Glass Thickness Guide
- Thread starter amehel0
- Start date
Because it's not using the same formula for each size. 10mm only has a 2.29 safety factor on a tank that size. IMO it's incorrect thus the reason I created the calculator to help people answer the questions for themselves.
Glass and Acrylic Calculator (Guide not Gospel)
Glass and Acrylic Calculator (Guide not Gospel)
From what I've learned, it's not so much the length or width that has a factor in the glass width but the height. Therefore the 96" is kinda irrelavant.redtailshark1;3643842; said:
redtailshark1;3643842; said:
so does the 96x24x28 tall. thats almost 280 gallons.
but its all about the bracing according to the poster who started this topic.
my 65g tank is 10mm glass with one plastic brace... a 280g with the same glass thickness must have some serious bracing to be safe.
I am in full agreement with 12 volt man, this should not be a sticky. 12 volt has stated the reasons quite clearly. Endorsing builds that are below a 2 safety factor seems ridiculous to me. Having it posted as solid numbers without details regarding bracing or for that matter the safety rating once built makes it seem as though it's fail proof. I call bs on that and here is why:
I'm quoting openly here:
"as a general it does but ply wood tanks have an advantage because it can be 4' high but if the vieing window is 2' high then its only classed as a 2' high tank(plus a lil extra for safety). with tempered glass sometimes the strength is increased by 5 times sumtimes strength isnt increased, so by all means use tempered just dont really on it being stronger."
This is in fact wrong. If the water depth is 4 feet and the viewing window starts from the deepest point and is only 2 feet high it still needs to be the same thickness as if it were 4 feet high. Why? Because the pressure at 4 feet is the same regardless of the size of the window. However, if this were written to state that the viewing window started from the top then generally it would be correct.
"ok literage has nothing to do with glass thickness, glass does not break easily unless placed under pin point pressure, i can make a 8x2x28" tank out of 10mm which will have more litres then a 4x2x3 yet one requires 10 and the other 12mm glass"
The first broad statement is false. While in general focused pressure is more likely to cause failure, the statement is misleading. Pressure over a large surface such as that of an aquarium creates a load in the pane, that load is transfered to the center point or point of least resistance. This is the exact reason for the safety factor in glass as well as the reasoning for bracing. Bracing reduces the pressure on the pane by redistributing the force to multiple points. For example 1 brace would divide the pressure essentially between two spots, 2 between 3 and so on. Now this isn't the whole story either because a brace only addresses one focus of the pressure thus is not the absolute answer for building tanks with thin panes. A brace does not support the entire pane.
"we consider our sizes as bare minimum."
That statement right there is enough for me to state that the thread should not be a sticky. To further illustrate that point:
"Quote:
Originally Posted by amehel0
well i think after 36,000 tanks we would know if the tanks were underbuilt. they have way more bracing then the crappy american tanks! theese are a commercial company and have produced many tanks. ive seen many photos of american tanks and 9/10 there underbraced and underbuilt. you use crappy silicone and plastic bracing.
but you are giving recommendations for glass thickness to people without access to your "better" silicone and "better" bracing to build their own tanks.
which is a disaster waiting to happen for someone who uses this guide without the proper bracing and 'better silicone'..
hence, why this thread should not be a sticky."
The thread advocates the bare minimum standards. Nowhere is it discussed how to brace, why to brace, when to brace, where to brace, etc.... The OP talks out of both sides of his mouth, one time stating that he uses only high quality glass and the next stating that cheaper is better so why get thicker glass for more safety when the minimum will do.
I realize that if you calculated each build here and assumed that a brace worked as full panel support, that these builds have a minimum safety factor of 2. But, braces do no equal full pane support nor is bracing discussed here. Honestly, if people read the front page of this sticky and get their answers and begin their builds they could end up with tanks having a safety rating as low as .98. I cannot imagine advocating that.
I'm quoting openly here:
"as a general it does but ply wood tanks have an advantage because it can be 4' high but if the vieing window is 2' high then its only classed as a 2' high tank(plus a lil extra for safety). with tempered glass sometimes the strength is increased by 5 times sumtimes strength isnt increased, so by all means use tempered just dont really on it being stronger."
