Hold down fixtures (material to use)

[BPM]

Thanks in advance!

I have a 5' x 12' vaccum table -- I place 12 fixtures along the X axis -- 12"W x 60" (Y) long.

We've been making these fixtures out of glue-ups (Alder, plywood, poplar, etc) They are 3" in height -- so you can imagine they are heavy.

We machine contours on the surface - vacuum area and a channel to run the vacuum gasket material in.

My Question: Is there a light weight (but durable) material you've come accross to build hold down fixtures?

Again, these fixtures are 12"x60"x3"

Thanks.

[gbradley]

Why so high? Do you have a picture of one of the fixtures?

[BPM]

George,

The fixture is cambered in the middle -- it's actually 2 3/4" high in the center, then curves down in both directions to 1" thick.

[donek]

sounds like you want to make a hollow particle board box with the profile cut on the edges and possibly some cross supports in the middle.