What's Inside a Float Tank?

[Mason]

Mason, do you drill at the angle of the pipe or perpendicular to the hull? Pilot bit size?

I drilled along the lines of the tubing, not perpendicular to the hull. As I used a spade bit, I didn't need a pilot bit. I drilled from the outside in on both sides--I did not try to drill all the way through from one side, which I think Alan did. Blowout was not a problem, though if you see on the pic of the dark green boat, there is some chipping of the gel coat along the edges. It was probably a dull bit. Sharp bits would be nicer. The lighter colored boat was cleaner. In Kevlar, you'll get some fuzz, which should be able to be cleaned up with a razor (though I didn't really clean mine up).

And Mike, the boat that saw all the action was my Wenonah C1W, which has moderate sized float tanks. With no other floatation, I could tow it to shore in a slow river by myself--it never came close to submerging. My Wenonah Encounter, with no added floatation, floated plenty high in a lake (after a lake snake grabbed my paddle while trying gunnel dipping). In whitewater I throw in as much floatation as the boat will hold and where I can still squeeze into it.

 

[Alan Gage]

I drilled from the outside in on both sides--I did not try to drill all the way through from one side, which I think Alan did.

I drill all the way through from one side until the tip of the bit bit just starts to protrude from the hull on the opposite side. Then I finish the hole from the outside. This gives me a little pilot hole for location and feel it helps line up both sides better.

Alan

 

[Mason]

I drill all the way through from one side until the tip of the bit bit just starts to protrude from the hull on the opposite side. Then I finish the hole from the outside. This gives me a little pilot hole for location and feel it helps line up both sides better.

Alan

That's a good idea. Maybe I did that too? danged CRS.

 

[Guest]

I actually don't mind the looks of the tug eye solution, just seems like a lot of trouble.

I put DIY flange versions on several canoes, including a couple at OEM high mounted painter line holes. Some of the winky OEM flanges were crap (looking at you Mad River) and tattered apart or simply fell out in short order.

A couple hulls did not even have a hole-softening flange, however cheesy, just a raw hole drilled through the hull. That left a sharp edge worrying at my painter lines, especially with composite hulls. It would grind away at the rope, and at the hole through the hull as well.

With accessible stems the DIY version is easy and inexpensive. Four conduit flanges, some G/flex and some hose or tubing.

P5260015 by Mike McCrea, on Flickr

The (not very) hard part was finding tubing that slipped tightly over the protruding flange sidewalls. The tubing was cut at appropriate /__\ angles so it pressed flush against the inside of the hull. Doesn’t have to be perfectly angled, even thick tubing will bend a little.

P5260016 by Mike McCrea, on Flickr

Would have looked a little nicer had I painted the flanges black, or a hull matching color first. Maybe next time.

P2160542 by Mike McCrea, on Flickr

FWIW, not that I’d recommend it today, especially not through sealed chambers, but a quick and dirty old school method to “seal” painter line holes was to use thick kernmantle rope that was a tiny bit larger than the holes. Pull a couple inches of the mantle core out of the sheath, cut it off and melt the dangling sheath together. Push the reduced diameter sheath through the hole, poke it out the other side, grab it with vice grips and forcefully pull the rope through the holes.

The rope will squeeze down, mostly sealing the holes. That was almost standard practice on home built glass WW kayaks.

 

[Odyssey]

Well all I can say is Big Jim McBob and Billy Sol Hurok are gonna be disappointed if this float tank thang doesn't come off with a bang.

 

[alsg]

For my cedar stripper, I used copper water pipe and thickened epoxy. Works great! No float tank, however.

 

[Canotrouge]

I use the traditional lining method of having a set of ropes(bow and stern ) going under the canoe and my lining lines attached o them!! It is by far the best way I found to line empty or fully loaded boats!!

 

[Black_Fly]

That's some nice work. You guys should be working for canoe manufacturers. Skid plates and lining holes are off my list as factory installations.

