Homebrew PCBs

oneacmename:

I have never had a problems with the Sanford Sharpie black permanent 
markers.

I notice, however, that not all of the Sanford Sharpie markers carry the 
ASTM
compliance notice on the pen. This ASTM certification refers to certain 
volatile,
spirit-based materials used in the pen. I believe that the spirit-based 
materials
are the elements that make the ink impervious to water. I have a number of
various color Sanford Sharpie pens that do not have the ASTM info on them,
and I would suspect that they are not as impervious to water as the ones 
that
carry the mark.

I'll have to go back an read the particular ASTM spec (ASTM D-4236) but
if I recall, it has to do with drafting/art/graphics items that contain 
volitiles that
are not good to breathe on a regular basis.

Of course, one must make sure that the copper is completly clean before
anything can adhere to it. Copper is a rather unstable material, and it
is prone to pick up contamination from virtually everything in the
air around it.

Someone else may have more info on this situation.
ASTM = American Society for Testing Materials

Roland F. Harriston