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  for Metal Finishing since 1989
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Parkerising with manganese dioxide

2004

Hello to all,

I tried to Parkerise by using manganese phosphate and phosphoric acid. The result I got is a dark gray colour but the surface is very rough and not smooth as I would like. Does somebody knows what is going on? Is that the normal finishing I can get or I can also have a smooth and gloss surface?

Thank you to all

Carlo Dalla Val
hobbyist - Conegliano, Italy

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Manganese phosphate can produce fairly large grain and is rough. The problem is normally overcome by a pre dip in a grain refiner. You have suppliers of metal finishing chemicals in Italy. Maybe one of them would sell you a small quantity of grain refiner and also phosphate chemicals. The proprietary phosphating chemicals will work better than home brew.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
2004

I phosphate parts for a living. the treated surfaces will be slightly rough. if they are overly rough the problem is down to overdoing the process. rinsing very soon after helps as well as it stops sludging.

ed wood
- aberdeen,scotland
February 10, 2011