Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Bob_xyz" <bob_barr@h...> wrote:
> Could you tell us the brand name of the emulsion you used, what sort 
> of quantities are available, and its shelf life?

Yes, it's called POLI-X-SOL, but you won't find it on the US because
it seems to be a local brand for my country (Argentina). It's the
cheapest one, the smallest package, 30 pesos (US$ 10) for 1Kg (2
pounds) !!, about 1 liter of product. The shelf life? Couldn't tell,
the one I bought was already expired (for a few days anyway) but
seemed to work fine.

> 
> Do you have any indication as to how well the emulsion would stand up 
> to other etchants, particularly CuCl? 

No idea, the stuff is for professional use and doesn't have
instructions. The guy who sold it to me said there were 3 types of
emulsion: the one I bought which is only water-proof, for water-based
inks for T-shirts, the chemical-proof one, for general purposes (maybe
what you need?) and the AZO-based one (AZO rings a bell from the
CD-Rs? no idea what AZO means).

> 
> Did you have to do anything special to get a smooth coating of the 
> emulsion onto the copper?

Just applied it with a brush. It's a very viscous liquid, much like
good quality latex paint, light purple when wet and almost black when
dry. I left the board on horizontal and it spread evenly (actually it
was a little to one side and a lot deposited on that side. If I can
borrow a digital camera I'll post the pix tomorrow.

> 
> 
> Regards, Bob
> 
> --- In Homebrew_PCBs@yahoogroups.com, "hjf2k2" <drgenio@h...> wrote:
> > Hi all, i've been testing a way to make photo etching cheap'n easy.
> I
> > went to a Screen-print shop and bought photosensitive emulsion, the
> > cheapest type. I mixed the components and painted the emulsion on
> the
> > copper. Then I let it dry overnight in a (pitch) dark place.
> <snip>