Homebrew PCBs

I also had similar results using some generic photo paper. Because I  
just can't persuade that paper to go thru my old 5MP anymore, I've  
stopped using it, but I did have the (very unproven) impression that  
the extra layer of plastic would actually be quite helpful to prevent  
"pitting" during etching.

I flirted with a quick pass with some really fine grit sandpaper,  
before just letting it dry and then scraping away any white with a  
bamboo skewer (of the kind you'd make satay chicken with ... no idea  
how widely available these are, but you can get them in any  
supermarket in Aus.). Probably a really stiff brush would also do well  
and require less attention.

Now that I don't use it, I am noticing that some of my "black" areas  
do get etched a little - aka "pitting" or "etch thru" (but to further  
complicate things, I was also pretty low on toner. I have a new cart  
now, but nothing to etch for a few more weeks at least).

Adhesion, I find, is better with more passes of less heat.

PG

On 07/08/2009, at 2:43 PM, John Coppens wrote:

> On Thu, 06 Aug 2009 18:52:07 -0700
> Matthew Andrews <matt@...> wrote:
>
> > I have fairly good
> > results with respect to toner adhesion though I definitely need some
> > improvement, but what's worrying me most is that I end up with what
> > looks like a plastic layer from the paper stuck to the board that  
> will
> > not come off without heavy scrubbing with something like a scotch  
> brite
> > pad.
>
> That looks similar to problem I had (with Epson gloss paper). Try  
> using a
> tooth brush while the board is still wet. Or, when dry, try to pass  
> a not
> too hard (paint) brush over it. In my case, those deposits could be
> removed that way. The toner was quite resistant to the brushing.
> The 'plastic' is probably a gelatine-like substance which absorbs ink.
>
> Also, I wouldn't hold the iron in one place, but move it around a  
> bit. I
> think it will heat the surface more evenly that way.
>
> > 9) drop in hot soapy water for 5 min.
>
> Soaking may need a little longer, depending on the paper. Don't be  
> afraid
> to leave it 10' or more, if that helps.
>
>
>