Need to be tempered? No. It would be fine without, but the glass would have to be thicker. You wouldn't be able to drill a tempered tank.
Glass/Acrylic Thickness Calculations
- Thread starter Pharaoh
- Start date
I totally forgot about the tempered part. Nice catch Clay. I wouldn't use tempered.
The whole bottom thickness vs side thickness debate hinges on how you will support the bottom. Most people build them with the same thickness for both the sides and the bottom. But like I said, it depends.
The whole bottom thickness vs side thickness debate hinges on how you will support the bottom. Most people build them with the same thickness for both the sides and the bottom. But like I said, it depends.
Thanks to both of you! Think I'll price it at 5/8" for the bottom plate, do the rest at 1/2". Do you recommend building it with the bottom plate under the sides or surrounded by them (kind of a floating bottom)? I've see a few arguments either way.
You can do it either way, both will work just fine. Go with what you find to be easier to build.
I'm thinking about the idea of building a fish tank out of cinder blocks and might have tracked down standard sized four by eight sheet of acrylic sheet from a company that is two inches thick. I plan to make the viewing window as a wide as the sheet and about four to five feet twep.
I still have some questions regarding glass strength calculations. If I've overlooked something obvious in the preceding links/discussions you'll have to forgive me.
Firstly, do the calculators at the top assume a framed or frameless top? I'm assuming frameless and if you were to put in a frame/central brace it would adjust the span you would use accordingly?
Either way, what I am looking to do is build a paludarium with a single, fixed pane of glass on the front (access will be gained from the back). Now, if the above calculators assume a frameless top, it follows that I can use them in the calculation since the additional glass on top would only serve to reduce flex in the overall piece. If, however, the calculators assume a central brace or frame, how do I adjust my calculations to accommodate for the lack of frame?
Furthermore, since the glass will be braced around the entire perimeter, can I use that fact to reduce the overall thickness needed? If I'm spanning 8' in width but my glass is only 4' tall and my water is at 18", can the added rigidity provided by the overall frame be used to reduce the glass thickness in a predictable way? If so, what calculations are involved?
Cheers,
Dave
Firstly, do the calculators at the top assume a framed or frameless top? I'm assuming frameless and if you were to put in a frame/central brace it would adjust the span you would use accordingly?
Either way, what I am looking to do is build a paludarium with a single, fixed pane of glass on the front (access will be gained from the back). Now, if the above calculators assume a frameless top, it follows that I can use them in the calculation since the additional glass on top would only serve to reduce flex in the overall piece. If, however, the calculators assume a central brace or frame, how do I adjust my calculations to accommodate for the lack of frame?
Furthermore, since the glass will be braced around the entire perimeter, can I use that fact to reduce the overall thickness needed? If I'm spanning 8' in width but my glass is only 4' tall and my water is at 18", can the added rigidity provided by the overall frame be used to reduce the glass thickness in a predictable way? If so, what calculations are involved?
Cheers,
Dave
All of the calculations that I use assume that you will have a frame to support the glass. The deflection calculations are typically based on a fully supported glass pane.
The typical safety factor for aquariums is 3.8. If you add additional/stronger bracing you could effectively use thinner glass, but there is no dead set calculation for it as there are many ways in which to brace a tank.
The only way to really reduce the the glass thickness is to add additional bracing to the front of the glass to prevent the deflection. An example of this would be splitting the panes with a vertical support in the center.
I'm not saying that the 3.8 safety factor is the bottom line, but any time you go below it, there are risks. One of the things that the calculator factors for is the quality of the glass. There is no way to know what type of glass someone is using and imperfections can lead to failure. There can be imperfections in high quality glass as well. It all boils down to what you are comfortable with.
The typical safety factor for aquariums is 3.8. If you add additional/stronger bracing you could effectively use thinner glass, but there is no dead set calculation for it as there are many ways in which to brace a tank.
The only way to really reduce the the glass thickness is to add additional bracing to the front of the glass to prevent the deflection. An example of this would be splitting the panes with a vertical support in the center.
I'm not saying that the 3.8 safety factor is the bottom line, but any time you go below it, there are risks. One of the things that the calculator factors for is the quality of the glass. There is no way to know what type of glass someone is using and imperfections can lead to failure. There can be imperfections in high quality glass as well. It all boils down to what you are comfortable with.
So how do you deal with an increased vertical span between horizontal braces without increasing the depth of the water? As an example, if I'm spanning 8' with 18" of water, I might get away with 1/4" but realistically I'd go with 3/8" Now say I have the same horizontal span and same 18" of water but now I increase my glass to 4' high supported around the perimeter. Presumably the safety factor would now be better than a piece of glass unsupported at the top but worse than the original situation where that top brace was at the 18" mark. What is the math behind the charts?Pharaoh;4559795; said:
Cheers,
Dave
