I was thinking about making something like this for my lettuce, to replace my current system while I am working out the bugs. I will perhaps use the current system later for some other ideas.. I am sure I can come up with some ideas for it. I was thinking about perhaps using a roofing cement similar to
Roof cement for $10
to use as the cement to put the plastic down.
I have a feeling this will be more than enough to build 2 of these systems since I am only wanting a thin layer of the cement to protect the plastic from the splinters of the wood.
On a side note.. I am considering making a small soil planter for a few lettuce to use as a comparison of growth to determine if hydroponics are growing resonably. This is more of a self note of progress/setbacks since I have no past experience with the plants I am currently growing.