: Joachim,

: I'm in Denmark, and the temperature is dropping here too.
: I was thinking of setting up 2 or maybe 3 indoor working-halogen-spots . . .

: I had 2 of these on the floor, when i put up new wallpaper and painted my
: apartment, and they will easily heat up 20m2's indoor. Maybe not so much
: outside, but if you use the "tent method", i'm pretty sure you
: will get the heat - and light - you need.

Put one or more of these on the floor under your boat. The hot bulb causes air around it to heat and rise. In addition to the infrared light(heat) projected by the light beam this hot air can be captured by the tent above it. Keep an eye on things. The temperature can rise higher and faster than you may wish, and using a few high-wattage bulbs tends to concentrate the heat.

You get as much heat from five 100-watt bulbs as you do from one 500-watt bulb, but you can space the 5 bulbs along the length of the boat (a bit less than a meter apart should do) to give you gentle and even heat. With lower wattage bulbs you probably won't need to buy any additional materials. A few desk lamps borrowed for the day should do.

If you are in a mathematical mood you can calculate your heat rise. 1500 watts of electricity generates about 5180 BTU. NOw measure your area and convert everything to a metric equivalent. (Hey, I didn't say I was going to make this easy for you )

Good luck with this, and be sure to turn off the lights and remove them from the area when you applying resins of varnishes. You don't want anything dripping onto your lights.

PGJ