Glass Thickness Guide

[loogielv]

temperd may be more shatter proof but it cannot handle any bowing.

also the 8x3x2 bracing positioning is good but, i would use way thicker glass. that seems to be6mm i woulkd use 10 or 12.

well it can handle some bowing, but the idea is that it won't bow. it's 6-10x stronger than regular, so while there's one concern for an explosion of water and glass bits, its far outweighed by the strength factor and also the little thing of plate also being susceptible of an explosion of water and glass. However you will NOT get glass bits w/ plate. you will get glass shrapnel.

I'd take the slim chance of water and dead fish on the floor over the off chance that a plate glass leak will only be a slow leak, and if not, i might have dead dogs and cats...or worse.

of course, i'd take whichever i was able to get and make sure i was within reasonable safety factors EITHER way.

 

[coolkeith]

temperd may be more shatter proof but it cannot handle any bowing.

well it can handle some bowing, but the idea is that it won't bow. it's 6-10x stronger than regular.....

Sorry to say it, but you are both wrong.

Actually, tempered will bow just as much as regular glass of the same thickness. Tempered has about the same modulus of elasticity as plate glass. Tempered is 2x to 8x stronger in it's modulus of rupture and tensile strength, meaning that it will flex more before it actually breaks.

Here is a link to a pdf with the mechanical properties of both plate and tempered glass. It also has a few formula's for finding deflection, rupture loads, and crush loads of glass.
http://www.alumaxbath.com/tech/gp.pdf

Here's a wiki link to tempered glass where they explain how tempered is stronger, but it defects the same.
http://en.wikipedia.org/wiki/Toughened_glass

 

[loogielv]

what i got from the links is that deflection isn't bowing. it can deflect more, because it's stronger, but doesn't mean it bows more...guess i'm wrong, since you obviously know more about it than I do. I was just under the impression that tempered glass bows much less but can support more weight in that bow.

 

[coolkeith]

deflection is a term that is used to describe the degree to which a structural element is displaced under a load.

http://en.wikipedia.org/wiki/Deflection_(engineering
http://en.wikipedia.org/wiki/Deflection (engineering)

 

[richman]

Hi,

I appreciate your willingness to help.
I want to build a tank in my basement and i am getting conflicting sizes.
The tank is going to be 12'x3.5'x3'.
Its going to be a wooden tank so I was just wondering what size thickness glass i would need.
I can probably get a deal on acrylic but that site you posted there says it has to be 2" so i am now leaning towards glass.
I would use 3 sections with about a 4" gap between them.

Please let me know.

 

[Zev_Nz]

http://saltaquarium.about.com/cs/aquariumdiy/l/blcustomtank.htm

http://www.fnzas.org.nz/glassthickness.0.html

Sorry i repost URL cos for some reason they were cut-off during pasting ^^

Hi, just a note to say that we have re-vamped the FNZAS site, and the correct address for the Glass thickness article is now:

http://www.fnzas.org.nz/index.php?PG=glass1

There are also two pages in the Technical menu under Glass Thickness that will calculate the panel and safety factors.

 

[681tonburb]

I would like to build a ply wood tank that is going to be 8 ft x 4 ft x 4ft with 2 viewing windows one will be 44in by 44in and one will be 44in by 92 in I was figuring on a 2in all around over lap for the viewing window . I would like to know if ¾ in glass would work.
Thanks

 

[Pharaoh]

If you use two sheets of glass in lieu of one to span 10'. Would the thickness required be the same?

 

[amehel0]

^^yes^^

.
i work with glass everyday and from my observations this is what i can conclude. in long lengths (6'+) at say 8" wide tempered will bow but only slightly. then it breaks
plate how eve can tolerate bowing and reaches 2x more bowing.

the 12x3.5x3 guy if you went 3x3 you could use 15mm if you went 3.5x3 you will need 19mm.

 

[JoelB]

So, if held at the edges and pressed in the middle, how much will a 6' x 2' sheet of 10mm plate glass deflect before it breaks?