Metal finishing Q&As since 1989

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PROTECTIVE LACQUER/MASKING LIQUID FOR USE DURING ANODIZING

2003

DEAR SIR,

WE HAVE AN APPLICATION AS FOLLOWS: BASE METAL AL 6061, ALUMINIUM ALLOY PARTS MADE OF THIS AL ALLOY HAVE TO BE COATED AS FOLLOWS:

BLACK ANODIC COATING AS PER MIL STANDARD ON SOME SURFACES (SAY, S1) AND CONDUCTIVE CHROMATE CONVERSION COATING ON THE REMAINING AREAS (SAY ,S2)AS PER MIL STANDARD

PROBLEM THE PEELABLE/STRIPPABLE LACQUER THAT WE ARE NOW USING TO MASK THE SURFACES S2 DURING THE BLACK ANODIC PROCESS IS UNSTABLE AND NOT PROTECTING FULLY THAT IS IT IS BECOMING POROUS/PEELING OFF. IMPROPER MASKING AT THIS STAGE IS LEADING TO PROBLEM FOR PLATING S2 SURFACE LATER

KINDLY ADVISE WHICH LACQUER/ MASKING FILM IS SUITABLE FOR THIS APPLICATION. THE PARTS ARE COMPLEX AND ADHESIVE TAPES CANNOT BE USED FOR MASKING. I WILL BE THANKFUL FOR YOUR HELP.

YOURS SINCERELY

V K V GUPTA
PROFESSIONAL ELECTRONICS MANUFACTURER - MACHILIPATNAM, ANDHRA PRADESH, INDIA