Is a 2x6 enough for the top span on a 120 gal so that it can have no center brace?

[Roland Jacques]

Helloo, "2 x 10 to get a safety" that crazy.

im sure he a good guy, but your engineer friend has NO CLUE when it comes to glass Aquariums.

SRC has it right on the money.

just put foam under your tank to distrubute the load evenly and relieve pressure points. (white low density foam) safety factor 9. ask your engineer friend about that.

The foam will make up for common irregularity of wood, that gose for the crown of the wood also.

The reason most aquariums break is pressure points (like a little rock under the molding when you sat it in the stand) and deficits in the cut or glass. You can have your tank setting on 4ea 2x12 it will make on deference. Its wood, it wont be perfectly flat and nether will your tank. Glass on edge carries the weight.



ChemE Awesome stand

 

[ChemE]

<a href=showthread.php?s=&postid=6910813#post6910813 target=_blank>Originally posted</a> by yourfishman
ChemE Awesome stand

Its not mine, its marino420td's. My DIY stand looks better than most on here but it isn't better than marino's.

 

[samtheman]

<a href=showthread.php?s=&postid=6910813#post6910813 target=_blank>Originally posted</a> by yourfishman
Helloo, "2 x 10 to get a safety" that crazy.

im sure he a good guy, but your engineer friend has NO CLUE when it comes to glass Aquariums.

SRC has it right on the money.

just put foam under your tank to distrubute the load evenly and relieve pressure points. (white low density foam) safety factor 9. ask your engineer friend about that.

The foam will make up for common irregularity of wood, that gose for the crown of the wood also.

The reason most aquariums break is pressure points (like a little rock under the molding when you sat it in the stand) and deficits in the cut or glass. You can have your tank setting on 4ea 2x12 it will make on deference. Its wood, it wont be perfectly flat and nether will your tank. Glass on edge carries the weight.



ChemE Awesome stand

What kind of study determined what caused most aquariums to break? Where do you get your data?

 

[HippieSmell]

<a href=showthread.php?s=&postid=6908971#post6908971 target=_blank>Originally posted</a> by Fl_seagull
I just am starting a stand for a 120 gal tank (60"L x 18"D x 26"H). I want 4 1/2 ft free span to permit using a 75 gal as a sump.

I talked to my Structural Engineer friend and he calculated the 2ea 2x6 would give me 0.02" deflection but almost no safety factor. His recommendation was to use 2 x 10 to get a safety factor of 5. He also recommended 3/4" plywood top to ensure even weight distribution.

I provide this information to provide some reference point. Obviously the shorter tank translates to a shorter span and thus the 2x6 may provide sufficient support. Attaching facing material and bring the outer support inboard also improves the safety factor. As pointed out, oak has better properties than pine.

Thanks. Do they make oak 2x6's? I suppose I could glue 2 oak 1x6's together. I would rather over build my stand than save $30 and always worry.

 

[Roland Jacques]

<a href=showthread.php?s=&postid=6912095#post6912095 target=_blank>Originally posted</a> by samtheman
What kind of study determined what caused most aquariums to break? Where do you get your data?

No study just what I saw. I was a distributor of aquariums for an aquarium manufacture for 2 years, selling and warranting over 200 large tanks during that time. Not to mention owning a retail aquarium store for 8 years. When and if a tank broke it cost me time and or money, so I can say I graduated from the school of hard knock.

I have also installed over 40 extra large aquariums. The 450 gallon im doing right now is suspended between two big pillars. Nothing under it but three 9ââ"šÂ¬Ã¢"žÂ¢ long steel Ã"šÃ‚¼Ã¢â"šÂ¬Ã‚ 3ââ"šÂ¬Ã‚x 3ââ"šÂ¬Ã‚ and a sheet of plywood. The coolest was a 400 that sat on two small pillars with a footprint of 12ââ"šÂ¬Ã‚x 16ââ"šÂ¬Ã‚ no other support. I will try and find a photo.

But it still just my opinion

 

[Drake1]

mmm so if you have a bad pressure point somewhere on the side of your tank stand how long would it take to form a crack or cause the tank to fail..would it be right away or take a few years? Also i thought pine woud be best in making a home made stand since the pine would bow and crush easlier then oak would to make itself flat to the tank
jeff

 

[Roland Jacques]

<a href=showthread.php?s=&postid=6914008#post6914008 target=_blank>Originally posted</a> by Drake1
mmm so if you have a bad pressure point somewhere on the side of your tank stand how long would it take to form a crack or cause the tank to fail..would it be right away or take a few years?
jeff

The crystal ball thread is in a deferent forum.

