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


Selective anodising

Selective anodising

Selective anodising

Recently we have shifted from aloding our parts to anodising. This means that there might be issues with grounding the part. I heard about something called selective anodising, which is to mask or cover certain areas to prevent them from being anodised. I have contacted my supplier and they reckon the mask keeps peeling off during the electrolytic process. I wasn't able to find any information about what material should be used to mask during anodising. Not many coating specialist here know of selective anodising (probably it has less demand). What should I use to do this process?

Thanks in advance.


RE: Selective anodising

What are the exact conditions the part sees during the process? Find a pressure-sensitive adhesive (tape) which can stand up to those conditions. Alternately, find something like a grease or wax which can stand up to those conditions and you can vapor degrease and/or melt off after the process.

Impractical at scale, but in college, I did selective anodizing of titanium by hooking up the electrode to a dampened paintbrush and brushing titanium in areas where I wanted the anodizing. I also adjusted color by adjusting voltage.

RE: Selective anodising

We have used these with no problems during clear and black anodizing (vendor is using an alkaline etching process)
But you must make sure the surface is clean and then you need to really press them on and rub them into the surface to ensure good adhesion.
Our plater would actually use windex to clean the local surface then pick up and attach the masking using a exacto blade to ensure placement and then used a plastic roller or burnishing stick to press them on firmly.

An alternative is spot-facing after finishing.. (and actually turned out to be cheaper due to labor involved in applying the masking/demasking).

Its not a cheap process though.. It turned out to be around $0.50 per masking spot or $0.25 to spotface.. (volumes of 100-250 pcs per lot)

RE: Selective anodising

Google "Chem etch resist", you can use this for masking off areas for selective anodizing.

You are judged not by what you know, but by what you can do.

RE: Selective anodising

All that I found was Linered electroplating and anodising tape. Is that what you meant?

RE: Selective anodising


Have you checked out this article: http://www.pfonline.com/articles/masking-for-surfa...

It lists a number of different methods for selective plating/anodizing. One process with which I am familiar used a flexible, elastomer material for the mask. I am not sure if it was plastisol or something else like polyurethane.

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!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close