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  for Metal Finishing since 1989
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Thickness measurement

I am looking for a portable instrument to measure conversion caotings of phosphate and chromates. If one machine can do both so much the better.

Please advise

Jack Lofstrom
Clearclad Coatings - Harvey, Il.
1998

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Pardon me for my ignorance, and I am not a chemist, but I thought the phosphate and chromate conversions are hardly a few atomic layers, or may be just a molecular level. It does not go deep like in diffusion. Once the exposed top surface atoms are converted to a compound, there is nothing more to convert.

In that case, it is hard to measure the thickness by simple means. Does that make any sense?

Mandar Sunthankar
- Fort Collins, Colorado
1998

Phosphate definitely has thickness, measureable with a micrometer amount of thickness. Mn phos can have visible needles if not done correctly.

Thickness of chromates would require SEM or similar.

Talk to any of the good instrument companies for their inputs. Phos measurement on steel is comparably cheap. Chromate measurement will be extremely expensive for most shops.

James Watts
- Navarre, Florida
1998

Chromate conversion coatings? Why not use sample plates of different conversion coat for comparison. I'm sure novamax can supply you some.

Carpo Tirol
- Brisbane, Australia
2000