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Need 20-year protection by electrogalvanizing

December 29, 2008

Myself Bikas working out metal forming & finishing product designing. I need a cheap coating process on steel sheet which can sustain 20 years against rust/ corrosion on outdoor extreme condition.
I tried using hot dip galvanising but during this process the flatness of sheet getting disturbed . My part needs flatness below 0.25 mm in sheet length 2.5 mtr.

Then I tried electro galvanizing , its comes good as far as flatness is concerned but not sure where it will sustain 20 years of rust free life in extreme outdoor application.

Please suggest what I should do ? is electro galvanizing will sustain 20 years corrosion-free life in extreme condition ? How much coating thickness I should do in electro galvanizing so that it could sustain 20 years rust free life?

BIKAS KUMAR
None - India

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Hi Bikas,

Zinc plating is not going to hold up outside for 20 years. You might want to look into a zinc alloy plate like zinc nickel or zinc iron properly passivated. 20 years is a tough one for plating. Paint or powder coating might be more effective.

Trent Kaufman
electroplater - Galva, Illinois
December 31, 2008

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Hi Bikas,

You might want to look at Zinc Aluminum Flake Coatings that are applied by dip-spin or sprayed on.

They should easily meet your 20 year requirement.

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India

January 15, 2009

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Hi,

I would like to know from Mr.Vahanwala whether a fat sheets can be coated with methods like Dacrotising or Zintek process where dip spin methods are used, would it be feasible technically, I think zinc alloy coating would be a good idea .
Regards,

Praveen Kumar
plating process supplier
Mumbai, India
January 18, 2009

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Yes, Thick and large Sheet metal Parts can easily be coated by Zinc Aluminum Flake process without any problems.

Regards,

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India

January 26, 2009

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Hi.
ZInc Aluminium flake is [another] solution for your application. Windmill industry also uses similar coating technology on their components to protect for 20-25 years span.

Kalyan Dhakane
Mumbai, India
March 14, 2009