What is the best design for an an aluminum foil penny boat?

Answer 1

The best design for an aluminum foil boat would be to try to make it cover as much area as possible. although you still want edges to hold the pennies, you want to try to cover as much space as possible. Also if your trying to design a small aluminum foil boat try to make a sphere shaped boat.

responding to the above answer ...

Maximizing a "boat's" load carrying capacity, IS a function of maximizing its volume below the surface. BUT, if it floats, you can add the "open to air" area to your material surface area as well. Free surface area! Yeah! Increasing the available area, increases the volume. So, a half sphere is best.

What about construction rules? What considerations regarding cutting, taping, gluing, or brazing are involved?

If you are given a single piece of foil and can only fold it or manipulate it, then a dish shape would be best. The dish shape will conserve the most area/volume for displacement, as it will minimize the amount of area lost due to folds, and maximizes that free "open to air" area.

Take a ball point pen and score short lines near the outside edge all around the foil (without tearing it of course). These lines should be parallel with lines that radiate from the center out. This should have the effect of creating a "lip" around the outside edge. Stack the "cargo" at the center and move outward as the "boat" starts to become unstable.

I wonder, however, if there might be some creative way of trapping air beneath the "boat" to get some more free "open to air" area (like an egg carton). There might be some total gain. Although it does not seem intuitively possible, the trapped air WOULD displace volume. I think the best possibility would be a rolled over lip on the edge. If the "foil" was stiff enough to prevent deflection/deformation, I think it would work ... carbon fiber.