Posted by vinnie (68.78.128.245) on March 11, 2009 at 13:18:49:
In Reply to: Thickness Consistency of Type II, Cass 2 Anodize posted by Tim Lynn on February 25, 2009 at 11:49:25:
: We are required to lapp the face on a part to a flatness of 0.0000348" and then anodize the entire part(2024-t351 alum).
: After the part is lapped and anodized our customer is experiencing leaking on the lapped face. I believe the leaking is being caused by the applied anodize after lapp causing the lapped surface to be no longer flat.
: Mil-I-8625 states a range of 0.00007"-0.001" can be applied to the part, but is the expected variation in anodize thickness on the part going to be less then the lapping tolerance of 0.0000348" or more than that?
Type II Class 2 on 2024 should only build up .0003-.0005 thats tenths. Any more coating will just leave smut on your part of the high copper content alloys. Coating will not build up on sharp corners, but the consistancy of the coating should be no more than one tenth but there could be higher coatings towards the edges of the part where there is more current density.