"Ecnerwal" wrote: (clip) A good old fashioned carbon arc light is a
wonderful UV source, but not
one that's all that easy to find these days. If you happen to have an
arc welder and a twin carbon arc torch, that would be the ticket to
rapid results - but wear your helmet and leathers, and don't catch the
wood on fire. (clip)
^^^^^^^^^^^^^^^^^^^^
They used to use carbon arc lights for burning plates in the printing
industry--they have been phased out because of the toxic fumes they produce.
I think it is hard to get the copper-coated carbon rods they use. When they
were used, they were never run more than a few minutes at a time, which I
think would be insufficient for your purposes.

Also. if you intend to use any kind of light source, you have the question
of how to get even exposure all around the bowl. You would have to rotate
it on a spit, or devise a reflective surround for the light and the bowl.

It just don't strike me as very practical.

I think the suggestion to use sunlight makes the most sense.