My son does hand painted signs. In order to help him get his shop a little more organized I offered to build him a shelf for some of his paint. I haven't built shelves strictly out of only plywood before. I'll be using 3/4" pine plywood from Home Depot. I was planning on each shelf being able to handle 1-gallon cans as well as 1-quart cans stacked and also two-deep. A lot of this is paint he's used but keeping for other future jobs. I assume he'll also put full cans in it as well. I'm concerned about the shelves sagging. I had been planning on building a set of shelves with approximate dimensions of 46" tall x 36" wide x 12" deep. I'd also planned on backing this shelf with 1/4" pine plywood. Each shelf would fit into a 1/4" dado in the sides. This morning I was reading an article on popularwoodworking dot com about shelf strength. The article shows that 3/4" ply with a moderate load (25lb per running foot) should be no longer than 32" and with a heavy load (40-50lb per running foot) should be no longer than 30".
I was considering using 3/4" ply for the back rather than 1/4" ply and also using a 1/4" deep dado here to provide extra support for the 36" shelf width. This would provide some support for each shelf on three sides. Do you think this was add enough strength to prevent sagging?
I want it to be structurally strong as well so would you advise adding a 2" face frame around the exterior or do you think it should be strong enough without that?
Thoughts and other ideas on how to achieve this would be appreciated.
PS Looking around I probably should have posted this thread in one of the other forums here. It doesn't appear like I can move it. If someone wants to move it to the appropriate forum I'd understand and appreciate it.