Originally Posted by -cycosis-
Ok. So lets say you have a brand new rectangular polyethylene tank that is rated for potable water. If its your grey water tank, you are attaching 1.5" pvc plumbing piping to it. Whats the process? Drill out of 1.5" hole then attach a slip fitting? How do you mate the two pieces so that they are strong and water tight?
When I bought brand new tanks I simply told the tank manufacturer where to place the connections for the various inlets, vents & drains for each tank and they installed a fitting in each location that I could glue PVC or ABS pipe to.
I am not certain what the fitting material was. I believe that it was "welded" in using a hot air plastic welder as you cannot effectively glue poly tanks.
For DIY I would look at "spin weld" fittings or MAYBE Uniseals. I have used Uniseals very effectively in poly tanks in stationary applications. I have not tried them in a mobile application.
I am looking at 55 gallon poly drums and spinweld for my next bus.
Uniseal: Uniseal - Bulk Reef Supply
One warning: Do not use them in thin walled containers. The website says that you can use them on buckets and trash cans. I tried this and 18 of 18 failed. On heavier material they work fantastic.
Spinweld: Spin Weld Fittings
I have not used these yet but have heard of good success in RV applications.