Rolled edges?

[mhorowit]

Thinking I might make my own 'ribs' to replace the rusted ones in 88M's horiz.stabs, I took a good look at what it would take to bend my own.
I noticed the edges were rolled inwards; probably a strengthening measure not unlike what they do in wing ribs.

How would I go about forming a rolled lip?

[crispy critter]

Re: Rolled edges?

Mike,
The rolled edge does give a little extra strength but I think the main reason they do that is to prevent the sharp edge from rubbing or cutting through the fabric.