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Zinc phosphating for fasteners

Dear Sir ,

We are zinc phosphating the fasteners with process Degreasing (Alkaline ,10 min , 90 deg.C)-->Water Rinse-->HCl Pickling (As such , 10 min) --> Water rinse -->Surface Conditioner (Titanium salt , 1 min) --> Phosphating (zinc phosphate , 15 min , 85 deg.C)-->Water rinse -->Passivation--> Centrifuge drying-->Oiling -->Centrifuge drying --> Packing
We need to achieve 96 hrs of salt spray resistance as per ASTM B117. We want to achieve salt spray resistance by avoiding Hydrochloric acid pickling.

Can you suggest any proceas modification or the kind of chemicals we need to use.

Shripad Chitale

Shripad Chitale
Plating Shop Employee - Mumbai, Maharashtra, India
February 20, 2008

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Critical fasteners are often mechanically blast cleaned rather than acid activated, but this may be cost-prohibitive depending on what kind of fasteners you are dealing with.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
February 20, 2008

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March 19, 2008

SHRIPAD,

- Pre-clean parts before DEGREASING
- SUPER-WASH parts after degreasing (use hot water and blow them with air - repeast this step).
- PICKLING time is kind of high (try 2 min)
- Write notes to find the best conditions (above)
- KEYWORD Washing parts very well.

Jose Castellanos
- Minneapolis, MN, USA