×
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

Paint adhesion 6061 vs 7075

Paint adhesion 6061 vs 7075

Paint adhesion 6061 vs 7075

(OP)
Would anyone know if paint just inherently adheres better to 7075 than 6061?

We've been doing some in-house comparisons. We use 6061, and our competitor uses 7075. And their primer seems to stick better. We are alodining the parts.

But before I dig too deeply, I'm just wondering if it's due to the base material itself, or if it's the paint/prep.  

RE: Paint adhesion 6061 vs 7075

Hi.  Paint adherence will be affected by surface preparation, you know.  Are surfaces touched after Alodine but prior to painting?  Bonds between your paint and substrate are mechanical.  That said, is your competitor adding grit blast or anchor pattern by phosphate conversion ground coat?  Chemical differences between 7075 and 6061 should not matter for you.               

William Gunnar
http://www.IndustrialCoatingsWorld.com
 

RE: Paint adhesion 6061 vs 7075

Agreed, there should be no substantial difference between the two alloys in terms of paint adherence.

RE: Paint adhesion 6061 vs 7075

Have you compared the Alodine coatings between yours and vendors parts?

There are different grades of chem film.  There is a grade that maximizes corrosion prevention at the expense of electrical impedance.  Then there's a grade the minimizes impedance at the expense of poorer corrosion prevention.  Then there's the ROHS versions.

I'm not sure if or how this affects performance as a substrate to paint though.   

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Paint adhesion 6061 vs 7075

(OP)
Well upon closer inspection yesterday, it would appear that the competitor actually anodizes, rather than just alodines.

Soooooo.....I think that might have a little something to do with it. (gee, ya think?)

Thanks all......

RE: Paint adhesion 6061 vs 7075

Wettability of the surface will generally increase with surface pre-treatment. (Acid / Alkaline etch, etc.) The alloys won't possess significant differences in adhesion as an untreated surface.

RE: Paint adhesion 6061 vs 7075

MMike1,

   The chemical films are used extensively as paint substrates.  If the paint finish really mattered to me, I would avoid anodizing.   

               JHG

RE: Paint adhesion 6061 vs 7075

drawoh--anodic coatings on aluminum have an extensive history of useage as paint bases in the aerospace industry.

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