×
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

BLACK ANODIZING TOUCH UP SOLUTIONS

BLACK ANODIZING TOUCH UP SOLUTIONS

BLACK ANODIZING TOUCH UP SOLUTIONS

(OP)
Okay I have a question.  We have a part that is black anodized and need some machinging rework, which I did.  Because of the rework the black anozing was removed during machining.  Additionally, the part is 6061 aluminum with a stainless steel PEM stud pressed in. My questions are:

Is it possible to reanodize this part with the PEM inserted, or does it have to be removed or can it be masked over?

If we choice not to reanodize this part, can it be touched up by another means, besides using a black sharpie pen?  It there such a thing as an black anodize touch up pen?

Thanks
Frank

RE: BLACK ANODIZING TOUCH UP SOLUTIONS

Your anodize vendor can try to redip the part but appearance is not so good, usually vendor will want to strip and re-anodize whole which will change part dimensions 0.05-0.2mm. Not handheld touchup I know of...

They should be able to mask the PEM, solution probably has little effect on PEM but will cause bleed and poor appearance on anodize if not done. We usualy put PEM in after anodize but still mask hole to permit conductivity and prevent anodize from changing hole size.

We use semi-gloss black enamel paint like for children's airplane as touch up, can also mix with small bit of water to make finish more grey when dry and have rougher surface to match anodize.

RE: BLACK ANODIZING TOUCH UP SOLUTIONS

(OP)
Birchwood Casey BPP Super Black Touch-Up Pen

How about this product every use it?


Thanks
Frank

RE: BLACK ANODIZING TOUCH UP SOLUTIONS

LONDONDERRY,
1) Brush anodizing is possible. Dyeing and sealing are additional steps which would be done conventionally (immersion).

2) Touch-up anodizing parts w/o stripping is possible -- the parts must be sealed and any inserts well masked -- other metals  will draw all the anodizing current and burn up.  Also, stop at a lower voltage than used in the initial anodizing.

3) Touch-up using chemfilm is permitted for anodize per MIL-A-8625F: up to 5% of surface area using chemfilm per MIL-C-5541 (then use a black sharpie on the chemfilm. Just dip in deox & DI rinse before chemfilm.  SS inserts are OK (don't need masking) for chemfilm.

4) Touch-up pens per MIL-A-8625F.  The only approved chemfilm pen (Form D on QPL-81706) is the Alodine 1132 Touch-N-Prep Pen from Henkel. Easy to use: just deox. the scratch using a Q-tip wetted with 20-50 vol% nitric acid, rinse with DI water and apply. QPL:
http://assist.daps.dla.mil/quicksearch/basic_profile.cfm?ident_number=95728

Henkel's website for Alodine conversion coatings shows both a Brush Alodine® 120 Kit and the Touch-N-Prep® Pen: http://www.aerospace.henkel.com/index.cfm?ID=170

I don't see the Birchwood-Casey pen mentioned; their ALUMA BLACK® A14 BRUSH-ON is rather expensive (but it does produce a black coating w/o dyeing):
http://www.birchwoodcasey.com/store/antiquing.html


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