Structural Steel Painting

[DRW75]

Hey folks,
what is a standard coating system for structural steel that is in a controlled environment - i.e. standard building ?
I usually deal with corrosive (marine) environments, and have expensive coating systems which I usually spec out. For the case of a building, it seems that practically a primmer alone would do.

thanks

DRW

 

[JAE]

Some engineers do nothing - believing that an interior space - away from salt coastline - and in an interior space, you don't need anything. The steel will simply collect some surface scaling or rusting - very minor - and so no minimum coating is specified.

I go along with that belief - but I just balk at doing it as the steel sometimes sits for a time in the weather prior to and during erection. Just seems to help keep the thing a bit cleaner inside and I don't know that it adds all that much cost - most all fabricators I know use some sort of primer like red oxide.

 

[UcfSE]

All I have ever seen is the standard red oxide or some other shop primer that JAE mentions, for interior applications that is. You wouldn't want the rusty steel to bleed through to the finishes if it gets wet before the building is dried-in.

 

[Lutfi]

I agree with the above two posts. For many years, all I done is a coat of primer (2 to 4 mils thick).

I design for structural steel on the coastline and I only use Inorganic Zinc. I use three coat systems, primer, intermediate coating and the finish. Of course it all depends on the application. Inorganic zinc is not cheap but has proven to work real well and actually outperforms Hot Dip Galvanized (HDG) in my area.




Regards,
Lutfi

 

[valleyboy]

Hi DRW75

I work in the UK, and in line with the other posts here the current technical advice from steel manufacturers is that in some instances no corrosion protection is required.

Personally, I always specify either a red oxide or zinc phosphate primer. (I too have seen un-protected steelwork laying around a site for a week or two prior to erection.)

If you follow the link beneath there is a downloadable pdf listing differing paint specifications for differing expossure conditions of your steelwork.

http://www.corusconstruction.com/page_291.htm