Alternative adhesion test for epoxy paint in a recessed groove

[waitingforthesun]

Hello,
I’m looking for a verifiable method of testing adhesion of non-metallic epoxy paint in a mill-etched groove (depth = 0.35 mm, width = 1/32”) to aluminum (7075). We cannot validate the process due to time constraints, and we cannot use the accepted method of adhesion testing (tape test/peel test) because the paint cannot be properly accessed in such a tight groove. This is for use on surgical instruments to the adhesion of the paint is critical as any chipping/peeling can pose biocompatability hazards. I'm open to all suggestions!
Thanks

 

[MintJulep]

Thermal cycle.

High pressure water spray.

 

[cezarcbc]

Can you machine a dolly to fit your part to perform pull-off test?

 

[waitingforthesun]

@ MintJulep - can you point me to any sort of standard for these tests? I wasn't able to find much information through a quick & dirty search.

@ czarcbc - considered it & messed around a little in our lab, but with the width of the groove being so narrow, I'm not confident that the test would actually prove adhesion

 

[MintJulep]

You asked for suggestions I gave you suggestions.

Don't know if there are any standards since my suggestions were off the top of my head as reasonable sounding things to do.

You might consider making simple flat plate test coupons and do comparative tests of my suggestions against a recognized standard.

 

[TVP]

ASTM (

http://www.astm.org)

has a number of different adhesion tests for coatings: D2197, D4541, D6677, B905, and B571. The latter has the following available test options:

Bend
Burnishing
Chisel-knife
Draw
File
Grind-saw
Heat-Quench
Impact
Peel
Push
Scribe-Grid

 

[israelkk]

Standards uses test samples made of plate/strip and they actually test the surface preparation process, painting process and paint quality. Anything beyond this is between you and the customer and it may lead to trouble. I would prefer using selective color anodize in the groves or even avoid groves at all and just use selective colored anodize strips and shapes per your design which should never peel off.