OT Canoe Stored Under Deck - Good or Bad

Are you saying that
this is not a concern for this canoe since I believe it has vinyl gunnels?

With due respect to your deck question,
there are other considerations you should look at.



What is your intended usage?



What model of OT canoe is this “under the deck” canoe?



I am not trying to hijack the basis of your post, but usually there are other issues of consideration for a canoe purchase. What may appear to be a “nice canoe” in looks may not be the canoe for you in functionality.



Good luck!

Yes
I don’t know if it’s completely impossible for a Royalex canoe with vinyl gunwales to get cold cracks, but I bet it’s nearly impossible, and certainly it’s exceedingly rare. It gets cold in Wisconsin and it’s not much warmer in the average storage shed than it is outside, yet when people talk about the risk of cold cracking it’s always mentioned in conjunction with wood gunwales, not vinyl.

I bet that caone is fine.
Cold cracks very unlikely and if it has them you will see them plain as day when you look at it. They are obvious.

It’s the ground or water that transfers
You take a canoe off a car top where it has been sitting in the sun and place it upside down on the ground. The temp of the aluminum that contacts the ground and within a few feet of it will drop to near ground temp in seconds. The RX hull will take substantially longer. The reason the rate plays into it is it magnifies the difference in expansion and contraction until both hull and gunwale reach the same temp. Whether you buy into the theory or why it happens or not, I have seen cold cracks on RX boats with aluminum gunwales. I know it happens. This was an explanation I was given by one boat shop and it makes sense to me.

Makes
sense with the different expansion rates especially in the situation you describe.

Depending on where you live
storing a boat under a deck in a poorly ventilated area is a bad idea.



Not applicable to this boat but I have seen galvanic reactions between humid soils and brass mostly in boats kept in warm climates under a shelter but with no airflow.



In my area there are lots of things living under the deck in the winter and gnawing damage is always possible, though I have not stuffed anything under there to check.

under a deck is usually well ventilated
It does tend to be a little more humid since it is shaded and the dirt that gets wet doesn’t dry out as quickly, but the air exchange rate is quite high. I keep some stuff under my deck because it needs ventilation.

Maybe, but I’m skeptical

– Last Updated: Mar-26-14 8:50 AM EST –

For a number of reasons, I'd have to hear this from someone I know who actually saw it happen. There are just too many cases of people noticing something and thinking it just happened, when what they saw had actually been there all along, and then misinterpreting as a result. Plus, there are some really basic reasons for doubt.

1. When you lay a canoe on the ground, it's nearly impossible to find a spot where more than just a few inches of the gunwale are actually in contact with the ground. There'd be no way to cool a substantial portion of the gunwale in this way, and it can't be blamed on heat transfer to other parts of the gunwale because heat would be reabsorbed along the way by the same process it was lost at the point of soil contact. I can see the hull itself being much warmer than air temperature near the ground, but Royalex also has a lot of "give" to it when it's warm, which may be part of the reason cold-cracking is normally thought of as something happening in sub-zero temperatures rather than something that happens in paddling-type weather.

2. It would be hard to believe this happens with exposure to cold water as well, since water can never be all that cold in the first place or you aren't going paddling in it (32 degrees at coldest).

If your boat-shop guy actually saw this, that would be interesting. But it usually pays to be careful about just believing everything that people in a particular business believe. Haven't you ever run into people with years of experience who totally misunderstand certain concepts regarding the products they deal with? This happens all the time in the automotive industry, and I meet them in my line of work all the time, especially excavators who have been moving dirt their whole lives who have several wrong ideas about the nature of frost in the soil (how it forms, how deeply it propagates and why, etc.) or the mechanics of soil compaction. Just because someone works with a particular product doesn't mean they don't also jump to to false conclusions or believe unsubstantiated ideas that get passed along. So to me, this kind of thing really needs to make a lot more sense before I'll just believe it just because some guy says it's so.

All that aside, the main topic is boats in storage, and I wonder, have you ever seen a Royalex canoe with aluminum gunwales? I haven't. Some have aluminum inserts, which of course would be buffered quite a bit when it comes to temperature change.

Additional factor - more than skeptical

– Last Updated: Mar-26-14 12:55 PM EST –

I thought of something else, which is so incredibly obvious I don't know how I overlooked it before. Before going into that, it helps a lot to fully explain what causes this cracking. It's not simply a matter of two lineal bodies expanding/contracting at different rates. That's the gist of it of course, but if that's all there was to it, the first thing you'd see is deformed holes where the screws go through. In actuality, this effect is multiplied by the fact that the rim of the hull is being "stretched around" the framed shape established by the inwale portions of the gunwales. This is important because it explains the tremendous propagation of the cold cracks downward from the gunwale. It also explains why loosening the gunwale screws helps so much. It reduces the dimensions of the inwale (simply loosening the screws would have no benefit in terms of two lineal bodies in contact with each other - the screws would still get forced against the holes in the hull, deforming the holes and/or exerting force on the hull). Imagine stretching a hose over a male fitting. If that fitting is even a tiny bit too large, the amount of stretching that's necessary within the sidewalls of the hose is multiplied tremendously. In the case of a canoe, the rim of the hull is being stretched around the elongated-football shape of the gunwales, and if the hull shrinks even a tiny bit in comparison to that framework, it simply tears.

