How much weight for glue up top on torsion box

[Paulh Tremblay]

I ended up using boxes of books. I'd say there was probably 200 - 300 pounds across the 4 X 6 foot surface. I probably could have gone with even less weight, but the final product seems nearly perfectly flat.

I did my own experiment of gluing a flat piece of mdf on the edges of two other pieces of MD, using only 3 books as weight. The next day I could not pull the assemblky apart.

http://festoolownersgroup.com/member...asic-festools/

[Paulh Tremblay]

I am curious where you found a floor flat enough to be a reference surface though. I assume you have it shimmed somehow(?). .

I didn't use a door. I followed the method called for in most plans, of establishing a flat surface with members, then laying on of your skins on this grid for the reference plane. Instead of using 2 x 4's planed, I used ripped MDF shimmed on the floor. My link shows pictures.

[Jim O'Dell]

The key is to use a flat surface as a reference. I usually use my Table Saw and side table. I have built one top that was too big to do this, and it took me 2 tries to get one that is flat. I had to build the base and a web sub-frame for the torsion top to sit on and build it flat. A pin nailer works fine. I have also used screws. Just need it to hold the wood in place while the glue dries. So far I've built 6 of varying sizes from 27" X 52" to 38" X 70". No problems with any of them, except that one I had to scrap and start over with. Jim.