I have been working on a design for a stand for my 20 gallon aquarium to sit on. Each side of a square is 2 inches long in my diagrams. Pocket hole joints are indicated by double arrows, while the lil box thingies are L brackets. I plan to attach the top to the legs using figure 8 brackets.
Are there obvious ways I could improve my design? This will be my first serious woodworking project.
Here are the side and top views:
I just put my finger on the problem with your design. It’s Oops: All face frames.
A face frame is a low-load structure attached to the front of a cabinet mostly for appearance. It may add some rigidity to a cabinet, it might be a mounting point for doors or something but doesn’t bear the main load of the cabinet.
If I read your drawings correctly, you’re butt jointing four face frames together into a box. 2-inch wide rails and stiles attached with pocket screws.
The problem really isn’t the lumber, it’s the joints. I bet this table would hold the weight of a fish tank…for awhile. But, if the floor isn’t perfectly level, if you lean on the tank a little while feeding the fish or changing the water, that applies a racking load to all those butt joints. Which is effectively what a pocket screw joint is; the screws really don’t add much strength beyond the glue, especially against tension and racking loads. If this thing starts leaning, the 160 pounds of water plus glass, gravel, pump, fun little castle etc. is using the length of those boards like a crowbar to pull on all those screws.
If you want to keep the construction mostly like this, what I would do is increase the board width to 3 inches, do rabbet joints on the corners, cut a rabbet in the front leg for the side leg to fit into it. That’ll eliminate the need for those corner brackets, it’ll be much less of a pain in the pants to assemble as well. And join the rails to the legs with half-lap joints, that’ll be much stronger against racking.