After looking at the thickness (or thinness) of the Kevlar, I'm skeptical that I can get enough epoxy on the joint to prevent leaks. On my Royalex canoes, I was able to get a good bead on the inside. Gonna have to ponder some more. Guess that's why they use rubber flanges and flexible tubing.

 

[ppine]

Foam or styrofoam. I have used a saw to remove broken fiberglass and kevlar several times on the busted bows of canoes. It is a chance to remove any rotted styrofoam. Then the contour of the hull can be restored with spray foam and some work with a file and sandpaper before new glass and epoxy.

A hole saw is the right tool for the job of drilling the hull. .

 

[Guest]

Update: decided the angle of the hull is prohibitive with a solid flange, hard pvc. I'm done. A hitch it is

Blackfly, I’ve been pondering the issue of the angle of the solid flanges set / \ against the stems, and the PVC pipe passing straight through the flange being badly mis-aimed at the other side. There may be a solution, or two.

The problem with the flanges is that they are mounted flush against the hull on either side, so the ½” long inwall protrusions that stick through the hull are not aimed at each other; a piece of straight PVC pipe won’t come anywhere close to the flange on the opposite side.

A possible (I have not tried this) solution with PVC pipe might be to heat it up with a torch and induce some) shaped bend, so that when the pipe got to the other side it would be aimed at the opposite flange.

That could also be done with a length of old garden hose, which tends to have a bit of coiled pre-curve to it anyway. The piece of hose shown in the photo is thick heavy duty stuff, with reinforcing strands molded in. G/flex epoxy held the (nylon?) conduit flanges and the (vinyl?) hose very secure and waterproof.

With either PVC pipe or hose I would cut the end to be passed through into a point, so that it would be easier to get started through the opposite flange and then pulled far enough out to cut off flush with the flange.

Might be best to try that first with an old Royalex hull, to get a feel for how it works. Or doesn’t work. At least with a no-chambered RX hull if it didn’t work you could simply add larger tubing or pipe to the outer diameter of the flange protrusions.

 

[Black_Fly]

Would leakage be avoided better if the pipe/tubing went inside the flange neck? Then the seal to the hull would at least not be an issue.

 

[Guest]

Would leakage be avoided better if the pipe/tubing went inside the flange neck? Then the seal to the hull would at least not be an issue.

I dunno. I guess it could still leak into the chamber between the flange and hull if the epoxy sealing was poorly done, if mostly teeny seepage.

Attempting an outer flange with sealed float tanks I see no option other than pipe/tubing going inside the flange neck. The line, passing through the conduit flanges I have used, if tied a simple loop would be considerably smaller than hand comfy lining ropes.

There is some seriously freaking strong Spectra/Dyneema/etc rope in smaller diameter, and that could be passed through a pipe or tubing inside those flanges tied and in a loop for attaching more hand comfy painters or lining ropes.

For painters or lining ropes size does matter. I am really fond of BlueWater Ropes 5/16” floating rescue rope as painter lines for strength and hand kindliness.

https://www.bluewaterropes.com/produ...r-rescue-rope/

It is my canoe, a continuing conveyance I may kinda need to get out, and contains the gear I need to survive comfortably; this is not a time to cheap out on crapty, UV’s to dust in a year Home Depot rope. If you are going to spring for some ca-ching, let it be good cordage.

What epoxy is best?

I wrote (nylon?) flange and (vinyl?) hose because I was uncertain what either were made of. In any case, and in that unknown (? material) case I would use G/flex.

I found some un-used hose and spare conduit flanges in the box of painter hole parts.

P4190016 by Mike McCrea, on Flickr

P4190019 by Mike McCrea, on Flickr

As before, the outer edge of the flange, the part outside the hull, is 1 1/8” in diameter. The inner neck hole is 7/8” diameter and the protruding neck that sticks through the hull is ¾” long (though that part could easily be cut shorter).

