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Re: (gear) Zeppelin shape

Subject: Re: (gear) Zeppelin shape
From: "Walter Knapp" waltknapp
Date: Mon Jul 31, 2006 1:29 pm (PDT)
Posted by: "Derek Holzer"

> Sharp corners catch wind. Simple as that.

They create eddys in the windstream that make noise. You want the
outside surface of your windscreen to be smooth and rounded to avoid this.

> Maybe buy some tea strainers that match the diameter of your tube?

If you are using the plastic canvas mesh it will mold to a shape when
heated. Boiling water is close to the right temperature, though it molds
easier if heated a little above that. Heat in the oven to do that, on
something like a non-stick cookie sheet. Maybe heat your shape mold too.

Craft shops also have at least one size of premolded plastic canvas. In
2 piece sphere and egg shapes.

The original zeppelins were made out of painted fabric mesh. Like that
of older onion sacks but larger mesh. You can buy this material by
looking for latchhook rug making backing in craft shops, it's cotton
with some sizing to stiffen it. Soak the material in water, mold to
shape, dry and paint it to stiffen it before removing from the mold.
Build up the paint a little and you have exactly the same as the oldest
commercial zeppelin I have here. When the last layer of paint is still
wet you could use that to adhere the filler of thin fleece or very fine
screening. This whole process should be even easier than thermal molding
the plastic canvas material.

Walt





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