due to expansion/contraction cycles, hence more often caused by heat than by pressure.

I’ve seen cheap rec boats in showrooms with this defect. I was told it can happen in the cooling process just after leaving the mold.

while everyone is entitled to their own
definitions, boat designers and builders refer to oil canning as a flex of the bottom in waves and when underway, rather than a warping of the hull.

Hulls warped upward toward the center of the boat are described as hogged.

Just in case you are talking to a boat designer or builder and they give you a funny look.

yes, I have been recited that…
…definition of a static state, by which any reference to an “oilcanned hull” is inaccurate(because a hull can be “oilcanning,” but not permanently oilcanned). Correct?

In the vinyl siding business, a panel that was nailed too tight on the sunny side of the house gets a permanent warpage referred to as being “oilcanned” to differentiate that from other types of warpage.

That’s why I refer to the pooching up
in the hull of our old Moore as oilcanning. It is not permanent. Fiberglass layups do not stretch. In a poly hull like those of Discovery canoes, oilcanning starts, and permanent hogging may ensue.

That is correct

– Last Updated: Dec-27-10 2:47 PM EST –

Anytime someone refers to a permenantly distorted hull as an example of "oilcanning", I know that this is one more person who's never met an old timer with mechanical experience. Even so, haven't any of these people seen "The Wizard of Oz?"

"Oilcanning" is the process of "acting like an oil can", in reference to how the pumping action of old-time oil cans worked. I'm talking about the kind of can used to squirt oil into precise locations when lubing machinery, not storage cans. The flexing of the can in which oil was purchased or stored is NOT the origin of the word, though the word properly describes what those old containers would do if the oil was poured out without venting, or what what happen to the sides during temperature changes. The bottom of the old-fashioned oil-squirting cans was slightly convex so it would flex with a "snap" when pushed upon. You'd flex the bottom of the can with your thumb, the bottom of the can would say "thunka", and there would be a quick spurt of oil shooting out the nozzle.

Types of warpage.

– Last Updated: Dec-27-10 3:48 PM EST –

What you describe for vinyl siding would be a correct use of the word "oilcanned", and what that bulge does when pressed upon would be "oilcanning". Roofers use the same definition for sheets of material that are pooched up but fastened down around the perimter of the bulge, and that would be another correct use of the word. Note that this is completely different from a sheet of material which simply has a curved or irregular shape for some other reason. If the sheet of material is not anchored in place around the edges of the deformity, it is simply bent, not oilcanned.

I wonder when it will happen to …

– Last Updated: Dec-28-10 11:28 PM EST –

....... our poly canoe ??

I'm not looking forward to it but have always thought the possibility exist . Ours is a 3 layer Old Town linear 16'-9" Expedition (Disco 169 ??) . Personally I think there are differences between it and the Disco but I could be mistaken . Originally purchased a Disco in 06 but that one began to have problems right off the bat ... Oilcanning that increasingly became worse , also had a light twist in the hull .

After exchanging for a new one (a year later) , Bass Pro where we bought it was carrying only the model called Expedition and no more Disco's .

Anyway this Expedition canoe seemed to have a noticably more arched haul and the seats are located in more rearward postion . Have never stored this one inside and it's run an abusive amount of shallow fast current w/haul contacting river bottom ... skinned over uncountable ledge drops and in general I never give any shallow obstical a second thought before charging right through /over it . Think tank and keep on going .

The haul has it's battle scars (nice scratches) but surprisingly they look good to me . I haven't been able to dent it yet though it's had plenty opportunity for that . It's stored on it's gunnels centered up on outlook carriers that have an 8' spread (attached to the post of a barracade fence) . The sun is on it about 1/2 the day .

When the days are real hot on the water in summer , there is an ever so slight oilcanning that might happen in light rapid water , but only sometimes (I've always figured it's because the temps. were up in the 90's) ... but the haul doesn't do that at any other time . It "will" flex just a bit skinning over some rock or submerged trees , but goes right back into light arch afterwards .

If there is a canoe that is suppose to be a flat bottom (I think ??) but has light arch , this is it . If it ever starts to become like the other (Disco) we got originally ... it will either get sold or Old Town will give me a new one , meanwhile I like the canoe because it's performed just as I expected , does what it's needed for ... and hasn't changed so far . This canoe cost me 567. bucks new in 06 .

It will be a dead poly…

100 percent correct
If I compare what you and and the original poster are saying about storing them resting on the gunwales, the two of you are in 100 percent disagreement.

Kinda like …
trying to return a dead “poly” canoe.

“It’s not warped.”

“Yes it is.”

“No it’s not.”

“Yes it is. It’s warped, oil canned, deformed, sagging, full of woopdeedos, concave…it’s toast.”

“Oh, I guess it is. Well then, can I interest you in Kevlar?”