Quick "stand" question
- Thread starter the big kahuna
- Start date
Make sure the plywood is very thick or it may bow won where it is not supported, and that could cause the tank to crack. Tanks don't need as much support as people often think but, it does need to be around the edge, instead of in the middle, or the glass will crack.
You basically have a cantilever of 10% of your tank (2" out of 18", or roughly 75 lbs.) Some type of wood board underneath will help transfer some of the load from directly under the tank to the stand if it's thick enough. Obviously, there is a point where it's out too far and I don't have the structural skill to know if that will work. I would be much more positive if it was 2" on the sides since that would be (2" of of 48" and around 30 lbs), but I'm sure in practice people have done what you are suggesting and not had leaks or cracks.
The stand itself is an issue if it wasn't designed for that amount of load. Very, very sturdy sounds like an eyeball test. There have been structures with tens of tons of support that collapsed because the structure was extremely strong but not strong enough for the load.
A few issues in judging whether a potentially undersized stand is being used are:
1) the stand must have zero or almost zero movement along all 4 sides when under stress and must be capable of doing so for months or years (Any movement at all under even light stress of say 200 lbs is a bad sign)
2) the sides must start out as very close to or exactly perpendicular to the top of the stand and to the floor (any significant deviation from 90 degrees will enlarge under severe stress)
3) the legs / sides of the stand must not have defects or cracks (basically, visual examination is the only option)
4) the fasteners must be adequate for the load, sufficient in quantity and properly installed (nothing should be stripped or missing. Nails are far worse than screws, assuming the same mass. Screws should be sufficiently long and of the right type.)
Wood is very strong on compression (e.g., pushing down), but not in torsion (bending.) And bolts, brackets, screws, fasteners that were designed to maintain structural stability for let's say, 400 pounds may fail under 750 pounds. Indeed, even if they do not fail right away they may fail after a long period (6-12 months), because wood under torsion loses strength over the course of many months or up to a year or more.
I would double check with an accurate level whether the stand is perpendicular as needed and examine the fasteners to make sure they are in good shape, properly installed and adequately sized.
get some 2x4s and L brackets; reinforce the stand/shelf in the back and inside then it should be ok.
