Are there sealants that are safe to use in a wash?

[raketemensch]

I’d rather not, but it’s currently -2 outside, maybe 55 in the basement, and I need to start up a fresh ferment.

I would just use an aquarium heater, but I don’t want scorching. I figured I would fill an empty gallon milk jug with water, drop in an aquarium heater, then run the wires out through the cap and seal them up, then wire them into this temp controller i’ve got.

The only thing worry me is sealing up the wires coming through the cap.

Thoughts?