Ace! said:
I like to camp in sub-freezing conditions. Now that I have a Hawk I'm wondering how to keep the water from freezing. Are there 12V heating mats I can put in the truck bed that will keep the water from freezing?...
I don't have an answer, but I'm interested in the question.
Thoughts I've had on this subject in the past:
When I've gone campering in sub-freezing (even sub-zero-F) temperatures I've usually carried water in smaller containers -- 2-gallon to 7-gallon carboys which are kept above freezing because they're in contact with the warmth of the camper living space. Living space is warmer than the sub-freezing outdoors because it's warmed by cooking and the furnace.
The freshwater tank is in/under the couch/setee and in contact with the un-insulated floor, so I assume it would be more vulnerable to freezing than water stored in the camper living space. The cushion and cabinet insulate the tank
from the warmth of the living space. Which is why I haven't used the tank in winter. On the other hand, the tank volume is big so would be slower to freeze than a small volume...
I've considered the possibility of some kind of low-power heater in/under the water tank, as the OP suggested...but then I thought about the fact that the lines to the faucet would also have to be kept warm, since they're in more-or-less uninsulated cabinets, and because lines are small they'll freeze fast. I've had the sink drain line freeze frequently.
Back before I started using a catalytic heater at night -- i.e., when I was dependent on a loud and power-consuming furnace that I didn't like to run -- it sometimes got well-below freezing in the camper overnight (in winter). I've had water freeze in 2-gallon and even 5-gallon carboys, at least partially. I had to make sure that the carboy was positioned so that the spigot wasn't under-water, so that it wouldn't get iced up. Then I just had to pound on the carboy a bit in the morning to break up the ice.
I felt just like Kit Carson.