210 cube glass strength question

[thriceanangel]

I have a couple of 55 gallon tanks left lying around and I was considering consolidating the glass. I have read that if the glass is thick enough to hold 21" of water, that it doesn't matter if it is 20 gallons, or 400 gallons. As long as it is 21" high, it doesn't matter. Especially if it is only 48" in the longest part. Wondering what everyone thought about building a 210 plywood cube out of the glass that is 6mm thick. Of course I would frame the edges of the glass in wood, and brace it as well.

[prugs]

You realize that you will need a X brace across the tank from both sides that can handle the stress.

[jaze36]

I haven't built one, but in reasearching the idea I came across similar information. I would think that if you did a real good job of building the plywood frame the glass could support the water pressure. The frame of ply would hold everything together and be the major support. I guess it is all what you are comfortable with I know alot of time diy stuff if over built you might be cutting it a little closer to the edge with this. Other with more first hand experience might have other ideas though.

[thriceanangel]

First hand experience is what I am after if possible, or else a physics major that would want to do the calculations. I would build a frame around each pane and fasten the panes together- wood to wood, then I would have wood go around the inside perimeter of the top (eurobracing?). I would also have 45* braces in each corner instead of going all the way across the tank. The bottom would be wood, and the back pane would be wood.

[fufi5]

You can check www.garf.org (Geothermal Aquaculture Research Foundation), go to the DIY pages section and check the tank building calculator. Shows the materials list and other details. Hope this helps.