On 19/03/12 08:00, Russell Shaw wrote:
> On 19/03/12 12:18, Leon Heller wrote:
>> If it's dark green, it's probably exhausted.
>
> If it's dark green, it will etch perfectly well using a different chemistry if
> you use bubble agitation, and add a bit of hydrochloric acid from the hardware
> shop every few weeks.
>
> I get full etch in 10-15mins at room temperature like that.
Well, I've just filtered the etchant through a piece of kitchen roll (my
first choice was coffee filter paper -- I didn't have any, so I figured
kitchen roll would work as an alternate).
I ended up with a green liquid, and brown paper...
So I think it's a fair bet there's some kind of copper salt in the
solution, along with a tiny bit of iron (it's got a yellowish tint to it).
I've thrown in 200ml of brick cleaner (10% HCl, ~£10 for five litres
from B&Q) and set the valve on the air pump to full. Right now I have
foamy green etchant... I'm going to leave it for an hour or so and see
what happens when I throw some FR4 board offcuts in (lord knows I have
plenty of those after last night's complete abortion of a PCB etching
attempt).
This should be interesting...
Thanks,
--
Phil.
ygroups@...http://www.philpem.me.uk/