12mm tempered or 19mm???

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badar7

badar7

Feeder Fish
MFK Member
Jul 9, 2011
25
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lahore,Pakistan
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m a monster fish keeper from pakistan...i have kept gar from years....n others...m planning to make a bigger tank of about 450g...

i want to ask the experts here that is 19mm glass more strong or 12mm tempered??....btw i have planned to make this size 7.5ft*3ft*3ft...water capacity of 72 cubic feet....and 540g almost....which glass should i use ....infact tell me how much bigger tank can i make in 12mm tempered glass..??
 
A tank 2286MM x 914 MM x MM would require 22MM glass (non tempered) to have a safety factor of 3.8. That provides a deflection of .47MM. 19MM is only a safety factor of 2.6 and has a deflection of .83. So, it could work, but you have much less safety margin. If you know that the glass is excellent quality and you provide added support between the front and back to reduce deflection, it has a better chance. The eurobracing style is an example to use thinner glass.

I do not have a calculation for tempered glass. I do know that it's stronger, but it also can't take some abuse that non tempered glass can take. I can't tell you whether 12MM will work in that tank because that is quite a bit thinner. It might work and then one day it might explode, or it might last for 20 years.
 
bro plz clarify me 2 things.....1) deflection 2)safety factor.....what do they mean and how you calculate them...or any small article which clarifies them..

i will give a support between the front and the back..(2feet in center ,and 1ft 1ft on sides......on top of the aquarim,front to back)......plus a support on the base of the tank....that will run on the edges of the base in all tank....(so the grip from the base will b doubled).....

should i go for 8*3*3.....or reduce the depth to 2.5.....ie......8*2.5*3.....(feet)
 
actually the place where i live dont have any experts...or proper aquarium makers.......even the big shops dont have the concept of making a tank bigger than 175/200g......so iiii haveeee to do it myselffff....
 
My new tank is 10´x4´x28" and it was made in 15mm glass. The safety factor is 3.6
The problem with your plans is th height of the tank IMO. If you choose 3ft h you will need thicker glass. Probably 19mm at least.
If you reduce the high to 24", the thickness (hence, the cost) of glass may be reduced. Do consider that
 
badar7 said:
bro plz clarify me 2 things.....1) deflection 2)safety factor.....what do they mean and how you calculate them...or any small article which clarifies them..

i will give a support between the front and the back..(2feet in center ,and 1ft 1ft on sides......on top of the aquarim,front to back)......plus a support on the base of the tank....that will run on the edges of the base in all tank....(so the grip from the base will b doubled).....

should i go for 8*3*3.....or reduce the depth to 2.5.....ie......8*2.5*3.....(feet)
Click to expand...

Deflection: when you have a line (like the side of a tank is supposed to be in a straight line), and the line is not perfectly straight because some force is bending it, that's call deflection. The water in the tank pushes against the tank walls (harder than the air pushes back) and bends the glass. You can see this on acrylic tanks easier, but those tanks can bend and not break easier than glass tanks, because acrylic is more elastic than glass. Glass is not elastic, so it will bend a very small amount until it fractures and ruptures. Of course, you don't want glass to bend too much.

Safety factor is an estimate of the possible things than may go wrong with glass. Adding an additional amount of glass thickness can compensate for problems. If you have poor glass quality, extra thick glass makes up for some of that poor quality. If you have no support, again extra thick glass. If temperature of the tank goes up or down a lot, or you have big fish than hit the side of the tank, or kids toss a ball at the tank, or the floor is not perfectly level. All that can be made up some by thicker glass. The thinner you go, the more perfect everything else has to be or your tank fails.

Thee extra support you mention will help some on 2.6 safety factor glass especially the cross bracing and side bracing at the top. You seem to have a lot of support, so that could be enough to work. If you are not having fish to bang the tank and the glass is good new glass (not store window or old used glass), then I think that could be fine. The poorer one thing, the more other things have to make up for it. The stronger some things, the less other things have to be.

Reducing the depth will help reduce the pressure on the glass.

Going to 8 feet (long) by 2.5 feet (tall) and 3 feet (wide), so it's 30 inches high, will let you easily use 18MM glass. You should not need as much bracing either with that thickness.
 
Stay with the 3ft height if you can as it really makes a big difference to the viewing experience.
You need 19mm plate for this height and believe me when the tank is filled you,ll be glad you went for the thicker glass.
 
Rustyspurs makes a good point to consider a lot. If you can stay with 3 feet tall and 19MM thick glass, then 1) use good new glass and 2) give it good cross bracing and some side bracing. Here is an example, although there are many ways to do this.

main.php
 
Safety factor basically shows the "margin for error" in relation to the strength of your glass. It is calculated based on a well braced tank made with regular glass, and doesn't take into consideration things like defects in the glass, poorly siliconed joins, unlevel stands, etc. So a safety factor of 1 is the exact amount of weight (of water) the tank should be able to support based on the strength of the glass, anything under 1 should theoretically break. So a safety factor of 2 means the glass is twice as strong as it needs to be to support the weight. SF 3 would be three times as strong as it needs to be. It is up to you to decide how safe you build the tank, usually people aim for around 3 but I have seen much less. The height is the main factor in determining the thickness of the glass, as deeper water puts more weight on the bottom of the sides and their join to the base.

Joao M said:
If you reduce the high to 24", the thickness (hence, the cost) of glass may be reduced. Do consider that
Click to expand...

I agree, reducing the height to 30" with the 19mm will give you a safety factor of over 4, which is pretty damn good. You could build the tank somewhere between 30-36" high with the 19mm glass and have a good safety factor. Have a play around with this calculator to see what you could comfortably get away with; http://www.theaquatools.com/building-your-aquarium

I'd be inclined to go with regular glass instead of the tempered and reduce the height to 28" as Joao suggested. That would mean you could build it out of 15mm glass with a safety factor of over 3, I'm not sure of glass prices in Pakistan but I'm pretty sure that would save you a lot of money, I know it would here!
 
m going for 7.5'long * 2.5'deep * 3'high......
plzzz leave the 19mm glass :P......m going to use the 12mm tempered glass (as its weight is quite less and its cheap...and provides same strength..acc to my sources)......the problem is that m not sure about the strength of the 12mm tempered glass....if anyone knows someone who has any info about the tempered glasses ,plz share.........

Drstrangelove..david...n everyone ,thanks alot for sharing the information :)..... plz add me on facebook badar7@live.com, would love to add u guys thr

@everyone... plz suggest is the above size safe?? with those supports...alllll over the base...and on the top..front till back..
(in 12mm tempered glass)
 
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