Blackwater tank
Hello all, new here and got some bad advice to keep my black water tank open constantly while hooked up at campground. Now I know otherwise. What can I do to get the contents of the tank broken up to ...
Forum Discussion
Wishbone51 wrote:Allworth wrote:
During typical winter storage, the tanks are 90% air and 10% liquid (at most).
Water expands 2.2% on freezing. Bad in a closed bottle or pipe, but...
The tank is now 97.8% (compressible) air and 12.2% ice. Even if the air were not vented through the roof, there would not be enough pressure difference to hurt the tank.
That makes sense, but I've seen an open bucket crack with a couple of inches of ice in it. Apparently it expands in all directions. This doesn't make sense to me. If it tries to expand and meet resistance, wouldn't it expand in a direction it could?
I've also had had open buckets with an inch or two of water in them expand and crack the bottom or the sides. In winter, I drain my tanks to the point not a single drop falls any more. Then I put a gallon or so of pink-stuff in each tank, mainly to keep the slide valves wet so they won't dry out.
