Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Guys,

things are looking bad.

No matter what i do i just can't get a somewhat uniform spray pattern.
I have tried many different hole arrangements and inlet plates, and while
the amount of liquid seems to be enough it does never produce a somewhat
even pattern. It behaves totally unexpected at times, like spraying from
the topmost hole only the lower ones beeing dry (?????). My guess is it is
all because things are out-of-round by a tiny amount, especially when
rotatig. Sometimes it oscillates "pulsing" the spray pressure, at other
times it doesn't. It is running way too loud and i'm sick of seeing it to
be honest. I do not see a point where the uniformity will be better than
with a bubbler in a somewhat reasonable timeframe and the eventual
increase in etching speed is long eaten up by construction time.
I must draw a line somewhere how far i'm prepared to take this, and i have
reached it i think.
I would much rather spend my time actually making PCBs (especially
following up on the silicone paper).

My plan now is to lay this project to rest, and use the existing materials
to build a bigger, better bubble-tank with all the flaws of the old one
corrected. The slightly uneven etch and longer times are something i must
live with i fear.


Thanks for all the input, but this doesn't work for me.
The construction is no problem, the flow and pressure seems no problem,
but uniformity is a much bigger problem than i thought.


(By the way, i have found acrylic sealant to be a reasonably good adhesive
for polycarbonate/lexan, although i have in the end not used the lexan)

ST