Homebrew PCBs

In a message dated 1/10/2006 7:01:40 P.M. Central Standard Time,  
pharmapack@... writes:

what  kind of "photo-sensitising" you did on the  
aluminum.



This was at least 25 years back, but I THINK I used the  General Cement (?) 
firm's photosensitive spray.  It comes in a small  aerosol can, and sprays on 
as a transparent pink, and one must of course do that  in subdued light.  Then 
cover it with a box or something to let it dry  overnight.  The stuff I used, 
as I recall, had to then be exposed with UV  or sunlight for a considerable 
time, compared to "photography exposing", with  the negative-film held flat on 
it in a contact-exp. frame.  I have since  seen pre-sensitized PCB stock in 
4x6" and up pieces advertised on the ad-pages  of hobby-electronics type mags.  
NO clue how those work; faster, or  what.


[Non-text portions of this message have been removed]