On Thursday, September 3, 2015 at 5:26:07 AM UTC-4, Fitzgerald wrote:   
   > We are having some difficulties gluing to black anodized aluminum; most   
   > likely caused by the sealing process that closes the pores at the end of   
   > the anodisation process.   
   >   
   > I'm looking for hints/tips on what type of anodisation process and/or   
   > glue to use:   
   >   
   > - What type of acid do you use for anodizing? Standard sulfuric acid   
   > anodizing (Type II)?   
   > - What layer thickness do you specify?   
   > - What kind of dyeing do you use? Organic dyes or electrolytically   
   > deposited?   
   > - What kind of sealing process do you specify? (hot deionized water?)   
   >   
   > - What type of glue do you specify? (Epoxy / Silicon RTV?)   
   > - Any particular recommendation for a brand / part no.?   
   >   
   >   
   > Many thanks!   
      
   We stick diffraction gratings to anodized Al with Loctite 312,   
   the pack (from McMaster-Carr) comes with a primer and adhesive.   
   It's major use is to stick rear view mirrors onto car windshields.   
   It sets up pretty fast.. and if you are using gratings..   
   well be careful not to let it run into the grating grooves.  :^)   
   The good news is it's only a very thin layer, so not a lot of   
   gunk in there to change the optical path length...   
   (I had issues with other glues  either never quite curing, or changing   
   with humidity or temperature.)   
   Besides de-greasing the Al parts there's no other surface prep.   
   (well spraying on the primer..)   
      
   George H.   
      
   --- SoupGate-Win32 v1.05   
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