Folded up my first seat made of 2.5mm polished aluminium - looks really good. Much better in real life than in photo

Still needs to be welded up - a b*stard to fold though.

Description

cool but is there going to be some sort of frame as it looks a tad weak

Once welded up will be plenty stiff enough.

very clever stuff, wish I could do that

I'm sure you'd be able to do that here are some free plans. Think ChrisG's book also has a similar plan. Make it with 1mm steel if you find that easier to weld - probably need some stiffening strips if you do that though.

http://www.rorty-design.com/files/Rorty%20Basic%20Aluminium%20Seat%20Pattern.pdf