Checked a number of data sheets for lacquer thinner, none are or contain xylene.
My experience using lacquer thinner for non PCB purposes is that it is a more aggressive, more volatile solvent than most. As such, I could understand why it is more effective in removing organic surface contaminants from the PCB, but as far as leaving a "good" film on the board that promotes adhesion or converting the copper to something that is better sounds suspect. My guess is that is that it is just a better solvent or what was being used before was contaminated with something that interfered with adhesion.
--- In Homebrew_PCBs@yahoogroups.com, Leon Heller <leon355@...> wrote:
>
> On 10/12/2011 20:05, Roland Harriston wrote:
> > Richard:
> >
> > I think that there might be a number of compounds that are generally
> > called "lacquer thinner".
>
> Lacquer thinner is xylene.
>
> Leon
> --
> Leon Heller
> G1HSM
>