I've always used only the light bulb, but I like the fan idea. On 40ºF nights, the ends of the kayak maybe get to 55-60º, while the area near the bulb is 80-90ºF. (with plastic covering any openings).

Shawn

: I make preparations for closing some seams with thickened epoxy. Because I
: need good temperature, I think of warming up the kayak from the inside:
: ..I need a enery-saving, cheap, reliable method with good distribution of
: the warmth to minimize tension.
: What I have in mind is just a principle: ..a small unit (1 lightbulb)
: combined with a small fan ("PC fan") to distibute the warmth
: evenly. The deck openings could be covered with plastic to keep the heat
: inside. It should be easy to build such a tool.
: What do you think?
: -Joachim-