FWIW the flange is stamped “Carlons 1/2” E996D PVC. So PVC, not “nylon”.

A little Google and that flange is actually called a “box adapter”

https://www.steinerelectric.com/Prod...1-2-inPVC-1341

 

[Black_Fly]

I found the box adapters at Lowes. Looking for pvc hose.

 

[Guest]

I found the box adapters at Lowes. Looking for pvc hose.

Just for funsies I grabbed a length of PVC pipe off the rack. To be specific ½” SDR 11 CPVC Flowguard drinking water pipe. I was mistaken about the flanges with inset pipe not having sufficient diameter for decent hand kindly rope. Half inch ID is plenty of room.

That pipe fits perfectly inside the flange neck, tight but not so tight that I had to force it. The pipe is relatively flexible as is, but I’m going to cut a piece off, hit it with a heat gun or propane torch and see if I can induce the helpful bend.

I am now intrigued by the concept, but are you sure you want to drill those holes?

 

[Iskweo]

Well, since you asked, here is what I found. Dont worry, I didnt cut them open just to show you...they are waterlogged and need cleaning out. It really almost looks like seat cushion foam. Very absorbant. Which is why a 14 foot canoe is almost too heavy to lift.

It was a $100 boatt impulse buy...leaky keel and no seats. Nice hull shape though, I may use it as a form.

 

[Black_Fly]

Lots of flexible tubing labeled clear pvc vinyl tubing. Will g-flex adhere to that?

 

[Guest]

Lots of flexible tubing labeled clear pvc vinyl tubing. Will g-flex adhere to that?

Yes. G/flex stuck to the flanges, which are PVC, and to the hose, which I suspect is vinyl, and adheres vinyl pad D-rings.

I tried heat bending a piece of PVC pipe. A couple minutes with a heat gun and that PVC took and held the bend. More of a vee than a bend; I could have bent it more incrementally along the length.

P4200002 by Mike McCrea, on Flickr

I pointered one end of the pipe so that it would be easier (in theory) to blind aim and push through the opposite flange.

P4200003 by Mike McCrea, on Flickr

7/16” rescue rope fits inside the pipe easily, with enough slack to slide.

P4200005 by Mike McCrea, on Flickr

Blackfly, if you opt to try this do you perhaps have an old glass beater available, with or without float chambers, to use as a trial install? I always learn something I wished I’d known or thought of the first time around, and would like to have a success under my belt before drilling 7/8” holes in a Prism or Magic

 

[Canotrouge]

All of the one I've worked on were filled with foam, styrofoam, or something similar!

 

[Guest]

All of the one I've worked on were filled with foam, styrofoam, or something similar!

The couple float chambers I repaired on composite hulls (both 20+ year old boats) needed only to be re-glassed in place in separated areas. I couldn’t see anything inside the barely open chamber; should have poked a wire in there to feel around.

it would be worth asking Wenonah and Northstar directly. Let us know the manufacturer’s answers.

Anyone feel like making inquiries of various manufacturers? I’d like to know, especially about modern canoe float tank construction. If it is some potentially decaying, absorbent or short-lived material such as Iskweo found I’d really like to know.

Every Grumman and Monkey Ward Sea King we ever owned eventually shed wee crumbs of ancient Styrofoam in the bilge after a capsize.

Edit correction: One old abused Sawyer had the stern stem worn completely peek-a-boo look inside through; if there was anything in that float tank it was long gone. I had to carve and stuff a piece of minicel in that void to get the stem shape glassed/rebuilt. It was close to original shape. That was 20 years ago and that canoe is still in use.

 

[Mason]

All of the one I've worked on were filled with foam, styrofoam, or something similar!

I just checked my two Wenonahs-- 1983 CIW and a 2016 Voyager. Both tanks were empty, sealed with a rubber plug. My 1990s Clipper WW III is unknown--no access inside.