SS Coating to be Applied in the Field

[rpeng]

I am looking to apply a coating/protectang on a 304L SS tank that is used to hold oily water in a 0-2% saline solution. There is some pitting present on the plate and welds after about 3 years usage. The temperature is approximately 10-30 deg C with atmospheric pressure and a pH between 6 and 8.

There is no coating on the tank and it would be difficult to sand blast the tank or clean it perfectly. The operating engineers have recently added cathodic protection (Zinc).

Thank you,

 

[Compositepro]

Old silane residue may act as a release agent.

 

[unclesyd]

I would get in touch with Carboline and discuss you problem with them. Tank coating get a little tricky and there's wealth of products available, but nearly all require consulting with an applications engineer.

http://www.carboline.com/default.aspx

Are you going to paint the exterior surface?

 

[rpeng]

We don't plan on painting the exterior. We can probably power wash the surfaces, but sand-blasting is simply not going to happen. I spoke with Carboline and they recommend sand-blasting all surfaces to get an effective coating.

I'm not sure that silane is effective on steel. Have you heard of it being used in that application?

Thank you

 

[enmax]

Is some form of inhibition feasible? I know that nitrates for example can prevent pitting of 304L stainless steel at least to say 100-200ppm chloride. You'd need a lot of nitrate addition for 2% chloride though. There may be better inhibitors around.

http://uk.linkedin.com/pub/terry-roberts/28/a9a/a10

 

[SJones]

If you have CP on the inside of the tank, and it has been designed on the basis of no coating, why add a coating?

If you simply must coat, for immersion service with CP, you will be wasting time and money if you do not blast clean for surface preparation.

And, silane should not be saline!!

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04