[alt-photo] Cyanotype Light sources

[Rafael Frota]

Hello, friends

I´m trying get a lightbox to make cyanotypes (I need work at night) and I read that this kind of 27 W Compact Fluorescent Black Light works well

http://i203.photobucket.com/albums/aa61/PatrickDommarco/DSC01279.jpg 

I´d like to know:

1) They really work?
2) How many bulbs I have to put in a 30x40 cm wood box (to print 20x30 cm works in a 30x40 cm paper) to get a not-so-fast exposure? I don´t mind get about 20min exposure.
3) What the best distance between these bulbs and the print?
4) Any other recommendations to build (or improvise) a cheap light source (not so cheap here in Brazil).

Ps: many printmakers talk about UV facial sun bed unit. Would be great, but it´s TOO expensive buying and shipping to Brazil (almost 4 times more).

Hugs 4 all!

Rafael