Glass thickness for size/number of gallons, etc. calculator...?

salty150

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There used to be a calculator where you could put in the size of the tank you wanted to build, etc. - and it would then tell you the minimum thickness of glass you needed, etc.

Anyone know where that is? Or?
 
AS

ISpeakForTheSeas

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Here’s the one I use, but there are a number of them out there:
 
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vtecintegra

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Keep in mind that bowing should be considered. For instance, the above calculator says a 48 x 24 x24 is ok with 1/2" glass. I had a tank that size and thickness and it bowed bad.
 

oreo54

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Keep in mind that bowing should be considered. For instance, the above calculator says a 48 x 24 x24 is ok with 1/2" glass. I had a tank that size and thickness and it bowed bad.
Odd . Most that give deflection stats say it shouldn't bow more than 0.5 mm.

I checked some vendors and one listed glass thickness on a 24" tank at approx. 3/4 not 1/2".
I checked another independent calculator and at 30" height ( height is what matters) they had 3/4" glass for the sides ( bottom thicker) but 30" is sig. deeper than 24"

Now not all glass is made equal.
That could be part of it.

Then again ...thicker than 1/2" bows >O.5 mm.
I'd ask Custom Aquariums... I just got a rimless 180 gallon 6X2X2, and they used 5/8" glass. It bows maybe 1/8 (3.18) across the front,

I'd expect some discrepancy but that is fairly large...
Ignoring tempered or low iron for the moment.

That said, being the paranoid type I'd probably eurobrace it anyways.
 
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ISpeakForTheSeas

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None of these calculators "seems" to be correct...?

96" L x 30" W x 27" H - and they all say 1/2 inch glass...?
With a safety factor of 4.2, the one I shared says 5/8 inch thick glass; the OmniCalculator one says 5/8" sides and 7/8" bottom with a safety factor of 3.8. The customaquariums link doesn't work for me.

These are minimum recommendations, though, and it may be wise to go larger if it's one of the first tanks you're making (so I'd personally go with 3/4", eurobrace it, and call it good).

Edit: to add, the one I shared still recommends 5/8" when given a safety factor of 3.8, so it does match the other one; the other one just recommends a thicker bottom to be safe.
 

oreo54

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None of these calculators "seems" to be correct...?

96" L x 30" W x 27" H - and they all say 1/2 inch glass...?
Yea those calculators have been around for ages and nobody I know if has challenged the math.
My first thought was saltwater density vs freshwater.
Not sure if this is enough of a difference.
saltwater is denser (1025 kg/m3) than fresh (1000 kg/m3),
Anyways used the above...
Side glass.. .606" (15.4mm)
Bottom 21.3mm
Maximum Deflection 0.041 side, 0.03mm bottom
Safety factor 3.8

Changing depth to 24" (610mm)
sides,bottom
12.9, 17.9
0.38, 0.28
sf 3.8

Glass calc side glass math for the geeks.. ;)
glasscalcmath.JPG
 
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oreo54

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The quality of glass also depends on the manufacturer. The tensile strength varies from 19.3 to 28.4 megapascals depending on how the glass was produced. Because of this, a safety factor of 3.8 is used to measure the thickness of the glass.
Who would be surprised if the quality of the glass is worse nowadays...raise your hand.

:)
 

Sean Clark

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salty150

salty150

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That was really my main concern - the size of the Euro-brace...

3/4" glass all around - and a 3/4" single piece (hole cut out in the middle) 4" perimeter Euro-brace...

It appears that the big tank manufactures (Red Sea, Waterbox) put the Euro-brace inside the tank...

Isn't that a lot of weight for just some silicone to hold...?

Seems like it would be more appropriate to have the Euro-brace on the top and not inside...?
 

oreo54

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That was really my main concern - the size of the Euro-brace...

3/4" glass all around - and a 3/4" single piece (hole cut out in the middle) 4" perimeter Euro-brace...

It appears that the big tank manufactures (Red Sea, Waterbox) put the Euro-brace inside the tank...

Isn't that a lot of weight for just some silicone to hold...?

Seems like it would be more appropriate to have the Euro-brace on the top and not inside...?
Well don't hold me to this but in general tension strength is stronger than sheer strength.
Remember the old super super glue commercials where they picked the guy up wit a hard hat glued to something.
Strong right? Take a hammer and tap. the side of the hat and it will fall right off.
So I was told.

The silicone in between the glass panes vs the angular bead on the outside. Same thing.
Once the silicone is cured, it will show minimal changes in elasticity with ultimate elongation peaking at 513% and a tensile strength capable of withstanding up to 480 psi.
 

FSP

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- Glass is metric, so 1/2"=12mm, 3/8"=9mm (sometimes 10mm) and so on. Matters somewhat.
- A lot of calculators give minimum thickness for framed (not euro) aquariums with cross bracing. Eurobracing should go up a tick or two, rimless a few ticks.
- Calculators don't account for build quality.
- Weakest part of silicone that needs to be accounted for is peel strength. If it's not listed, it usually isn't worth using.
- Doesn't really matter where the euro goes. One piece is big $$$ time with a water jet though.
- Bottom will need a brace too unless thick enough with sides built around it.
 
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oreo54

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None of them refer to frames or braces. .https://www.omnicalculator.com/other/aquarium-glass-thickness

A center brace basically splits your tank into 2.
Measure any Petco braced tank and the glass will be thinner than any calculated " braceless" tank.
24*24*24 calculated to .34" side glass.
48*24*24 ....47 side glass

Again silicone sheer vs tensile strength matters.
The seam strength comes from the bond between the glass panels. Not the smear on the inside of the seams...........Structurally the "Euro brace" placed on top is nearly useless except to prevent water splashing out of the tank.

Real Euro brace is placed on the inside of the glass - its that simple.

And .

If you want to use a thinner glass to keep your costs down and still maintain an acceptable safety factor, you can simply design your tank as if it were two tanks by installing a front-to-back brace across the top/center of the tank. This effectively turns a 4-foot long tank into two 2-foot long tanks by supporting the top center of the front and back panes of glass.
 
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FSP

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True, the calculator just spits out a number. It's on the builder to know what it means.

Look at the peel strength of silicones confident enough to list it. It's the weakest link and will be a problem before sheer or tensile. Build quality will be a problem before any of those.

The quote about eurobracing is nonsense, and the quote about crossbracing is overgeneralized to the point of also being nonsense.
 
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