Re: Extreme Cold
"The problem with "HEAT TAPE" is that " So, you treat it the same way any sailor treats any line. You never CUT a line, you just shorten up, coil it, wrap it...You take the six foot heat tape and wrap it around the fitting, or coil it up and hang it so the extra heat is there, and then tuck some bubblewrap over it to concentrate all the heat on that part.
The heat tape should self-regulate temperature so "too much" isn't a problem. In the worse case it warms up the rest of the boat.
I just had a mini-reflector (damned expensive tungsten bulb) burn out in less than 200 hours of use, when it was rated for 2500 hours. Would I trust a light bulb to keep anything from freezing? Don't think so. Yes, sailors have for ages. And you just won't hear about the ones who returned to find frozen engines blocks. That why there are block heaters, heated dipsticks, electric engine blankets, and other devices. A whole range of them. That don't burn out like light bulbs.
A light bulb is just the wrong tool for the job.