<p>The continued performance of a charge corona for an electrostatic copy machine is enhanced by the provision of specially configured corona wire support blocks that minimize current leakage through hygroscopic salts accumulating on the support block surface. The support blocks are configured to include a surface interruption that provides a cul-de-sac including surface which is shielded from the path of corona current and ionized gas thereby preventing accumulation of salts on the shielded portion.</p>
