I'm using Ed Klepies cooling frame set-up and I'm having trouble

  finding a suitable water expansion tank.  Does anyone have a

  suggestion for where I can find a suitable tank?

 

  Thanks to all for your expansive knowledge in all things rotary.

 

I'm not familiar with the Ed Klepies cooling frame set-up, and I don't know what your configuration constraints are.  There are various automotive tanks that have been used - Volkswagon, Volvo, etc.; or others from racing supply stores.

 

Or you can do what I did.  Go to your local fire extinguisher service/refill place, and check for one of their reject bottles that is about 1 1/2 quarts.  These are lightweight aluminum bottles, usually painted red.  On mine I was able to just peel the paint off, no paint remover required.  I bought a cap neck from one of the on-line specialty shops, and took it to my favorite aluminum welder for welding on to the bottle.  Result is a nice lightweight tank that was the right configuration for me (see photo).  Also installed a low-level switch.

 

Al