Homebrew PCBs

Hey Chris,
Regarding the brake fluid, I seem to recall Volkan saying that he 
made sure he wiped it ALL off so that it was dry again.  You may 
want to back up a few posts to verify that technique.

Either way, here is something else you can try for better adhesion.  
Clean the PCB using acetone.  Then, etch the board for a few 
seconds, this should break up the surface a bit and allow for better 
adhesion.  The only reason I suspect this is because I had some PCB 
material that simply would not accept toner transfer unless I did 
that.  I tried all the scrubing, sanding, polishing, washing, etc., 
the only way I got toner to stick was with a quick pre-etch.  Might 
work for ink too, you never know.

Chris



--- In Homebrew_PCBs@yahoogroups.com, Christopher Hart 
<tech_guru@...> wrote:
>
> I just ran a fresh test print through my HP Deskjet 340, with only 
Black #33, 
> and the ink works if the board is perfectly clean. Where my 
fingerprints were 
> on the board, the ink did not stick consistently. The Tarn-X did 
not work 
> well, as it seemed to increase the fingerprints. Cleaning with a 
Schotchbrite 
> pad gets the ink to stick more consistently, and with only about a 
minute of 
> air drying, the ink was much harder to remove than the Tarn-X. I 
suspect this 
> is due to the scrubber adding a little texture to the surface, 
allowing the 
> ink to grab better. The ink would not simply rinse off, as it did 
with the 
> Tarn-X. 
> 
> Scrubbed again with Scotchbrite, and applied a thin coat of DOT3 
brake fluid, 
> and all I get is puddling, and after 1 minute of air drying, 
absolutely no 
> adhesion to the copper. (All ink rinsed right off). I am better 
off with a 
> board that has been sitting around with nothing done to it. 
> 
> I did a fresh scrub with Scotchbrite on the same board, and my 
fine line test 
> pattern seems to be holding. I am going to let this board dry 
overnight 
> tonight, and If it stays good, I will test etch tonight. 
> 
> Here is my test pattern: http://i7.tinypic.com/20zsjeu.png
> 
> I don't know why all those white dots appeared when I uploaded it. 
On my last 
> test print, I didn't scrub the top very well, so there are some 
problems in 
> those areas. I will post final pictures after it has been etched.
> 
> 
> On Tuesday 25 July 2006 12:22, Christopher Hart wrote:
> > > Chris, have you ever looked at the ink used in the HP? how 
does it
> > > compare to the MIS  or Epson ink as far as viscosity (flow
> > > characteristics)? Is the inkjet head heated? What kind of 
cleaning cycle
> > > does it use?
> >
> > I haven't actually seen the Epson or MIS inks to directly 
compare them. As
> > far as I can tell, the HP inks are not heated, and the ink is 
only slightly
> > thicker than water.
> >
> > Christopher Hart
> > KC8UFV
>