180G 72" 8020 fully open - what profile and WHY?

[servus]

Cant edit the thread title... so 8020 POSSIBLE, MAYBE IRON.

Looking to build a stand as in the title. I saw fully open stands, also TONS of OVERBUILT stands, with unnecessary thick profiles.

I am challenging the overbuilt stands.

My sandwich will be:
- stand
- 1.5 thick butcher block
- additional foam and things
- fish tank

Please, by all means, jump in with math and good arguments!!! I need your help in figuring out WHY a certain profile (8020 or steel) would make sense in terms of stiffness.

I did so much math in the last two week, I think I will get a PhD in structural analysis, that's why I am looking for expert opinions. What is "allowed" deflection with distributed load? What is the load over a long side? I know the whole load of the tank will be around 2500lbs. Also looking at an 80g sump under.

Thanks, maybe we will able to say at the end "this profile makes sense BECAUSE...", without involving "math" such as "it feels better" .

 

[MBinNY]

I like the 2x2” For main supports And then used
1x2 for what the tank sits on. used it on my current build and then wrapped it in epoxy coated pine.

 

[servus]

I very much like that!!! I am looking at 1x3 over the long sides, what I see in your image gives me a lot of confidence!!!

Here's what I get as deflection for the profile:

 

[servus]

...looking to have a FULL opening on one long side.

 

[Gp!]

Are you making the stand yourself? What tools do you have available?

Do you literally mean iron or perhaps structural steel tubing? Do you have relations with suppliers that make one material more cost effective than another?

You seem to have 3d drawings of what you're thinking. Are you able to analyze them yourself or are you seeking advice? Is this an educational exercise or are you going to actually build it?

 

[servus]

Making the stand myself... structural steel tubing might be the proper term: looking at 2x2, 1x1, 2x4 rectangular section, with 1/4" wall, or similar. I also took wood into account, least expensive option, yet I like the idea of a thinner frame. So far, all the extrusion and some hardware would cost me about $600 from tnutz.com.

Tools - everything I need, but a welder and welding expertise - I will have to go to a shop for that. Looking at extrusion from tnutz.com - very good prices. In terms of structural steel, not sure yet about the supply chain.

I analyze everything, being an engineer, just not a structural engineer. I read so many threads and opinions, never saw "0.100 inch per 4 feet is acceptable deflection for a tank stand", only "that's big, will definitely work" or "I would make it thicker, doesn't seem sturdy" - without arguments or numbers behind them.

I tore down a wall, and will tore another one, placing beams to support the house. The stand will be built in the next couple of weeks.

 

[RocketEngineer]

If it were mine, I would go 1.5” profile. 3x1.5 for top box and legs, 1.5 for bottom. Why? Easier to get at that size. JMO

 

[Harpo]

I'm also in the market for an 80/20 style stand. I want my legs to be large enough, so the stringers & runners (perimeter) are actually resting on top of the legs. I don't want to be testing the clamp load of any of these bolted joints