John Bartley wrote:
took an exposure time of ??? It was just on and off again as fast as I
could flick the switch, almost like a flash bulb. I wonder if any out
there has any experience with "wattage" vs "exposure duration" times and
could lend some advice?


The problem is you've got at least a third variable. That is the distance
the bulb is from the paper. 100 watts is likely going to be way too
powerfull unless the bulb is quite distant from the paper. My 4x5 enlarger
uses a 150 watt bulb but the lens can easily be stopped down to F/11. Which
would cut the light by a factor of 128(I think). Use a smaller bulb. BTW I
mean the lens would be F/11 or smaller in use. The lens will stop down
further.

Fourth variable. The paper. Different papers will have different
speeds. I'm assuming you're using an enlarging paper.

Nick