Homebrew_PCBs

> Although it may not make a differance I fliped the film over, so the
> ink faced the board.

eliminate all unknown variables, good idea.

> My original trial board was exposed for 4 to 13 mins at 1 min
> intervals, now I tried exposing another board for 12 to 30 mins in 2
> min steps.
> Still not developing, should I see an image of the transfer (even a
> faint image) before developing the board ?

with the boards i used one could see a yellow/green discoloration
if you hold it at an agle against the light.

however if you put it in the developer and everything is correct you should
see instantly the pattern clearly showing against the exposed areas.

i remember that it looks like the image is "hovering" over the board
in the water for a few seconds if you have something wrong.
i tried to remember and tried to find the maual where i found the answer
but no luck. i think it means it is actually underexposed (and you have
added
more developer to get things going).

> One thing that may be worth mentioning is that for this second trial
> I used the same deveoping solution that I used for the first (is it
> normal to do this or should I have made anew batch for each
> development)..?

it degrades with time, so (open)storage is no good, but it should
definitely
last for some boards in a row.

> The original board had an image for few seconds then seem to
> dissapear in the solution, this new board exposed for longer had no
> such image. Could it be I need to expose for a much shorter time <4
> mins ?

this depends on the combination of light source and resist.
try it.
sorry that i can't help more, it seems i have forgotten the time when
starting
with photoprocess.....

st