cardboardcanoe

Sunday, September 12, 2004

Sourcebook: Paints, Finishes and Adhesives

Sourcebook: Paints, Finishes and Adhesives: "'Pristine' and 'Crayola' no-VOC paints"


In trying to decide where to take this. The water cleanup glue did not stick to the constrution foam. The best place to go from here is: Non-Toxic Stitch and Glue Canoe.

This way people can work with cotton polyester and low VOC adhesives and finishes to make a great boat with their kids. A boat big enough to share. A fair budget might be $80 for everything?

Let's see how it goes.

Saturday, September 11, 2004

Boatbuilding Lumber Supplier List

Boatbuilding Lumber Supplier List

Cardboard will work for a canoe that is stored indoors and used for less than 4 hours at a time. The idea is that humidity on the inside and outside of the cardboard will equal out over time. So if it is kept in a dry environment all the time except when being used, it will be fine. But if the canoe is kept in a steamer all the time it will turn to mush.

Alternative materials are plywood or construction foam. Each cost about $8 a 4'x8' sheet. $16 for this project. I want to use a 60/40 bed sheet to tape the seams rather than fiber glass with the non-toxic glue I have already purchased. Plywood is hard and sharp enough to rip a bedsheet - it would require fiber glass. Foam will not rip the bedsheet. Will the non-toxic glue stick to foam?

If it does the material will change from cardboard to foam.

Monday, September 06, 2004

smugmug - Ed (ecf) : Cardboard Canoe

smugmug - Ed (ecf) : Cardboard Canoe

Images at this link show progress and motivation. The origonal flat bottom conoe is wonderfully easy to build, but as this picture shows: two kids almost sink it!

Sunday, September 05, 2004

free plans for a canoe

free plans for a canoe

This is the link to the canoe that is too small as an attribution. Let's look at all the extra space on the sheet thinking, "I can make it longer, and there is even room in the gaps between the sides and the bottom to make the bottom into a V. In addition to helping boyancy (floatieness), the V helps tracking and can provide strength?

Here is the original panel drawing:



Here is the one showing white space that can be appliedto add length (speed), width (stability), and pints below the hard edge/corner (speed and safety):



Here is a half scale model:


On this next set of pictures the region of discussion is the relatively unsupported edge of the hull that is nearest the carpet.

Here you can see the wavey left side that was cut smoothly from a precoated sheet, but never edge soaked with glue. It is too flexible to take a smooth arc! In the lower left forground you can see it bulging out on either side of the tape cross brace tail that is barely visible.



Here you can see the right hand side cut with sissors (bad) but edged soaked (good). It makes a smooth curve because the edge is much stronger!




On this model one seam is done using hot melt glue (slow to apply but sets quickly, does not want to form a nice shape for putting tape over) and one seam using poly urethane caulk (too flexible and takes a long time to set but applies quickly and can be dressed with a plastic spoon to make a nice shape to put tape over).

Polyurethane adhesives are stiffer and fast set formulations are available but the ones I know about cost five times as much.

An old iron with an aluminum sole plate, with the point filed into a gentle round to make nice shapes for putting tape over, would go a long way towards solving the problems with the hot melt glue.

Saturday, September 04, 2004

Johncanoe construction

Johncanoe construction

This is a link to another builder who experienced frustration... Here is a progress report:

Sissors are a poor substitute for an X-acto knife when cutting the outlines fo the shape. X-acto knife works great!

Coating one side of the cardboard before cuttting into individual pieces works great! Much better than coating after cutting.

If the side you coat is what ends up on the inside of the boat, the glue drying warps the cardboard in a way that makes the boat better! Picture will be forthcoming.

Used hot melt on one side and urethane calk on the other... tradeoffs both ways. (-:

Thursday, September 02, 2004

Kayak Stability and Leaning + progress report

Kayak Stability and Leaning

This link is to a somewhat confusing article about stability.

Here is my understanding, with the idea that we need to find a way to put more pints down below the waterline:

1) Shapes with hard corners near the waterline, like the empty yogurt container, are very stable. They call this a box shape.

2) Also very stable are v-hull designs.

3) Stability improves if the hull flares out above the water line -but paddling becomes more difficult because you have to reach further to get to the water.

Here are some gratuitous graphs:






The conclusion of the matter is: by adding a v-hull to the bottom of our flat bottom "unsuitible" design we can increase boyancy without messing up stability!

What does that mean in a practical sense? Visualize the flat bottomed boat bottom side up so that the bottom looks like a serving board. Put pints of yogurt on top and shape them into a ^ hat shape. Make an addition to the canoe that covers up all the yogurt. This is the improved design with more boyancy and good stability.

Wednesday, September 01, 2004

Pick your poison

www.Titebond.com

Most waterproof glues and resins are poisonous. This one is not and will be the resin of choice for prototyping... We might use hot melt for the fillets.