Originally Posted by
bracebldrs
hey phixer,may be a dumd question but when an acrylic tank gets so big
does it require any type of metal framing?
Not dumb at all, it really depends on how many sides of the tank are acrylic. Most acrylic tanks derive a great deal of strength from the top panel, the access holes are normally cut from a single sheet with gradually radiused corners, sharp edges tend to propagate cracks, a gradual radius will spread the force more evenly. The thickness of the top panel is instrumental in providing a great deal of support to the sides and actually helps to minimize bowing providing the sides are thick enough for the height.
The great thing about acrylic is that it is very structurally predictable and will almost always give signs of fatigue before failure. Glass will bow very little before it fails suddenly and catastrophically. Framing is very important for a glass tank.
The tanks at Seaworld and Scripps are often open at the top for access, more of a concrete pool with a viewing window. Scripps has one that is 12FT tall and at least that long, it has one viewing window with an open top. The viewing panel is 12" thick. This particular tank is concrete and the viewing window is placed against a steel reinforced concrete frame.
Sorry for the long reply, hope this helps.