I wonder if 25 gauge is strong enough to support the forms with out sagging. otherwise it sounds good. you could add support in the middle. My wood strongback 2 x 4 cost about $10 as I remember.

I just called and got a cost on a "steel 2x4", 18' long, 25
> guage steel. The cost was less than $4.00 and the guy said they had over
> 400 in stock.

> They are the same size as your standard pine 2x4 but made of galvanized
> steel. They are easily cut with tin snips - to fit end forms on. Drywall
> screws bite into them like a wild dog.

> They WILL NOT WARP - unless you sat on them, in which case you deserve
> what you get.

> Can anyone think of a good reason why these would not work?

> Also, how about homosote for forms material? It is "particle
> board" that is made of recycled newspaper. The paper is soaked until
> it is mush then heat and pressure is appled. It is sold in 4x8 sheets
> 1" thick and can be easily cut with a saber saw It is heavy, dense
> and should hold a staple well. It too would be very dimensionally stable.
> It's sold locally at Home Depot.

> Thanks, Carl