This is my melamine 41Qt 9 slot rack. I use a strip of 11" flexwatt on the back right side, and it has been running for me for a good long while! ( t-stat too! )

Im going to be getting rid of it soon, probably. but it was really easy to make, IF you have all the tools available to you.

The sides have slots for each shelf dadoed out, and then each shelf was hammered into place, and there are screws in every other shelf going up.

Works well, but i prefer plastic racks, as this thing is just WAY too heavy to move!