chipboard tend to chip, and splinter. It would probably work, but for the number of hours you are going to put into the project for me it is worth avoiding the hassle of chipping and crumbling edges to spring for some decent plywood.

Once you've used chipboard a couple of times you tend to avoid it for anything other than sheathing walls/roofs where it is ideal.

Check the phonebook and phone around - I was able to find a place in San Jose that was selling 9-ply 5foot by 5foot 1/2 inch birch plywood for $19 bucks a sheet.

> I am just beginning construction of an expedition single. In regards to
> the wood used for the forms, is it necessary to use plywood, or can I get
> by using chipboard as the form wood material?