you can build a box out of plywood and you wont have a problem some angle iron on the corners will make it slide a little better too but its not necessary
what im trying to do is build a down kink... but on the top im just gonna have 2 by 4's and then im gonna put like some sheet metal on the top or somethin but im just tryin to get some ideas about what to use.
Today I just made a rail. I turned an old 8 foot bench upside down. Then I nailed two small boards across the legs and nailed a big board from end to end on the two smaller ones. After that I cut two pieces of ??1 1/2 or 2 inch pvc and bolted them side by side on top of the large board. I ended up with a sturdy, nice looking, 8 foot long rail.
dont use sheet metal it fucks your edges so bad and doesnt slide as nice. Use lexan, puckboard pvc sheet, p-tex, nylon there are soo many dif. things U can use that are better the sheet metal. PVC sheete it so cheap too.
I just built a 12 foot box, its all wood then i used 3/32 inch plexiglass for the top. I cut the plexiglass back on the sides to put angle iron made of sheet metal on as coping. The plexiglass slides great but was getting chipped up a lot on the sides without coping. To use real angle iron it would have costed $50 the sheet metal stuff was $4. The plexiglas was $32.
^^ that sounds exactly lie the box I biult today but I used Lexan and instead of coping I have a 1 inch pvc rail on each side. twelve feet long two feet tall. sittin in my living room