Fitting fresh water tank heater, any advice.

Following on from the previous  thread and not wanting to hijack it, I am thinking about installing a CAK tanks thermostatically controlled heater. The electrics don'bother me just wondered whether anyone has fitted one. I see CAK tanks recommend fitting it a couple of inches up the side of the tank and they also supply a mounting plate so I guess you drill a whole in the tank large enough for the heater and fit it to the mounting plate and then fit the plate over the hole and seal it with some sort of mastic/sealer/Sikaflex etc .(what sort i wonder)
I can't access the inside of the tank without removing it completely.
Any advice appreciated
Dave

I did a similar project last November - so far so good. See https://www.autosleeper-ownersforum.com/t16425-water-tank-and-pipe-heating-project . You need to heat the pipe from the tank as that will freeze first.
Food for thought.

steve00136 wrote:I did a similar project last November - so far so good. See https://www.autosleeper-ownersforum.com/t16425-water-tank-and-pipe-heating-project . You need to heat the pipe from the tank as that will freeze first.
Food for thought.

Thanks for your advice and comments
Dave