Rusted New Steel - What's the solution

[BFstr]

Hello Experts,
May I ask what do you think is solution for this problem....
Columns, beams, girts and purlins are rusted as shown in the pictures...
What is the solution to problem?

Thank you

 

[phamENG]

First step is to determine why it's rusting. Corrosive chemical environment? Near the ocean? Was the coating damaged during handling and erection?

 

[BFstr]

phamENG

No corrosive chemical environment, not near ocean.
May be during handling and storage ... and maybe improper storage until erection.
Its not just one pic I posted... all skeleton steel is rusted like this....
What is the standard remedy ?

Thx

 

[phamENG]

Broad strokes:

Step 1) stop the source of the corrosion.

Step 2) clean any loose corrosion products off.

Step 3) pick a coating system (this will depend on where you are, what's available, what the conditions are, what access is like, etc.) and prep base material accordingly.

Step 4) apply coating per manufacturer's instructions.

 

[CANPRO]

That looks like a simple primer finish. It is not expected to provide long term durability, if it is required. A typical steel member in a controlled environment is ok for primer only, but this looks like a louvre frame. I typically see that as a galvanized item.

How old is the structure? I'm not sure this is a problem with the finish - if this is in a mechanical room with air coming from the outside I'd say this is doing exactly what you expect it to. The problem may have started at the design stage with improperly specified finish. What does the original design call for in terms of finish? Is the finish appropriate for the environment? Was it applied correctly? These are the questions you need to start asking. The repair depends on the environmental conditions. Now that it is installed your options are limited, but a zinc-rich paint system could help.

 

[EdStainless]

What is the problem?
Is it a matter of cosmetics or is there a functional issue here?
Yes, this was a failure to spec the surface finish originally.
Seeing rust raining off of steel buildings is common and most industrial situations don't care.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[dvd]

Improper surface prep seems likely cause - SSPC Surface Prep

 

[BFstr]

The structure is new. Was just installation completed couple weeks back.
The question will be if we do nothing and leave it as it is what shall we expect?
Are there any members that absolutely need attention and need to be taken care?
Who is technically or practically responsible for damages and need to make the fixes?
(I cant attach one pic at the time with post but here is another one)

Thank you

 

[dik]

What was the specified coating? electroplated galv? It does not look like HDG, even poorly done. If exposed, the best fix is to wirebrush it clean and coat with a zinc rich primer because it appears to be exposed to the weather.... else, encase/enclose it with something.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dvd]

If the fabrication was supposed to meet AISC standards for fabrication, and paint and surface preparation were indicated, then you may have some protection from ANSI/AISC 303-22, Code of Standard Practice for Steel Buildings and Bridges

Search the linked document for "paint." Someone well-versed at AISC standards will generally be able to steer you through this. If there are no standards cited, and no paint and surface prep stipulated in the drawings, you are probably on your own. I am aware of at least one multi-million dollar field paint fix. I'll bet you don't forget this one.

If the fabricator is cooperative, maybe they can explain the paint used and methods. Probably need to contact the paint supplier, they will have some expertise.