Tuesday, July 15, 2008

Tech Tip Tuesday

Canoes have some interesting curves. These curves can make it very difficult to clamp things in place. For example - when I teach my students to build a canoe, we simplify the construction of the canoe's bottom by building the "football" as two separate panels. We then cut the panels to meet in the center of the hull and glue them together.

Here's the rub, 'tho. How do you hold them while they glue?

Innertubes. Flat bicycle innertubes.


When I bring them out, my students are always skeptical, but become converts as we use them.

We get the scrap ones from a local bike shop and use them like big rubber bands to hold panels down and even for laminating the outer stems onto the hull. The only thing you need to do is to screw some blocks to the strongback like cleats to turn the innertubes around. The rubber doesn't stick to the glue and voila! There you have it. The nice thing is that if you need to apply more pressure in a particular area to close up a gap, you just stick a block of wood with some tape on it (as a release layer) under the innertube.

Three cautions on this method, tho -
  1. Be careful of where there might be punctures in the tire - it may break in that area when pulled.
  2. Be sure nobody is in line with an innertube when it is being pulled tight or released!
  3. Cut out the section with the valve to keep from denting the wood or hurting someone.
It's cheap, and it's remarkably effective!

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