×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Anodine / Alochrome The Same?

Anodine / Alochrome The Same?

Anodine / Alochrome The Same?

(OP)
I'm looking for a manual process to protect bare aluminium against corrosion resistance.
I currently brush Alochrome onto damaged or missing plated areas but would like a ROHS compliant process, capable of meeting MIL-C-5541 Class 1A, but will exceed the following section to around 200 ºC

""6.14 (MIL-C-5541 Class 1A) Temperature effects on corrosion protection. Unpainted conversion coatings will commence losing corrosion resistance properties if exposed to temperatures of 140 ºF (60 ºC) or higher, during drying, subsequent fabrication, or service. As temperatures and exposure times increase, the corrosion protection of unpainted conversion coated parts decreases. The reduction is believed to result from the coating dehydrating and the resulting insolubility of the chromates within the coating.""

RE: Anodine / Alochrome The Same?

This is a known limitation of chromate conversion per MIL-C-5541 coating which is many times overlooked by designers (most designers do not bother to read the coating spec). I have seen aerospace painted critical parts that were stored under direct sun light. The paint completely peeled off because it was painted on chromate conversion coated surfaces. The solution was to replace the conversion coating with anodize coating per MIL-A-8625 prior to painting.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources