Remove canoe flotation bulkheads

I would like to permanently remove the aluminium flotation bulkheads in my grumman canoe. I plan to replace the flotation material with air bags but do not pan on replacing the aluminum bulkhead covers. I may attach a small bar to the gunnels for support and to hold the air bags in place. Has any one ever done this? Any recommendations?


Don’t do it.

– Last Updated: Oct-14-13 7:55 PM EST –

Why would you?
Airbags are supplemental floatation devices for boats that already have "some" floatation. They are not the only floatation in any boat.

I hate aluminum canoes as much as the next guy, but I wouldn’t do that either.

Thanks. I need to replace the flotation material as well as a few rivets. I figured it would be easier (and ultimately lighter) to just leave the bulkheads off and replace with airbags strapped to the gunnels.

I’ll need to rethink my plan.

Not really

– Last Updated: Oct-14-13 9:09 PM EST –

Many current performance composite and poly whitewater canoes depend on air bags as their primary floation. The L'Edge, Prelude, Option, Shaman, most Millbrooks , Blackfly, etc come to mind. However why one would want to take out the floatation on a aluminum boat escapes me

You can buy that material in sheets,
… and maybe even in blocks. I used to suggest using closed-cell foam insulation (the stuff that’s either blue or pink), but some people on this board claim it can become waterlogged. I’ve never seen evidence of that, and I myself don’t believe it’s a genuine problem (pieces we’ve dug up that have been buried for years in saturated soil are never the slightest bit waterlogged, and the material is actually recommended for use as insulation below ground in direct contact with soil, which would NOT be the case if it were prone to taking up water). However, if the naysayers scare you, you can use “the white stuff” which consists of compressed polystyrene beads (it’s also cheaper, but is harder to cut into precise shapes, and tends to fall apart during handling). With either material, if you can’t get it in large enough blocks, you can use material that comes in sheets. Just stack custom-shaped pieces in the float chamber. Get sheets in a couple of different thicknesses and you should be able to completely fill the chamber.

use over size rivets for replacements …
… keep the bulkhead .

Use 2 part marine grade (2 lb.) closed cell polyurethane expandable foam for replacement .

A standard kit for a canoe would have 1 qt. part A , and 1 quart part B … mix and pour (read directions / check out “how to’s” on-line) . With the 1 qt.(A) + 1 qt.(B) kit you will get aprox. 2 cubic feet after expansion is complete . That sounds like just pour 1/2 the mix in each end , but caution here … you need to know if each end can hold 1 cu.ft. expanded foam , you don’t want to blow the ends/bulkheads out , and there is a way to know how much you can get in there before hand .

If you want to know I’ll tell you how , just ask .

al flotation.
Keep the factory flotation. What if you forget the bags? What if you sell the boat or lend it to someone? Aluminum boats need more flotation, not less.

cutting polyester
A heavy-duty 24V power source, heating-element wire, a variable resistor and insulators and you can melt-cut polyester blocks in any shape imaginable - AND there will be no pesky white fluff! Smells a bit though. Just string the wire taunt tight between the insulations, adjust the amperage to desired level of heat, and work the material around it. Like a bandsaw.

did you remove the bulkheads?
I bought an old 1960’s Grumman 15’ to beat around in. I’m concerned about the floatation material behind the bulkheads. Can you tell me if it was/is originally foam filled, or something else?