I have been working on a white oak trestle table for a long time. The top sat against the wall for a few years. I finally broke it out and find that there is a crown in the center the length of the table. I was ready to cut it up, but thought I'd try to persuade it to come back some. I built a level table out of a couple sheets of 3/4 plywood which I the screwed to my heavy sawhorses. It is all level and good on the base. I laid some thin cardboard on the ply and sprayed it with water, laid the top one that. Laid waxed paper across the top and with 4- 2x2x.019 steel clamped them across the table. The table has flattened out nicely over a few days. I am leaving it in the clamps right now. I'm afraid it will explode Anyway, I achieved the goal and now, the quandary is...where do I go from here? The top is 32x74x1 1/8". It is a six board top with mahogany strips on the glue joints. Full length Wh oak splines in the joints and oak breadboard ends. Plans are good, but these things need to be thought through