> i think with the proper tubes (4 at 7") you should have 30s.
Well I tried the Blacklite tubes that I ended up with because as I
remember M.G. Chemicials had said that they could be used but that
the none filtered or non blue tubes where recommended.
I have never exposed a board for 30 seconds. As I said it is about
5 - 6 seconds what I found that worked and have been for years. I
used a mechical timer switch to set the time. The longest I have
exposed is maybe 10 sec. I dropped down to the 5-6 secs just
expermenting to see how short of time that I could do.
I took a picture of one of my boards the other evening, I will see
about posting it in the files area. It was exposed for 5-6 sec.
developer is the M.G. Chemicals which is Sodium Hydroxide. I etch
in Ferric Chloride 5 gal. homemade bubble tank.
Ben