I am using a 2 1/2 gallon weed sprayer tank (new of course without the
chemicals),  that you can pressurize by pumping. I put a shower head on the
end of the new 7ft hose, put it on the stove for 5 minutes and I have hot
pressure shower. Total cost $40.00. Similar to the Zodi
http://www.zodi.com/web-content/Consumer/zodiextremeshower.html
Plus its painted black and it is a good solar collector.

Gary
82 Westy 1.9TD (vegivan)