Originally Posted by Lookinghard
I am currently replacing the floor on my 1962
Ambassador. When I purchased the Airstream last year the prior owner had removed the waste tank and mounted the commode directly to the floor. Much of the floor needed to be replaced due to years of water damage. After much searching, for a replacement tank ( with no luck ) I decided to make a custom waste tank. I have calculated the capacity to around 20 gal. These are the photos of the tank. It fits like a glove in the corner just like the origional one. The design is slightly modified to allow for the tank to actually support the weight of the commode and whoever might be sitting on it. The tank has internal struts to support weight ( the origional tank was made of fiberglass and needed a frame around it). This one is much stronger and made of aircraft T6 aluminum.
If anyone is interested, I can give the specifics on how I made it and how much it cost. I plan on covering the tank with hard wood flooring so you wont see any of the aluminum tank when finished! It's kind of amazing what people will do to have a functional commode on the road!
This is the tank info.
Material Used 1/8 inch T6 Aluminum. 1 4' x 8' sheet.
One T6 Bar Stock Aluminum 6"x4"
4" of 2" aluminum Pipe.
Total Cost for Material $165 at Industrial Valley Metal Supply in Sum Valley CA.
The tank measures 24" wide by aproximately 42" long and is 6.5" high. As you can see there is a round curve in one corner to allow for the curve in the airstream. When I purchased the material I had the shop sher the sections into squares so all I would have to cut is the curve.
I then took everything home and cut a template from wood to make a pattern for the curve. Once I had the curve I then cut the curve into the aluminum sheets using a 14" band saw. I then sanded the curve smoth with a 12" disk sander.
I then took all parts to a machine shop in Van Nuyes Ca (I dont have the phone number but I can get it if anyone wants it) to machine the bar stock into the fluch out on the bottom of the tank. The inside of the pipe was machined with a smoth curve to allow for a good flow rate while the outside will match up to a standard 3" ABS pipe. In addition, I had one extra vent pipe(two in total) put on the other side of the tank. I also had two 1/2" female pipe sockets made and welded into the tank. I plan on plumbing in a tank flush system to allow for quick and efficient cleaning. In addition, there were four 3/4" x 6.5" of bar stock used to support the tolit flange. This took all flex out of the tank since the bar stock supports the weight and is attached to the top and bottom part of the tank. It's hard to explane but I can get a few pictures in a few weeks.
After the machine part was finished the shop welded all parts together into the finished tank. The Labor was $320 for all machining and welding. This machine shop makes aircraft parts and their work quality is very good. If an airstream could fly, I am sure I could get this tank certified by the FAA.