Here is a negative comment on using plastic ribs: I certainly have nothing against trying new techniques, however...

The only reasonable manner I can think of to use HDPE for "ribs" is like a folder, in bulkheads which are pierced by holes through which you stick your legs, etc. This is what Tom Yost did, and his method is plenty strong.

But, from the original post, I believe you were considering using the plastic more like traditional ribs. Strips, bent and shaped to go from gunwale to gunwale. As such, they would need to be so thick and heavy to get the strength you need, that one wonders why not use steam bent (or heat gun bent) wood. Wood is lighter, cheaper, stronger. It will rot, but only if you let it stay wet for months at a time. Stored dry, it should last for 10 years plus. And when you are finished with the thing, it returns to nature very easily.

Rick

: I'm just trying to bounce this idea off the wisdom of the board. What would
: be the pros and cons of building a SOF with polyethylene ribs? The
: material is relativaly inexpensive, indestructable and very easy to form
: using heat. I'm mainly thinking about the ease of building and the impact
: resistance, one could even cut ribs from a poly barrel though I imagine
: you'd need something thicker, like 3/8" or so to get enough
: stiffness. Any thoughts ? sorry if I have disgusted any traditionalists