So we are now finished with the structural components of the base. I thought I might try to add to the collective DIY knowledge here at MFK by illustrating some of the construction techniques we used in building the tank base. You definitely don't want to under-build your tank. At the same time, you can save a lot of time and money by using some basic engineering principals in your build. My friend Tuck, a master cabinet maker, and I are by no means engineers, but I think we did a good job of not over building our tank by using basic engineering principals.
The base of a tank stand (or cabinet in my case) plays the important role of distributing the weight of the tank over the floor. It is critical that the base be strong enought that it doesnt sag any under the weight of the tanks water. My tank is just under 11 feet long and will hold almost approx 2500 pounds of water. So that is alot of weight over a long span. To make a very strong span we attached a 5 in tall piece of 3/4 in plywood to our 2x8 base board. The plywood is "glued and screwed" to the 2x8. This combination is stronger than two 2x8's screwed together. In addition, we braced the end 2x8 pieces with a 2x4. We didnt use plywood since the span is only about 18 inces.
A full shot of our completed base:
Here is the corner of our base. The corners of a base need to be really strong at they will receive stress on two planes instead of just one.
More of the plywood along the long span of the base:
One of the challenges we faced is that our tank is going to be placed right over a cold air return for our heating/cooling system. So we had to put a vent onto the 2x8 span of our base. We made an arch instead of cutting a square. An arch has slightly less area than a square but is much stronger since it transfers the weight better.
Since I am building cabinets below my tank we need to have a pretty wide span between our vertical supports. Who wants to have a ton of narrow drawers to work in lots of vertical supports? At the same time we wanted our vertical supports to be as narrow as possible. So we have to be sure that our vertical supports are very strong. We accomplished this by sandwitching 2x4's between two pieces of 3/4 in 7-ply birch plywood. This setup is very similar to the engineered I-beams used in modern home construction. This combo makes for an incredibly strong vertical support. The 2x4's rest directly upon the 2x8's of our base.
A closer look of our vertical support
Next comes of support for the bottom of the tank. All of these precut pieces can make for quite a puzzle.
The frame for the bottom of the tank is 2x4's. The plywood will be screwed and glued to them.
Now we have a place for our tools until we get the tank module started. Stay tuned for the tank construction. We are currently finishing our cabinet drawers and doors.