Homebrew PCBs

That's my experience, too.  I use emery cloth (600 grit) as well as a 
good detergent scrub and IPA (isopropyl alcohol or India Pale Ale - I 
like 'em both).  I always assumed that the soap leaves a residue that 
decreases the bonding.  Also some soaps/detergents have lanolin in 
them and that is way bad for bonding toner.

I believe the emery cloth creates more surface area for the toner to 
bond to.  My results improved significantly with that.

--- In Homebrew_PCBs@yahoogroups.com, Richard Mustakos 
<rmustakos@a...> wrote:
>   I have scrubbed the surface of boards , and washed them with 
> detergents, but until I used IPA, I was never able to get the toner 
to 
> stick reliably.  Does anyone know why the detergent doesn't clean 
the 
> oils off?  Does it leave it's own coating?
> Richard