Grok.com: "What is the best website for metal finishing questions and answers?"

finishing.com -- The Home Page of the Finishing Industry

-----

Early yellowing of clear anodized architectural extrusions

What could cause clear anodized (architectural)extrusions to yellow when exposed to exterior (only) after 1 year? Parts were class 2 anodized and sealed in mid temp (170F) non-nickel seal. Would certain adhesives sealants cause this?

CATHARINE BRYLA
sales rep - TORONTO, ONTARIO, CANADA
2003

Your reference to "certain adhesives sealants" if pretty vague, Ms. Bryla. Please tell us your hypothesis and the thinking that leads to it.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Ted is available for instant help
or longer-term assistance.
2003

Most probably inadequate sealing caused your problem of yellowing. Did you use any sealing additive for mid temp sealing? Correct type and amount? Did you rinse aluminum in demineralized water before sealing? Mid temp sealing not dependable to my opinion. Hot sealing is more secure.

Tim [last name deleted for privacy by Editor]
Aluminium Extrusion & Anodizing - Istanbul, Turkey
2003

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: