extruded aluminum strength

[dew2loud1]

Couple questions,
Saw some links to 8020.net, modular extruded aluminum...
I've seen a stand built out of there material for a 300 gallon that kaiden sold on here a while back and was wondering about the strength of the material. They have a deflection calculator for there products free to download on the website but I'm a biologist not an engineer and wasn't sure exactly how to use it.

The tank is 900 gallons and will weigh around 10,000 lbs

There products are just slightly above steel right now in the 2x2 and 3x3 configurations and I'm not sure if those will have enough structural stability for a tank this size.
Thanks for the help

 

[BeanAnimal]

What is the reasoning behind wanting to use this material for a tank stand? The structural elements are designed to be easily configured for complex structures and those that need frequent reconfiguration, adjustment or accessory attachment. To say the least, they are very expensive extrusions.

Why not just use welded/bolted tubular mild steel elements?

 

[NewBostonConst]

I think the extruded aluminum has a nice look. You can cut it great with a miter saw and a ragular wood carbided blade (just cut slow). The part that would worry me is the connections between the pieces, and how you would cross brace it and still have it look good. I have done alot of work with it and love the stuff.

Weight for weight aluminum has similar strength to steel, so you can see what others have done with steel and copy.

 

[BeanAnimal]

Again, it is a very expensive T-slot system designed for setups that need frequent reconfiguration, adjustment or accessory attachment. I just can't see any compelling reason to use such a system for a large aqurium.

Sure it looks cool, but I can't think of any other reason to use it for an aquarium stand. I can think of a dozen reason why not to use it though


For the same price (or actualy a lot less), you could use regular tubular aluminum extrusions and have a pro weld them for you. For a fraction of the cost you could use steel and weld it yourself (or have it welded).

 

[Harry_Fish]

I would give the vendor a call, they should be
able to give you a clear answer.

 

[kcress]

If you ask a structural person "how about extruded aluminium?" They will likely say, "NO WAY!"

Extruded anything is usually less desirable for structural stuff than plate or tube.

Personally I might use 8020 up to maybe a 55gal tank but not for 100 gallons and certainly not for 900!! My main issue with the stuff, (and I've used it a few times), is that often connections come down to a small bolt or cast part of unknown pedigree.

When supporting large heavy things you cannot have any motion between the various parts of the structure or forces occur in areas not able to resolve them suitably. When that happens you get a sudden chain of failures that leads to.. nothing good.

When you look all over that sight you will see conspicuously missing examples of large amounts of dead weight sitting on assembled 8020 structures.

I would not do what you propose even though it has its appeal.

 

[dew2loud1]

I was just curious as I saw it used on a 300 gallon about its integrity...
As far as cost believe it or not its very very close to price of steel currently within .20 a foot difference compared to 2x2 .25 wall steel. I just moved 2000 miles away and don't have any of my welding equipment with me until next year, so with the cost of 1. having someone fab up the stand and weld it and 2. having it powder coated or rhino lined I'm looking at an additional $1000 to fab up a steel stand.

It wasn't necessarily a proposal just curiosity
More than anything I was just curious as to its actual strength, making a light rail out of it would be great, but I was contemplating a stand build if it was more than adequate.

Ok,
Back to steel then
Most stands I see on here are way over built,
For 10,000 lb dead weight what is an adequate steel diameter and thickness, obviously 2x2 .25" is plenty overkill, how about 3x3 1/8" wall, or even 1.5x1.5 .1875" wall
This is assuming uprights every three feet and adequate cross and corner bracing. There will be no equipment/sump under the tank so bracing distance can be however needed for stability.

Thanks again guys

 

[kcress]

Well I certainly can understand the convenience of the 8020..

Yes most are probably overbuilt.

As for possible sizing I can't say since you haven't given dimensions.

A 3ft square 10 feet tall would need a different stand than a 20ft long 2ft wide 2ft deep tank.. :fun2:

 

[stugray]

Yeah....

Dimensions & Intentions help a bit in this forum.

If we dont know what you are doing we cant help much.

Stu

 

[dew2loud1]

sorry thought I had already mentioned that, I had but in another thread
108"x48"x36", stand probably 44"-48" tall, I plan on bolting the stand to the concrete as well.
thanks

 

[dew2loud1]

48" is the width 36" the height

 

[cdness]

yeah I'd rather be overbuilt than underbuilt... that's for sure.

 

[kcress]

Twas me.
I'd use 2x4 - 0.125 on edge for the top rectangle.

I'd use 2x2 - 0.125 for all the rest.

I'd use five uprights spread over the face. (Two uprights at the ends and three more evenly spaced in between.)

I'd run three braces across the top,(five with the ends), to prevent spreading and to evenly spread the vertical loading. Same 2x4.

If you are going to bolt to the concrete, (good plan), then you need no cross pieces at the stand bottom. Single diagonals across the two outer rear squares.

Single diagonals on the ends: 2x2

You want heavy duty? Make it all 0.250 steel. This doubles the weight and cost. But would support any stray locomotives that might land on it.

 

[Kahuna]

I know that this is a really old post, but there's a lot of inaccurate assumptions regarding extruded aluminum. We use it in many parts of equipment that handle large loads and reprocating mass without issue. I'm currently studying using extruded aluminum for a 300DD stand using 8080 and 8040 with 8040 gussets. These are not slotted connections and T-bolts, but machined carbon steel inserts that are pocketed into the mating parts and firmly joined with grade 8 hardware. Price is $400 and will go through my front door, whereas a 36 X 38 X 72 welded stand will not, and that is the real advantage to using this material.

Kev