We decided to buy two 70 gallon water tanks. One fresh water and one grey water. We wanted to protect it from the elements so we built a box around it and lined the box with 2" foam in hopes that will prevent any freezing.
I didn't want the boxes to deteriorate while being under the bus so I researched around the web a bit and found and interesting article or two on the "poor mans fiberglass" method of weatherproofing. Basically its bed sheets from a thrift store soaked in a titebond II glue mixture. After the glue is dried another layer of titebond II is applied then finally a couple of layers of exterior paint. Sounds interesting enough, right? We have never tried this method before so we are hoping the internet is guiding us in the right direction.
Before bolting it on the bus we installed sensors on the side walls of the water tanks. The sensors are wired to a display which will be in the bus and it will provide the capacity of the tanks. I used a piece of waterproof flashing material to protect the sensor. After that was installed to both tanks I cut some superstut material to fit between the frame and the exterior of the bus. This was bolted to the floor ribs under the bus.
We used 1/2 inch all thread to act as the vertical structure for to hold the tanks in place. The thread all is bolted directly to the supestrut on both ends to secure the tanks in place. We did not re-invent the wheel on this one and copied what a lot of others have done on their builds. There is a great video on this from Woolly Mammoth over at www.diyskoolie.com If you are interested I recommend taking a look at his build.
Before securing it to the bus I cut an intake hole on the top portion of the fresh water tank and installed a pvc coupling. I lined up where it would match up to the exterior of the bus and drilled a hole for the fill valve. I ruined two large hole drill bits trying to get the whole drilled. Finally I ended up using the grinder and grinding out an octagon shape to fit the fill valve. I mirrored the same technique on the grey water for the intake portion. Below is the final result. We will install a "skirt" of some sort to hide all the bolts and hardware, but that will be down the road.