Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: "tboneuk_2000" <a_reynolds@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, February 04, 2004 9:21 PM
Subject: [Homebrew_PCBs] Re: Dissapearing Tracks in deveoper


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

There should be a faint image visible if the exposure was OK.


> 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)..?

You can reuse developer many times. I make my own from NaOH (about 12 g per
litre of water) and use it fresh each time as it's very cheap.

> 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 ?

Sounds as if it was overexposed.

Leon