I have been trying to figure out a way to build a large (30 X 80) building table that would be extremely flat, very strong, and still be light enough to pick up and lean against the wall or put in the garage. I have very little room in my basement at the moment, and I need the table to be out of the way when I am not using it.

I'm not getting any younger, and it must be light enough for me to lift and carry. The others I have seen are waay too much at 150+ pounds.

To top it all off, it needs to be easy to build, as I am essentially lazy about things like this.

I have seen the Torsion box designs that are shown on the DYN website, but they assume you are making this a permanent addition to youur shop space. It is heavy, but still a wonderful table. However, I doubt that any of our mocels would reach into the hundreds of pounds the the DYN table is built to withstand. We need the stiffness, not the weight or complexity.

A person could build one out of 1/2 inch and 1/4 inch ply that is in the area of 36 lbs, (I made a design of it). Unfortunately, it is rather complicated to build, and requires a lot of carefull planning and work and a GOOD table saw and blades.

Suprisingly, the design I came up with consists of using hollow core doors. Hollow core doors are high technology torsion boxes all on their own. The three main problems with using them as a worktable is:

1, They do not have a very stiff or even flat surface. The skins are typically 1/8 mahogany (luan) or birch. The interior of the door is honeycomb resin impregnated cardboard. This allows some fles to the surface when pressure is applied to a small area. The surface is able to flex from one side of the center line of the door to the other, but still staying the same thickness. This creates a uneven surface.

2. Used as a table, they will eventually warp. The doors are designed to operate in a vertical position. The honeycomb size is rather large, as all it has to do is support the skin and no other weight. The Thickness of the door is typically 1 3/8, Which is not a very large web to withstand loads, considering the span. Even leaning them against a wall will warp them as the seasons and humidity change.

3. They are already warped slightly by the time you get it at the store.


I found a solution that works so far. I have successfully glued two hollow core doors together and have a VERY flat surface to build on. These will be skinned top and bottom with 1/4 birch plywood, and then the entire thing banded with Oak. The birch ply will add stiffness to the top. and add skin stiffness.

As I do not have a vacuum bag system, The glue I used needed to be strong, waterproof, and have no water in it. Water in the glue migrates into the wood, and could create a warp on drying. It also needed to be fast and require no clamping. Contact cement was the glue of choice.


At this stage, only the Doors have been glued, with the skins going on tonight. As it is, the doors are flat. Very flat. The combination is extremely strong and stiff. After it is skinned and banded, I will suspend it at the ends and place weights in the middle to see what the deflection is. I will also weigh the entire thing. That will tell me if this is a success.

The support system that I used for building was nothing more than a couple of sawhorses and 2 X 4 's.

Pictures and a complete build sequence of events will follow over the next few days.