Homebrew PCBs

G'day Don

I am about two weeks behind in clearing e-mails but I note that you dont
appear to have had a response as yet.

I'm afraid I dont have good news for you, unless finding a fellow sufferer
is useful.  We are both the victim of limited shelf-life of Scotch 8007.  In
my case I have a full pacxket, less about two sheets, that I bought back in
about 1992.

Nobody ever told me that it had a limited life and it certainly isn't
mentioned in the literature that came with the box but that is the simple
truth, as I found out after checking with a couple of development labs and
finally Kalex (?) in Melbourne who used to be a major agent for the stuff.
They were trying to find an alternative reversing film but hadn't been able
to find anything that was comparable in price, when last I checked about two
years ago.

I did suspect the developer at first but then I was given a huge supply of
that from a closed Govt lab.  It contained a number of very different batch
numbers but none could develop the 8007.  That was when I started to ask
questions around the trade.

I too have a considerable quantity of Ristron negative pcb material, that
may or may not still be ok.  I have been meaning to make up a  negative
design on the computer and do a trial exposure to see what state of health
it is in but haven't gotten around to it.  Hopefully it might be ok and if
so, I might be out of my jam as it is relatively easy to reverse drawings on
the pc to produce a negative - or at least it should be.  I haven't tried
that either yet.

Meanwhile, 3M has stopped making Scoth 8007 and Scotchcal, the panel
material it was originally intended to be used with.

Cheers

Bill   VK1MX & VK7MX


----- Original Message -----
From: "don2822003" <don282@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, June 17, 2004 12:55 PM
Subject: [Homebrew_PCBs] SCOTCH 8007


> Hi all, I am new to this group and come recomended by the AMATEUR
> REPAIRS group. I am in Australia and have a question. Can anyone help
> me with the instructions for using 8007 reversal film. I have used it
> a lot in the past but either my memory has failed me or the film I
> have left or the developer have gone off. I can find no information
> on the net at all. If it is the developer gone off is there any thing
> else that will do the job. I have a quantity of negative acting
> circuit board I wish to use and do not like the TTS system. Any other
> Ideas would be most welcome as I only have 1 sheet of 8007 left.
> many thanks ,
> Don VK3YV.
>
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