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The Duct-Tape Catamaran

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brino

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Let me start by saying I am NOT one of those people that ascribes mystical powers to duct-tape.
I loathe the saying about only needing two tools (WD-40 and duct-tape) as I believe neither one is particularly good for anything, especially long-term.
In fact, it's precisely this juxtaposition that makes this project interesting for me:
"How can we make boat to carry four people across the river and back using such a flimsy material."

Our local hospital has a fund-raiser where teams build rafts to race across the river.
I wanted to do something a little different.
I remembered an old duct-tape canoe that myth-busters did years ago.
But ours needed to carry at least four people.

My neighbour and I started talking and sketching.
The next thing I knew we were off to the local metal yard.
Yes there were some spread-sheets involved for calculating buoyancy and number of rolls of tape.

The pontoon frames:
==============
The plan included steel rings spaced every two feet apart.
So, first I had to build a ring-roller.
(I didn't take any pictures, so I'll have to set it up again to document that)

We used six 3/8" steel rods as ribs running front to back 12 feet long.
We used 1/8" x 1" wide steel for the rings.
The ring diameter was 18" so each ring circumference was just under 5' long.

We assembled and welded the rings and ribs, leaving the front ends free, initially....
frame1.jpg

frame2.jpg

frame3.jpg
Later the front ends were bent together to a rough hull shape, then welded.

The back end was closed with a piece of plywood cut to fit and then cable-tied on.

In order to join the two pontoons into a boat, I welded on two rectangular tubes to use as sockets for 2x4's.
socket1.jpg

socket2.jpg

There are holes in the sockets to bolt thru the 2x4's.

We covered the rings with tape to try to cover any sharp edges and weld spatter.
We also made duct-tape rings between the steel rings to help keep the next plastic layer from collapsing under pressure.
The entire pontoon got a cover of 6-mil plastic vapour barrier, using duct-tape to hold it together.
Then a full cover of duct-tape....about 5 rolls per pontoon for the outer skin.

wrap1.jpg

We even found a great way to transport it.
We extended the truck box by clamping on a couple more 2x4's, so we could hang the pontoons in the truck bed.
transport1.jpg

The test:
======
We got it basically finished one day before race day, and so took it to the fair grounds for a test.
test1.jpg
It floated great and was quite maneuverable, by paddling forward on one side and back on the other it turned sharp.
It sat so high out of the water with two of us that I speculated that anyone that fell out would not be able to climb back up.
My neighbour disagreed, so I had him try it.......I had to paddle to shore for him to get back on.
That afternoon we added a hinged, drop-down ladder to the middle supports.

Next-up, the race.
Stay Tuned!
-brino

frame1.jpgframe2.jpgframe3.jpgsocket1.jpgsocket2.jpgwrap1.jpgtransport1.jpgtest1.jpg
 

brino

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ELHEAD

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Great project for a worthy cause. You are to be commended.
 

TTD

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That’s pretty cool, Brino! :cool:

Too bad I missed seeing the race in person....but if you decide to fill the pontoons with spray foam & try shootin’ the rapids/falls a few hundred yards downstream, I will make DAMN sure not to miss that! ;):excitement:
 

brino

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if you decide to fill the pontoons with spray foam & try shootin’ the rapids/falls a few hundred yards downstream, I will make DAMN sure not to miss that!
Nope. No plans for that.
I want time to enjoy the tools I keep collecting......
-brino
 
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aliva

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To all you Americans its a Canuck thing.
 
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