Any Engineers in the house??

[Anthonyl]

Hey there, I'm wondering if there are any engineers that could have a look at my purposed stand for a 600gal plywood reef build. I'm thinking about having it built out of 2" square tubing. The 2 top longer rails will be 2"x4" tubing. Dimensions of the stand are 103"L x 31"H x 44"D. I was thinking using 8 leveling feet, just not sure on size.. Any advise is greatly appreciated thank you..

 

[jim_fitz]

flip one of the end braces
just have the feet under the verticals so six in this case

if you look on my build thread you can see mine which is a similar size, and would highly recommend having it powder coated

 

[Soren]

I second using feet only under the vertical legs. Offsetting with a different number would just increase frame stress at any feet not directly under a vertical.

I also second the powder-coat suggestion. Steel will rust quickly around saltwater, and powder-coating is one of the best options to prevent this. Of course, you could consider other materials that are less corrosive or non-corrosive, but they will likely be more complicated in design and cost more.

If you want extra security, you could consider adding triangular plate gussets in corners without braces (or replace braces with gussets on all corners). I can elaborate if needed.

Do you have a particular reason to have an internal horizontal cross-tube so near each end horizontal cross-tube? I am designing a similar frame concept for a 90-gallon reef tank right now, and I may be adding the horizontals right inside the end horizontals since the frame top and footprint is larger than the footprint of the tank to allow for a sump of the same footprint dimensions of the display tank to fit inside.

Running 2X4 square tube (with the 4" side running vertically) should be a cheap way to add insurance to the design against weight failure or warp.

 

[Anthonyl]

There is no real reason to have the cross tubes for bracing. I could go with the triangle gussets. I just over build all the time.. The reason I have the 2x4 on the flat is to accommodate the plywood for the bottom of the tank. I'm planning on building the side and back wall like you would a house to make sure there is a lot of reinforcement. my goal for inner tank dimensions are 96x40x36. I just want to make sure the stand will hold the 5k lbs. of water.

 

[Soren]

There is no real reason to have the cross tubes for bracing. I could go with the triangle gussets. I just over build all the time.. The reason I have the 2x4 on the flat is to accommodate the plywood for the bottom of the tank. I'm planning on building the side and back wall like you would a house to make sure there is a lot of reinforcement. my goal for inner tank dimensions are 96x40x36. I just want to make sure the stand will hold the 5k lbs. of water.

Overbuilding is very cheap compared to a 600-gallon reef catastrophic failure.
I would guess 2X2 tube would be enough for support based on my intuition from working as an engineer and drafter in a structural application, so using the 2X4 horizontally for extra plywood support should work.