 

[Drake1]

thats a great response...what was the point of typing it? my only question was do they fail right away or does it take time...not sure what your response was supposed to prove...and why would i want to bust my 125 gallon tank?

 

[Roland Jacques]

Sorry man I misunderstood you. Theirs is no way to tell when a tank will brake.

No I donââ"šÂ¬Ã¢"žÂ¢t want anybodyââ"šÂ¬Ã¢"žÂ¢s tank to bust. again, sorry
I thought you were being sarcastic.

and about 80% of the stands sold are pine. pine is fine.
:mixed: :mixed:

 

[bassnman11]

There is really no reason to have a stand that is not flat on top. Put a low frame around it, level the stand, and pour on a coat of fiberglass resin. If you thin it slightly, it will flow out and be flat, with the bonus of being waterproof.

 

[Fl_seagull]

<a href=showthread.php?s=&postid=6910813#post6910813 target=_blank>Originally posted</a> by yourfishman
Helloo, "2 x 10 to get a safety" that crazy.

im sure he a good guy, but your engineer friend has NO CLUE when it comes to glass Aquariums....

I agree he has no clue about aquariums.

However, wood is a material which is not consistant even in a give piece of timber, has hiidden defects, and changes properties with time, humidity and loading.

For my stand, using 2x10 will not cause a problem since it will be 40+ inches tall to begin with.

I simple want to throw in one structural engineers evaluation in to this discussion.

 

[HippieSmell]

<a href=showthread.php?s=&postid=6910813#post6910813 target=_blank>Originally posted</a> by yourfishman

just put foam under your tank to distrubute the load evenly and relieve pressure points. (white low density foam) safety factor 9. ask your engineer friend about that.

The foam will make up for common irregularity of wood, that gose for the crown of the wood also.

The reason most aquariums break is pressure points (like a little rock under the molding when you sat it in the stand) and deficits in the cut or glass. You can have your tank setting on 4ea 2x12 it will make on deference. Its wood, it wont be perfectly flat and nether will your tank. Glass on edge carries the weight.

So if there is foam under the tank it will give you a safety factor of 9? I thought foam was just for acrylic, but dang, if it gives a sf of 9 then I'll do it.

 

[Fl_seagull]

<a href=showthread.php?s=&postid=6912536#post6912536 target=_blank>Originally posted</a> by HippieSmell
Thanks. Do they make oak 2x6's? I suppose I could glue 2 oak 1x6's together. I would rather over build my stand than save $30 and always worry.

Since my stand will have the 2x10 supported at the ends and yours will be a foot shorter you have already increased the safety factor. Both marino420td an kaboord decreased the span even more by their design. Considering many of the tanks are using safety factors of ~1.2. You would likely find pine 2x6 ok.

All the calculations are based on even distribution of weight. Yourfishman understands this well. Even if he doesn't understand that "low-density foam" does not increase the safety factor since it has little or no structural capability.

 

[Roland Jacques]

The safety factor 9 was sarcasm. Ill is more careful with that in the future. I did not conceder you guys who the in earthquake areas the safety factor is very relevant to you

Just watch out for uneven distribution of weight. Even a nickel or a knot under the trim can be bad news.

 

[Fl_seagull]

I apologize for being flippant.

 

[bagedtaco]

i have a stand like that. here are some pics

here's the tank after 2 months of running... this pic was take'n 3-7-06

the tank is 60"x24.5"x24.5"

 

[HippieSmell]

Ok, so pine 2x6's, with a span of 38 inches, and plywood on top that is smooth with no knots should be a safe stand? Should I use 3/4" ply, or can I use 1/2"?

 

[Fl_seagull]

2x6s will be fine.

The plywood is just to spread the load evenly across the 2x6. I have been advised to use 3/4". However, this is not a hard requirement. 3/4" plywood is used to bridge variations in the 2x6s and insure even loading of the two 2x6s. The design of most stand make even loading almost a given and even 1/2" plywoad is enough to bridge the gaps.

 

[drparker]

Use two smaller boards with the grain running at different angles, glue them together. This will give you much more strength and less warping than a single board. And a hard wood not pine.

Drew