HDPE for small catamaran USV?

We're undergraduate students trying to build a USV for data collection, about 1-2 m in length. In terms of material to use for the hull, we've heard HDPE is used in Kayaks and is super durable. On the other hand, stuff like plywood and fiberglass is the convention but would be somewhat harder for us to build. Should we proceed with HDPE for a catamaran USV of that size? Thanks.

 

HDPE is usually injected into a mold, which is expensive. Maybe try shaping your cat out of a solid lump of expanded polystyrene foam, or similar, paint it with acrylic paint to seal the foam, so it doesn't melt by dissolving, then fibreglass it, simple. Any modifications - just cut and re-glass, with cheap polyester resin or polyvinyl, or whatever is convenient. Be careful of the thin parts, they snap easily until the resin/glass is cured. Or glue some foam pieces together pre shaped, then finish shaping before paint, then resin/glass. Build two at same time, one as backup.

 

If you can design the hulls with developable surfaces, you may very well use polyethene sheets. For the suggested size you could even use low density PE; the factors driving the structural design are expected sea pressure and allowable deflection. You can weld the sheet panels and stiffeners with a handheld hot-air gun, preferably with built-in temperature regulation.

 

If your scale model is to be used as a research project, you must be careful about weight and weight distribution. The selection of materials that you use needs to keep the weight variable in mind. For example; gathering data about pitch and roll will need attention to how weight is distributed in the structure.

Why do you believe that using wood, such as plywood, would be more difficult to build than with HDPE ?

 

Guys, thanks for all the replies. We went with pipes, folks in my team thought it was better. Sorry for not replying, didn't notice as I'm not active here.