I am building an 8'x3'x3' tank out of medical grade stainless fro the back, bottom and sides. The front viewing panels will be acrylic and the frame will be made out of 2"x2"x1/2" stainless angle iron. <Yes, i know this will be heavy>. My question is this, if I do a center brace, can I use 1/2" acrylic safely?
Calling all big tank builders, acrylic thickness question
- Thread starter msjinkzd
- Start date
By center brace, do you mean a vertical brace, or just across the top horizontally? If you're talking about a vertical brace then I think using .50 acrylic would be borderline safe. (for two four foot spans)
Doing it horizontally, my opinion is that .50 would be too thin.
The frame will have a lot to do with the safety factor too. If you're going to use thin enough acrylic that it'll depend on the strength of the frame, then that frame must be solid. If you go with thick enough acrylic it'll add structural reinforcement itself.
Another issue I would consider, the smaller the sealing surface versus the amount of bowing that will be going on. Thinner acrylic will bow more, which will put more stress on its seals, and the thinner the seals (like the 2inches or less that you'll have) the higher chance of one failing.
Doing it horizontally, my opinion is that .50 would be too thin.
The frame will have a lot to do with the safety factor too. If you're going to use thin enough acrylic that it'll depend on the strength of the frame, then that frame must be solid. If you go with thick enough acrylic it'll add structural reinforcement itself.
Another issue I would consider, the smaller the sealing surface versus the amount of bowing that will be going on. Thinner acrylic will bow more, which will put more stress on its seals, and the thinner the seals (like the 2inches or less that you'll have) the higher chance of one failing.
I was talking about a vertical brace. Thanks for the input. We are going to tap through the angle iron into the acrylic along the top, bottom and sides with stainless bolts as well. i can get either thickness of acrylic, I just can obvioulsy get 1/2" for much cheaper than 3/4" for a 4'x8' sheet.
me too! 
i am super stoked, just have to buy the acrylic and the stainless angel and I have all the materials amassed. Alos, we are tig welding alternating spots around the entire frame to prevent warping then will seal over the eventual completed weld with silicon. It will have a custom pedestal type steel stand as well which will match my new 18'x8' racks I am putting in. soon this fish room will be pimpin'!
i am super stoked, just have to buy the acrylic and the stainless angel and I have all the materials amassed. Alos, we are tig welding alternating spots around the entire frame to prevent warping then will seal over the eventual completed weld with silicon. It will have a custom pedestal type steel stand as well which will match my new 18'x8' racks I am putting in. soon this fish room will be pimpin'!
msjinkzd;3460405; said:
Based on the link below, This manufacturer would recommend 1.5" acrylic even on a closed top setup with a 36" height. I have validated some number and have the math behind them and it seems pretty close. I came up with 1.39". We talked about it on the link below. Overall, the safety factor is the big issue that you would want to deal with. Give me a shout if you want more info.
There will be contradictions for sure, because I have even seen acrylic tank of that size with 3/4" acrylic. But it all boils down to what you are comfortable with.
http://www.sdplastics.com/aquaria1.html
http://www.monsterfishkeepers.com/forums/showthread.php?t=170977
i would be willing to make the tank less tall. Would reducing it to 2.5' tall make much of a difference? I cannot feasibly get 1.5" thick acrylic.
I guess what I am not sure of based on that information, which seems to be for all acrylic tanks (this one will be sheet stainless on 4 sides, just with viewing panels), is how thick it needs to be for MY application. I am not making an acrylic tank, i guess it would be a little more comparable to a plywood build, but steel and plywood are very different. When I called my acrylic company, they said 3/4" without a center vertical brace in the front (would be one over the top regardless).
I guess what I am not sure of based on that information, which seems to be for all acrylic tanks (this one will be sheet stainless on 4 sides, just with viewing panels), is how thick it needs to be for MY application. I am not making an acrylic tank, i guess it would be a little more comparable to a plywood build, but steel and plywood are very different. When I called my acrylic company, they said 3/4" without a center vertical brace in the front (would be one over the top regardless).
Per our phone conversation, the hard part of this would be to figure the reduction in deflection that stainless bracing would help with.
With a 2" overlap:
Would drop down to 1.32". Not much of a difference, but something to consider.
With a center brace. (basically now a 4' tank):
Comes out to 1.02"
Keep in mind all of these figures are based off of a tank with bonded corners and a euro bracing around the top. The stainless would no doubt add a bit of support.
I think you could get away with 3/4" acrylic. You might try it without the center brace and see what type of bowing that you have. From there you can add the brace if necessary. Or, you could just add the brace and be safe about it.
With a 2" overlap:
Would drop down to 1.32". Not much of a difference, but something to consider.
With a center brace. (basically now a 4' tank):
Comes out to 1.02"
Keep in mind all of these figures are based off of a tank with bonded corners and a euro bracing around the top. The stainless would no doubt add a bit of support.
I think you could get away with 3/4" acrylic. You might try it without the center brace and see what type of bowing that you have. From there you can add the brace if necessary. Or, you could just add the brace and be safe about it.