Cooling Tower Area Paint System

[sahsanb]

Dear All,

We are observing extensive atmospheric corrosion on piping & structure adjacent to our cooling towers. Most of the piping and structure is of carbon steel in the area. Extensive corrosion is indicating that currently employed paint system is inadequate for this environment i.e. high moisture & humidity. Currently employed paint system consists of :

Epoxy Zinc Phosphate - Primer
High Build Epoxy - Intermediate
Acrylic Urethane - Top Coat

Based on your expereince please evaluate above shared paint system's adequacy as well and also recommend any improvements that can be made in this system.

Regards

 

[Inspektorro]

Hi,
Is this structures where painted under Painting Inspector supervision?
Have you got any info regarding to treated surface, their profile, conditions during painting etc?
Extensive corrosion in your case it may not be connected with wrong painting system but with conditions at which paint was applied.
First you should refer to corrosion protection report if there is.

Regards

 

[sahsanb]

These piping and structure were commissioned in 1998 by a reputed Construction Company i.e. Foster Wheeler. So while there is no such report available to indicate quality of surface preparation, rest of our plant areas painted under same company's supervision are fine indicating good engineering practices were adhered to.

Over the coarse of 15 years areas of paint blisters location were properly cleaned followed by paint application, however since the environment in this area is extremely aggressive we are looking for a paint system that can last much longer. Any suggestions would be much appreciated.

Regards

 

[Inspektorro]

Hi,
It's hard to advise any painting system via internet.
That's fine if the rest of painting system with-stand 15 years. I though it's on new building. To be honest I will not to expect in this aggressive areas any improvements due to humidity/ moisture. What you might change is intermediate to epoxy with MIO e.g. MIO flakes possess very good barrier properties, they are impermeable to water.

http://www.jotun.com/jotun/paints/2...at MIO - English (uk) - Issued.26.11.2010.pdf

it's compatible with rich zinc coatings. 1st coat in your case
But min temp. of substrate during application has to be 15*C.

Regards

 

[sahsanb]

I have applied Jotun Paint's JOTAMASTIC 87 along with HARDTOP XP on experimental basis in the area, we will see its adequacy in months to come.

 

[hokie66]

Sounds like a good experiment.