Corrosion of steel adjacent to cooling tower
Corrosion of steel adjacent to cooling tower
(OP)
I am new to this forum, so forgive me if my question has already been answered.
Are there any corrosion effects to structural steel (A36) by biocides, algaecides, or chemicals normally used in air conditioning cooling towers?
Are there any corrosion effects to structural steel (A36) by biocides, algaecides, or chemicals normally used in air conditioning cooling towers?





RE: Corrosion of steel adjacent to cooling tower
RE: Corrosion of steel adjacent to cooling tower
RE: Corrosion of steel adjacent to cooling tower
I'd try to get an established coating vendor/applicator to take a look and see if they'll clean and recoat--and give you a reasonable gaurantee period.
RE: Corrosion of steel adjacent to cooling tower
Comments & questions:
1) What is the age of the coating?
2) What is your climate, T range & sunlight exposure?
3) Rain? sometimes rain-washed areas last much longer than where deposits accumulate. If so, washing helps.
4) What was the initial surface prep? Mill scale? Blasted to white metal and promptly coated? Zinc-coated grit is available if cannot coat promptly and prevents flash rusting.
5) Alternatively, treating the blasted metal with a dilute phosphoric acid-type wash primer is a good pretreatment. See http://www.finishing.com/198/33.html for references to MIL specs. that you can download from ASSIST: http://assist2.daps.dla.mil/quicksearch/
6) Galvanic corrosion can occur between mill scale and steel, as well as between the constituent ferrite & carbide phases of the steel.
7) ‘Penetrating’ sealer is only meaningful if you have something porous, like concrete.
8) Aluminum paint as applied is only a barrier layer. It doesn’t give galvanic protection unless in direct contact with steel. You are better off with a zinc-rich epoxy primer.
9) Topcoat should be polyurethane, not epoxy, for UV resistance. Of course, must be compatible with primer.
10) Please describe the failure mode in more detail. Are the layers adhering to each other? Is the paint failing in spots & then corrosion spreading beneath?
RE: Corrosion of steel adjacent to cooling tower