Homebrew PCBs

> 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)..?
> 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 ?
 

If you are doing Pos. type resist???? and it is all coming off in 
developing then it is getting exposed otherwise it would not be 
coming off in developing solution.  Normally you can do a number of 
boards in the same batch of solution.  But if you solution mix is 
wrong it is not going to work.

Is there any chance that you are letting the board be exposed to 
light before you place the transparency or after exposure before 
placing in the developer???

Ben