I don't think roughing up the board really addresses the coating adhesion
problem...usually there is some form of contaminant/disagreeable material to
the coating your using. (silicone residues when using UR for ex.)   Cleaning
is usually the first thing to look at. Are you using a saponifier,
semi-aqueous system, or solvent ?  Is it effective?  Are you removing all
processing residues?  Have you baked the boards/ensured that there is no
trapped moisture?

Process Band-aids:

For general lack of adhesion, slower initial cure cycle may allow the coating
to adhere to the substrate better, followed by a bake cycle to fully cure the
coating.

If you have problem areas/movement after application -you might try
increasing the viscosity of the coating to reduce movement after application,
layering multiple .5 - 1.0 mil coats, or spraying boards "hot" to reduce time
to tack free.

As far as roughing up the boards ... a microabrasion system used to remove
coating might "roughen" the surface enough without being detrimental.


My 2 cents,

Mike Sewell

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