Need help with weight calculations build a stand [Archive]

Easttuth

07/27/2014, 09:21 PM

I have no idea how to calculate the wood needed to hold my tank. If I was to build it without the proper data I would likely over build for safety, but I'd rather have the knowledge.

Tank is 8ft by 3ft and ~500 gallons. Canopy will be virtually no weight.

I was think about using six 4x4s, one in each corner then another two in the middle. So three across the front and same on the back. A sheet of plywood framed out on top of those, padding for weight distribution and leveling, then the tank.

Sound ok?

uncleof6

07/27/2014, 10:02 PM

This tank exceeds the limits (arbitrary) for using plywood ;) However, 4 x 4s are not suitable either. 4 x 4s are simply not stable enough dimensionally for use in stands.

As far as vertical support, you need more than you are planning, and a better number is direct vertical support every two feet, using doubled 2 x 4s. (more stable than a 4 x 4.) You could use 2 x 4 for the top rim (consider the vertical support system,) though 2 x 6 won't hurt. At this point you have exceeded the strength requirements for the ~2.5 ton tank. The math will just make it all confusing. Basically, use RocketEngineers design...

Personally, I would and do use steel tubing for tanks this size, as lumber is too much trouble to work with and end up with a dead flat co-planer top, (twist, crook, and bow) that will need to be considerably more beefy than a sheet of plywood, unless it is a rimmed tank, with only the perimeter in contact with the stand.

Padding or foam, is NOT used under a tank for weight distribution, leveling or any other purpose than to alleviate point loading that can only occur when the bottom glass panel is in direct contact with the stand top...e.g. a rimless tank, and then it is ONLY used to alleviate the point loading, not to make up for shortcomings or errors in the stand construction. That said, do exactly what the builder of the tank says, not what anyone on this forum says.