Wood stand strangth

[Fishfinder]

Im going to be building my wood stand. I am confident with my construction abilities. But I am unsure what size wood to use. The tank is 90x26x30. Is 2x8 enough for the 90" braces?

 

[jsker]

You would be fine with 2 x 6 construction and 4 x 4 post for the legs. If you really want to get fancy with your jointery I would suggest nothing out the 4 x 4's

 

[Fishfinder]

2x6 is strong enough? Thanks for the help. How do you determine that?

 

[SashimiTurtle]

I would use something like this... 2x6 for the red and yellow boards and 2x4 for the rest. You can probably get away with one vertical center brace.

 

[Fishfinder]

My intention was to not have a center brace. Not if its not possible then I have to live with it

 

[Finhead]

IMO I would not se 4X4 posts they tend to want to warp no matter the grade you buy. Much better to laminate two 2X4's together.

 

[jsker]

2x6 is strong enough? Thanks for the help. How do you determine that?

Most of your weight is distributed on the four corners. As @Robin Haselden posted in the drawing the Pink is your support and carries the weight. You would also need the center supports. If you were not using the center supports, then it would be required you use wider stock or laminated support stock.

 

[jsker]

My intention was to not have a center brace. Not if its not possible then I have to live with it

I would suggest looking into the laminated support stock then link. That would give you the support and the openness that you are looking for. I would not suggest using pine unless it is yellow pine.

 

[Fishfinder]

The center support is the safest option. It will just make removing my sump a big pain. But I'd rather have that small problem. Thank you for the help. @Robin Haselden is that an engineering program you have?

 

[SashimiTurtle]

The center support is the safest option. It will just make removing my sump a big pain. But I'd rather have that small problem. Thank you for the help. @Robin Haselden is that an engineering program you have?

Google images search "DIY aquarium stand plans"

 

[pdxmonkeyboy]

i have an 8 foot long stand with 2x6 horizontals and 2x4 legs. i do have a center brace in the back that is screwed to the sheeting. But on the front i just wedged a 2x4 in there. if i need to take the sump out or whatever i just take it out.

The horizontal rails are not going to break or anything, buy they will slowly bend overtime without the brace. I left it out for two weeks once and had a heck of a time getting it back in.

 

[nosmok]

I built my 150 gallon stand entirely of plywood with the exception of a center brace and some poplar facing. The sides and long structural beams are sandwiched 3/4" cabinet grade, pre primed. I glued and screwed the laminated pieces and used a 3/4" setback on the inner pieces to allow for a mitered joint. The back is another single sheet of 3/4" with large vertical slots for cables and plumbing. The top is also 3/4 plywood with holes drilled for plumbing. The unit was spray painted black on the outside and white on the inside to increase visibility when working underneath. I also used white flex seal spray to waterproof the floor of the stand (also 3/4 plywood). The unit is super strong, square and has more room inside than a conventional 2x4 frame covered with plywood.

 

[nosmok]

 

[nosmok]

 

[nosmok]

 

[nosmok]

 

[nosmok]

All plywood except face frame and center post. Sandwiched double thickness sides, glued and screwed with mitered connections to rear single sheet back. All screws from inside using Kreg pocket screws to connect side, face frame, top and bottom. Bottom of inside also sprayed with white FlexSeal to waterproof. Top was drilled with hole saw for plumbing. Super strong, rigid, and much more open underneath than 2x4 or 2x6 frame.

 

[pdxmonkeyboy]

i went steel and plywood with magnets on the newest stand

 

[don_chuwish]

I would use something like this... 2x6 for the red and yellow boards and 2x4 for the rest. You can probably get away with one vertical center brace.

I like those designs. The verticals at the corners and center are always WAY stronger than they really need to be, simply because the lumber is cheap and it's easiest to build that way.
You can actually get away with less, like mine:

I doubled the front beam out of pure paranoia and because it was kinda fun to do.
At 90" I would certainly want at least a center brace in front. They key is choosing straight kiln dried lumber and then making it even straighter in the shop. Jointing, planing, etc.