Gloss and Smoothness Specifications for Paint

[wchowe]

How do I specify smoothness and gloss of a painted surface. Are there GLOSS numbers? What about smooth? Can I assume, because a surface has a certain gloss it must be smooth?


Thanks
Bill

 

[CoryPad]

Yes, there are gloss numbers. Standards for this include ASTM D 523 Standard Test Method for Specular Gloss and ISO 2813 Paints and varnishes -- Determination of specular gloss of non-metallic paint films at 20 degrees, 60 degrees and 85 degrees.

http://www.astm.org/Standards/D523.htm

http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=7810

Here is a typical device used to measure it:

http://www.byk.com/instruments/products/7_1_US.php

For smoothness, you will need to consider multiple criteria. Roughness, waviness, lay, and DOI (distinctness of image) may be involved. There are multiple techniques, standards, instruments, etc. available.

You may need to contact some consultants, test labs, and vendors for help.

 

[wchowe]

My vendor is telling me that he is supplying a GLOSS-95 finish. I hate to put something (like GLOSS 95)on a print without knowing what it is or how it is verified. So, I would have to buy these standards to know what GLOSS-95 means? Thanks for the help!

Thanks
Bill

 

[IRstuff]

Perhaps like here:

http://www.genesiscoatings.com/PDFs/TECH SPEC - GCP 1000.pdf

ASTM D523 describes a 100-scale gloss value, but requires an angle as well.

TTFN

FAQ731-376

 

[dik]

It is my understanding, the materials added to reduce the gloss also tend to reduce the corrosion resistance of a coating. Materials with a high gloss generally have a better corrosion resistance.

Dik

 

[wchowe]

Okay, so GLOSS:95 @ 60 degrees. So the device that measures it at 90 degrees is at the same angle. I seem to remember (from Automotive) that painted surfaces were specified as Class 1,2,3 where Class 1 was the exterior of the car, hi gloss and no scratches allowed. Is that just automotive?


Thanks
Bill

 

[IRstuff]

I'm sure that every industry, auto, and paper, etc, have their own tribal approach to the same general problem.

TTFN

FAQ731-376