This is in fact wrong. If the water depth is 4 feet and the viewing window starts from the deepest point and is only 2 feet high it still needs to be the same thickness as if it were 4 feet high. Why? Because the pressure at 4 feet is the same regardless of the size of the window. However, if this were written to state that the viewing window started from the top then generally it would be correct.
"ok literage has nothing to do with glass thickness, glass does not break easily unless placed under pin point pressure, i can make a 8x2x28" tank out of 10mm which will have more litres then a 4x2x3 yet one requires 10 and the other 12mm glass"
The first broad statement is false. While in general focused pressure is more likely to cause failure, the statement is misleading. Pressure over a large surface such as that of an aquarium creates a load in the pane, that load is transfered to the center point or point of least resistance. This is the exact reason for the safety factor in glass as well as the reasoning for bracing. Bracing reduces the pressure on the pane by redistributing the force to multiple points. For example 1 brace would divide the pressure essentially between two spots, 2 between 3 and so on. Now this isn't the whole story either because a brace only addresses one focus of the pressure thus is not the absolute answer for building tanks with thin panes. A brace does not support the entire pane.
"we consider our sizes as bare minimum."
That statement right there is enough for me to state that the thread should not be a sticky. To further illustrate that point:
"Quote:
Originally Posted by amehel0
well i think after 36,000 tanks we would know if the tanks were underbuilt. they have way more bracing then the crappy american tanks! theese are a commercial company and have produced many tanks. ive seen many photos of american tanks and 9/10 there underbraced and underbuilt. you use crappy silicone and plastic bracing.
but you are giving recommendations for glass thickness to people without access to your "better" silicone and "better" bracing to build their own tanks.
which is a disaster waiting to happen for someone who uses this guide without the proper bracing and 'better silicone'..
hence, why this thread should not be a sticky."
The thread advocates the bare minimum standards. Nowhere is it discussed how to brace, why to brace, when to brace, where to brace, etc.... The OP talks out of both sides of his mouth, one time stating that he uses only high quality glass and the next stating that cheaper is better so why get thicker glass for more safety when the minimum will do.
I realize that if you calculated each build here and assumed that a brace worked as full panel support, that these builds have a minimum safety factor of 2. But, braces do no equal full pane support nor is bracing discussed here. Honestly, if people read the front page of this sticky and get their answers and begin their builds they could end up with tanks having a safety rating as low as .98. I cannot imagine advocating that.
I emailed a mod about this thread and the potential dangers to a first time builder without proper bracing but was told that the numbers are probably correct..so it remains a sticky...
I also tried to get clarification on the bracing in this thread etc. but that didn't get anywhere either.
I tried.
The panels need to be supported on all four edges. Bracing needs to be applied to the top so it doesn't bow. (I have done these calculations using the long process of paper and calculator, they are specified as if held fast at all four edges.) Allowing the top to bow outward is quite a compromise (although it can be done with thicker glass for the same margin of safety)
The numbers are only right under special circumstances such as bracing. I can easily show you with the calculator that the tanks built as they are described on page one are far from optimal. One tank, if built without bracing as one would assume reading the first page, has a safety factor of .98. I wouldn't even go that low with a fully framed plywood tank.12 Volt Man;3645271; said:
The point is, this thread is misleading and not well documented. There is a very real possibility that people are using the numbers without understanding the "entire" build. Several parts of the build are not even what I would consider safe as a diy'er, even calculating the highest possible safety factor with bracing some of these tanks are below 2.5.
I could care less if my calculator is part of the thread or stickies or whatever as long as people know it's out there and to use it along with common sense and the rest of the articles on this site to make a sound decision for themselves rather than blindly following a very misleading guide.
the thing is, I don't think that all the recommendations are risky.
eg.
36x15x18 made with 6mm is probably common here in north america with proper bracing.
but
96x24x28 made with only 10mm is unheard of with or without bracing. its tanks like this that had me concerned about this thread being a sticky..if someone see this and goes and builds a 280g tank with glass normally used on tanks 1/4 the size without proper and correct bracing it could be disasterous.
eg.
36x15x18 made with 6mm is probably common here in north america with proper bracing.
but
96x24x28 made with only 10mm is unheard of with or without bracing. its tanks like this that had me concerned about this thread being a sticky..if someone see this and goes and builds a 280g tank with glass normally used on tanks 1/4 the size without proper and correct bracing it could be disasterous.
