ATM Additional...

[hclaus@clausing.com]

     FYI,  after my initial reply, numerous chemistry professionals weighed in with 
informed opinions.  Thank you all.  Unfortunately,  all of the chemical remedies involved 
the use of strong Bases.   This is unacceptable.

    The following is our company policy regarding coating removal.  It dates back to the 
1940's & fully applies to the recent situation:

                If a coating cannot be fully dissolved in the appropriate solvent;  Then 
the remaining coating will be considered ,  " Unremovable " , and the optic will be 
recoated as such.    All coating removal is done on a, " Best Effort "  basis.

    This may come as a surprise,  but there are many types of coatings that when 
deposited,  cannot be removed without polishing.   With regard to the case in question,  
the Aluminum was rendered unremovable by the nature of it's decomposition.   That is 
totally beyond my control !    Please,  think this through with me;  

        1)   The coating remained unremovable in PRECISELY the same region(s) as the most 
severe coating deterioration had been.   

        2)   If the nature of the problem were systemic,  it would have ruined the entire 
mirror surface .    THIS IS NOT THE CASE !.

        3)   FACT:  Sometimes coatings are not soluble.



    I will not take responsibility for situations that are clearly beyond my control.



    One more thing... 

    There have been some requests as to my definition of a stain,  it is as follows:

                A stain is a mark or pattern in the glass that is visible through the 
coating,  but not the result of Short-Finish, Pits or Sleeks.  


                Short-Finish is lack of polish.




Regards,

H.C.

http://www.clausing.com