And THAT is the reason that the thing your boat-shop friend is telling you can't possibly be true. Cold cracks are caused by the hull being stretched, then failing under tension. Even if the gunwale could be cooled substantially as you describe while the hull's temperature change lagged behind, and even if this occurred over the whole perimeter of the boat rather than just a small section, you can't overlook the fact that it would have the opposite effect as what's described above. Rather than stretching the rim of the hull, it would compress it (so this time the force would be exerted by the outwale rather than the inwale). It would be like shoving a rubber hose inside of a pipe with a tight fit, not stretching it over a larger fitting. The rim of the hull in this case would be in compression, not tension, and you can't rip a material by placing it in compression. It might buckle or wrinkle, but it won't tear. To get the proper kind of force, you'd need to suddenly heat the gunwales to a high temperature. How is that going to happen, especially with a material that will transfer any excess heat to its surroundings as efficiently as aluminum?

cold cracks happen with aluminum
I have seen it. I did not do extensive research on why, just took a boat repair guy at his word because it makes sense to me. You are reaching in some cases. When I flipped my canoe over, it tilted to one side, but nearly the entire gunwale on that side touched the ground. You’re over simplifying to think cracking is just tearing from pulling apart also. But I really don’t care if you accept the explanation; who knows - by some miracle you may be right. But please don’t give people the impression that cold cracks don’t occur with aluminum.

Cold Crack Definition

– Last Updated: Mar-26-14 3:11 PM EST –

Cold cracks of the type that folks normally talk about ARE caused by the hull attempting to shrink beyond the physical limitations imposed by the gunwales. The situation you describe will not cause the hull to shrink relative to the gunwales - it will cause the gunwales to shrink relative to the hull. The nature of the cracks propagating downward away from the rim and eventually fading out can only be explained as excess tension concentrated at the rim, with the stress dissipating with distance from that margin. If you think you can cause cracks of this nature by compressing a material sandwiched between two confining layers, you are choosing to ignore some very basic physical properties.

I'm not saying cold cracking with aluminum gunwales can't occur. I'm saying that if it does occur, I'm sure it's by the mechanism everyone already knows.

Again, I've met way too many people who do technical work and do a good job yet still carry false notions about the way things are and why they happen, to simply "believe" such a person without applying any logical reasoning.

I know you don't care whether I believe your explanation. I only responded because you put some words in my mouth that I never said. Still, it would be cool if you could provide some sensible reason that shows how such cracks (wider at the edge, fading away with distance from the edge) could form in a sheet-like material when the edge of that material is in compression. Simply telling me that it can happen isn't the same is providing a reason that squares with the physical world.

You just need to look at it -
only way to tell. Some situation under deck is fine. Others not so good.

Under deck and stains
Under deck is fine. But the stains from dealing the deck may be hard to get off depending on the material of the canoe. I usually protect our kayaks before doing that and have been able to clean off any misses on the fiberglass hulls, but it doesn’t come off easily. I suspect I would have a much harder time if I didn’t always move the kevlar canoe first.

You’re in NC and talking about cold
cracks? How did cold cracks even enter the conversation?



And aluminum is not ash. I have NOT heard of cold cracking with aluminum gunwales. One reason is that there are very, very few Royalex canoes with aluminum gunwales. Ash, or vinyl (with a floating aluminum insert) is the rule.



Are you the one who brought cold cracking into the discussion? Why?

I had one crack in VA

– Last Updated: Mar-27-14 10:34 PM EST –

and I am only about 60 miles from the NC state line. Mine had ash gunnels though and it dropped to about -5 degrees.

Minus five and ash gunwales could
do it. But it isn’t worth speculating about aluminum gunwales, because except for the old Blue Hole OCA canoes, aluminum on Royalex is rare.

I’ll be poling
A canoe tomorrow that just emerged from a snowbank for the fifteenth year…just saying.

Buy it.
What’s worse, a canoe stored under a deck or a canoe that is used all the time and sits on the beach baking in the sun? Negotiate a fair price and enjoy it. Anything that could be wrong will be obvious in seconds.

should be fine
I’ve stored boats on a rack under my deck, which is about 8’ off the ground, for years. They have been fine there. As far as the one you are looking at is concerned, I would suggest taking a look at it to get an idea of the condition before you commit to buying it.