why are aluminum canoes unsinkable

[NYGiants]

i was always taught that even swamped an aluminum canoe will float. i know the ends have something to do with it but im not really sure. so why are they unsinkable

 

[Fireman431]

Re: why are aluminum canoes unsinkable

A piece of concrete weighs more than the amount of water that it's displacing, therefore it sinks. A piece of styofoam the same size weighs much less than the amount of water it's displacing, therefore it floats.

I had never heard that an aluminum canoe wouldn't sink, but I guess it stands to reason. It all comes down to volume/mass/weight. Because aluminum is so light, it's mass doesn't weigh more than the water it's displacing, therefore, even totally submerged, it still floats. I would think there's some type of flotation in there, though. Metal sinks.

Good luck getting the water out of it and climbing back into it, though.

 

[Tim Frank]

Re: why are aluminum canoes unsinkable

They usually won't sink because they have enough flotation (foam or something equivalent) in the bow and stern.

No guarantees though...if you need to know for sure that yours has some buoyancy when filled, test it in a safe and recoverable location.

Bottom line is... aluminum does sink.

 

[Bondo]

Re: why are aluminum canoes unsinkable

Bottom line is... aluminum does sink.

Ayuh,... Boat, Canoe, or a pie plate,... They'll All sink without floation...

 

[Mike Robinson]

Re: why are aluminum canoes unsinkable

I have an alumium canoe and have sunk it on purpose. It is slightly positively bouyant and will sink if someone is sitting in it.

 

[scoutabout]

Re: why are aluminum canoes unsinkable

This is why I'm not too keen to dump my aluminum sailing dinghy. It's old and the foam under the floor is probably very waterlogged. Problem is I can't get at it without drilling out a lot of rivets.

So....I'm considering jamming empty, sealed 2 litre pop bottles under the seats along both sides and strapping some closed cell foam up under the deck. That just might tip the balance (as it were) in my favour should we dump. Meanwhile, I'm never further out than a leisurely swim...

 

[robert graham]

Re: why are aluminum canoes unsinkable

Except for flotation, they are definitely sinkable! Good Luck!

 

[drrpm]

Re: why are aluminum canoes unsinkable

There is foam in the bow and stern compartments that keep them from sinking. A polyethelyne canoe won't sink because it has a thin foam core. Kevlar canoes can sink if they don't have flotation bags. Whitewater canoes are usually outfitted with large flotation bags and webbing to hold them in place. Some old school whitewater tricks are to lash a truck innertube or put styrofoam blocks into the canoe.

 

[Home Cookin']

Re: why are aluminum canoes unsinkable

scoutabout, think about a bladder of some kind, such as a truck inner tube--but that takes your hold space. Also swim noodles are cheap and easy to work with. But if you add bottles, noodles, etc. you will need to sink it once to see if you have reached positive floation. You may have a weighted keel to counteract. If so, you're sunk.
Any boat with floatation can roll when swamped, so floatation is of moderate utility, especially in cold water.

 

[shrew]

Re: why are aluminum canoes unsinkable

As stated, aluminum canoes should have a welded bulk head in the bow and stern filled with positive floatation. Unsinkable is relative. when filled with water it will sink the gunnels to the waterline. It will be extrememly unstable and will roll if you try to climb into it, but it should not sink to the bottom and you will be able to hold onto it while it's 'floating' about 1" above the water. I've swamped many canoes of a variety of types over the years, both aluminum and Royalex. The Royalex and the other 'plastic' canoes usually have an outter and inner with positive flotation sandwhiched in between with a cap on the gunnel for rigidity.

As a kid a buddy and I swamped one and swam the swamped canoe almost 1 mile to get back to shore. We put on the PFD's and held onto the boat and spent a few hours slowly dragging it to shore.

I've never seen one actually sink before. You will have a pretty good idea if you have saturated the positive flotation in a canoe to the point where it won't float anymore. The boat will be very, very heavy and will paddle like a raft. It will sit low in the water even without occupants.

 

[jeeperman]

Re: why are aluminum canoes unsinkable

Also if there is any tubing such as inside the sheet metal to form the gunnels or used as the ribs or the seat platforms, etc. will keep it from sinking 100%.
At least until they fill with water also.

If it is 100% aluminum with no air pockets and no foam anywhere, it will sink.