I'm impressed with the sponge technique. I can etch a 4x5 inch board
in 10 minutes using about 2 ounces of FeCl. I learned to leave large
areas of toner between my traces to reduce the amount to etch. (The
green film covers these areas and eliminates pin holes commonly
reported by some users.)
The sponge wipes off the exhausted etchant/copper mix which can be
identified by its very dark color. This makes way for fresh chemical
and speeds up the process. Thin trace areas etch faster than broader
copper areas. But these can be attacked with selective sponging.
Undercutting has not been a problem.
--- In
Homebrew_PCBs@yahoogroups.com, Robert Hedan <robert.hedan@v...>
wrote:
> I also used a plastic bin, I can't see myself just dabbing at the
PCB
> without a vessel; hybrid technique, Pulsar sponge technique with
just a bit
> more etchant and a container. I had about an ounce of FeCL sloshing
around
> plus the FeCL stored in the sponge tip. The edges of the PCB were
often
> dipped in the etchant and yet it made no difference. It's like my
PCB
> etched from the center and worked outwards, in a circular pattern,
kinda
> like a portal to another dimension...
>
> (...X Files theme...)
>
> Robert
> :)
>
>
> -----Message d'origine-----
> De : Homebrew_PCBs@yahoogroups.com
[mailto:
Homebrew_PCBs@yahoogroups.com] De
> la part de bob_ledoux
> Envoyé : juillet 25 2005 17:52
> À : Homebrew_PCBs@yahoogroups.com
> Objet : [Homebrew_PCBs] Re: Experimental method
>
>
> The Pulsar Green Foil is great to allow sponging on the etchant--no
tanks
> needed. If it doesn't stick properly the first time, run it
through the
> laminator again with an unused bit of foil over the bad area. This
works
> for me.
>
>
>
> Be sure to visit the group home and check for new Links, Files, and
Photos:
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>
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