Which coating is better for steel for corrosive environment? 1

[Znjmech]

Hi all

I'd like to know if zinc or Tin is a better metal for coating of steel? And what should be the other pole of the electroplating?
And how is the cost of the process calculated?

 

[SwinnyGG]

Specificity is required to properly design a coating scheme.

"Corrosive environment" covers a cavernous range of potential environments and temperatures.

 

[Znjmech]

Thank you, but shall you please help me find a basis to be able to compare between these two metals in the 0 to room temperature and in a humid area( not directly in contact with water but the moist?

 

[dik]

If corrosive, I would not be considering electroplating... not anywhere good enough.
Some alternatives:

SYSTEM 05: HOT DIPPED GALVANISING
BASE METAL -STEEL
CLEANING -TO SSPC-SP 1 AND SSPC-SP 10
HDG -TO ASTM A123, THICKNESS TO Z275

SYSTEM 12: THREE PART EPOXY COATING OVER HDG
BASE METAL -HDG STEEL
CLEANING -TO SSPC-SP 1
PRIMER -DEVOE DEVRAN 201 EPOXY
SUBCOAT -DEVOE 'BARRUST 235 - MULTIPURPOSE EPOXY COATING'
TOPCOAT -DEVOE 'DEVTHANE 379H - ALIPHATIC URETHANE GLOSS ENAMEL'

SYSTEM 24: TWO PART EPOXY COATING WITH ZINC RICH PRIMER AND TOPCOAT
BASE METAL -STEEL
CLEANING -TO SSPC-SP 1 AND SSPC-SP 10
PRIMER -DEVOE 'CATHACOAT 302HB - REINF INORGANIC ZINC PRIMER
SUBCOAT -DEVOE 'BARRUST 235 - MULTIPURPOSE EPOXY COATING'
TOPCOAT -DEVOE 'DEVTHANE 379H - ALIPHATIC URETHANE GLOSS ENAMEL'

You can use products that may be more common to your area.

Dik

 

[dik]

You have to consider the level of corrosion and what the corrosive products are. HDG does not work in all environments, in particular, acidic. The two listed are a little pricey with the coating over the HDG being the more expensive one.

You should talk to a local coating supplier, in particular, if you have a really corrosive environment. My experience with coating tekkies (and not paint salesmen) is that they are quite good.

Dik