Anchor pattern and primer coat

[Syahar1975]

Good morning Gents,

As far as I know the anchor pattern (measured in micron) of the steel surface after blasting should be less than the thickness of primer coat. Let say if the primer coat is 50 micron DFT so the anchor pattern should be less than 50 micron. With this scenario all valleys will be covered by primer coat.

If the anchor pattern is greater than the primer there would be pin rust on the top of the valleys.

Any other comments is highly appreciated.

 

[racookpe1978]

Thinner layer on the "peaks" but it may still cover.

 

[tbuelna]

The mean peak/valley height of the surface texture after blasting will be far less than the extreme condition of local features. But most primers applied by spraying will have a cured average thickness of at least 50 micron, and due to factors like surface tension and viscosity of the primer, there will be a film of primer covering even the highest surface asperity tips, provided the surface is prepared properly.

 

[Ron]

Pretty simple and inexpensive solution is to increase primer thickness.