Plywood vs. 2x2 lumber - which is stronger?

[bottomdweller_fan]

I am trying to determine if plywood or 2x2 lumber placed vertically will be stronger to keep a plastic tank that holding 350 gallons from bulging.

Please help!!

[Parachromis1]

2X2 I would be guessing, you should be more specific on how the stand is etc.

[bottomdweller_fan]

Thanks Pimpdocta.

The stand is a 3/4" piece of plywood resting on cement blocks.

[Ruadh]

I am trying to determine if plywood or 2x2 lumber placed vertically will be stronger to keep a plastic tank that holding 350 gallons from bulging.

Please help!!

Depends on what stresses you want to put on it.

Plywood is far stronger in torsion (bending) than dimensional lumber.

Were you going to brace the bottom of the stand?

If that is the case, plywood, glued and nailed on it's edge, with the proper quarter round brace would be the way I would go.

Rick

[bottomdweller_fan]

Thanks Rick. Here is a picture of my thoughts on the bracing. Can you please clarify what you mean by quarter round brace. Thanks.

[Ruadh]

Thanks Rick. Here is a picture of my thoughts on the bracing. Can you please clarify what you mean by quarter round brace. Thanks.

I see now what you're doing.

I honestly don't think I'd trust 2x2's with 3500 lbs of water, unless you were going to cover the 2x2 frame with door skin.

Quarter round is a trim piece that's 1/4 of a circle in profile. Think of a piece of dowel cut into 4 length-wise.

You wouldn't use it in the build that you describe here, I thought of a different type of brace.

Rick

[bottomdweller_fan]

Rick, would you suggest going 3/4" plywood instead then (or change the 2x2's to 2x4's?).

[Drydock]

I just built my own stand for a 210. 3/4" x2 Screwed and glued together for the sides and back that gives me 3" of support. I have 2 laminated 2x4 across the front supporting the 3/4 inch plywood top and then supported by posts between my cabinet doors. The majority of the weight is carried by the edges, not necessarily the top sheet of plywood.

I don't know if I would use 2x2 for the sides. I would be more inclined to go with structural 2x4 or 2x6

[African_Fever]

Have you filled the plastic tank with water yet to see if it is going to bow, and how much? I would think that would factor in to how much support you'll actually need to keep it straight. Are you planning on putting a glass front in the tank too?

[Ruadh]

I just thought of a couple of other things.

What kind of plastic tank is it? Is it a rubbermaid container, a lexan tank?

This thing is going to weigh over two tons when you get it set up. That is far, far too heavy for a wood floor in a house without support underneith.

Is it going into the basement?

Rick

[trixie]

Your 8 ft 2x2 on top will hold very little it will just bend.There is not much pressure at the top most is just up from the bottom about 6 in .

Edited August 29, 2008 by trixie

[bottomdweller_fan]

Thanks Rick,

I have made some changes and will be doing a plywood tank with a pond liner instead, it just seems easier.

The tank is going to be in the basement.

[Ruadh]

Thanks Rick,

I have made some changes and will be doing a plywood tank with a pond liner instead, it just seems easier.

The tank is going to be in the basement.

So, this is just a holding tank then?

You might want to consider only raising it a foot or so off the floor.

That way it will bew a lot easier to net the fish.

Rick