Homebrew PCBs

Kiwi Edge Dressing is a shoe shine product used to re-blacken leather shoe
soles.  I tested it against a a sharpie pen I had on hand as etch resist.
The edge dressing seems impervious to the etchant.  I actually left the
board in the etchant long enough to completely etch both the naked copper
and the copper originally under the sharpie.

There was some undercutting as a result of the extended etch time.


On 11/28/06, JanRwl@... <JanRwl@aol.com> wrote:
>
>
> In a message dated 11/27/2006 5:34:09 A.M. Central Standard Time,
> lez.briddon@... <lez.briddon%40googlemail.com> writes:
>
> Do some other pens work better?
>
> I have READ that German-made Städtler red works good as lacquer paint, but
> I
> have NOT been able to find those locally.
>
> Sharpie black is all I have tried, and IF the copper has been CLEANED with
>
> lacquer-thinner and dried with paper-towels, and NEVER touched, that will
> "sorta work". But the Sharpie ink was never intended as "etch resist" so
> it is
> only "by accident" that it works at all. I suspect phases of the moon have
> to
> be JUST right for it to do at all. I have NO idea how the TEMPERATURE of
> the etchant affects the "life" of the Sharpie ink on the copper, but I
> think
> SPEED in handling and clearly GREATER than usual care is necessary for
> ANYthing
> good to happen with that! The etch-resist pens Radium Scat sold had a
> "thicker paint" but I haven't seen those in some time, now. No clue if
> they quit
> making those. But they didn't have much shelf-life at all!
>
> Surely there is a reader of this group who has money to invest who can
> open
> a little "PCB-Resist-Pen" factory and sell us EXCELLENT resist-pens that
> will
> last for WEEKS, even if occasionally left OPEN overnight, for 69¢ each!
> Wot? Jan Rowland
>
> [Non-text portions of this message have been removed]
>
>  
>


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