Posted by Tim Lynn (208.125.132.129) 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?