Rust preventive - common practice methods 1

[Jay_]

Dear,

We are in the process of fabrication diesel storage tanks.
Shape is cylindrical, horizontal and above ground.
We need to ship these tanks for a period of 1 month to the client.
The client is asking us to apply some product on the interior unpainted surface of the tanks to prevent rust formation.
Kindly note that the interior skin of the tank is still mostly with mill scale layers.
And also kindly note that we don't want to paint it with epoxy.

I searched online and all i could find that is also simple enough was cooking oil + baking soda.

Kindly note that we don't have any rust inhibitors in the local market.

Will this mixture protect the inside surface of the tank from rust formation on the top layer of the S235JR steel for a period of only 1 month?

Please provide other alternatives too even if this work, maybe your method is better.

Detailing is a hobby,

 

[TugboatEng]

Seal it and toss in a desiccant pack.

 

[Jay_]

Thanks,

The client require the surface of the tank to be coated with something. it is specified.

Detailing is a hobby,

 

[TugboatEng]

If you coat it they will have to wash it prior to placing it in service. Are they aware?

 

[EdStainless]

You need to find a source for RP (rust preventative) oil or a vapor phase inhibitor.
A home brew might last a week or two in low humidity conditions.
Why do the tanks have mill scale on the inside?
Does your client not care about trash in their fuel?
The mill scale will make it almost impossible to fully suppress rust formation, since it is already rusty.

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

 

[TugboatEng]

Ed, unfinished diesel tanks are very common in the marine industry. I despise them but they exist and they work well enough. With ultra-low sulfur diesel the MIC problem is mostly non-existent. Mill scale is easily removed with filters. Veggie oil and baking soda (alkydes) aren't so easily separated and can cause problems in the injection systems.

 

[horacio Torres]

Antirust painting is the standard for oil service. It cannot be avoided.

Horacio

https://www.linkedin.com/company/lagotuy/

 

[TugboatEng]

It can be avoided. I operate vessels built 40 years ago that don't have anti-rust painting. They work. The conditions have only gotten better. They are a pain to wash for inspection and hot work. As an operator they are a thorn in my side. As an owner, uncoated tanks are cheap and work most of the time.

 

[Jay_]

Dear,
Thank you all for your POVS.

I might go with a solution of manganese phosphate.

Although i would like to find a cheaper option.

And please note that i only meant by "mill scale" is that the tanks arent sandblasted from the inside.

And may i point out that i only want to apply this coat for shipping purposes only.

I am still thinking about organic oils option. what do you all think?

Detailing is a hobby,

 

[shvet]

@Jay
I am still thinking about organic oils option. what do you all think?

My experience is - equipment for hydrocarbons refining and handling is usually pressurized with dry nitrogen and furnished with a transport manometer. Otherwise it is preserved by a dedicated coating. Consult a reputable local retailer of industrial waxes, greases, lubes etc.

If you are looking for a cheapest option then you should look at hydrocarbons - heavy straight-run diesel, gasoils (atm, vacuum), lube oils. Modern fashion is hydrophobic polysilica sprays. Note that products with high aromatic and/or olefins content should be avoided due to polymerization and toxicity.

 

[TugboatEng]

Do you think your customer is going to be happy if their tank contaminates the fuel with manganese phosphate? Is it not possible to seal your tank? A simple desiccant pack will provide the protection you need. I would hesitate to use hydrocarbon based solutions due to the explosion risk.

 

[shvet]

Agree with above. It is strongly recommended to obtain client approval as even ppb content for inorganics (1/1'000'000'000) can become crucial in future as many inorganics are catalytic poisons or similar and drastically reduce price of an oil product.

 

[dik]

ppb? powder coat? Would a light coating of linseed oil work, or should it be inorganic?

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

-Dik

 

[shvet]

@dik
Any coating would work as period required is 1 month. Consequences are the only question. Linseed oil has nothing to do with diesel quality. I only caution that many inorganics has limits in range 1-10 ppb (parts per billion) in oil products. It means (for example) that 1 kg of improper inorganic powder has a potential in theory to contaminate 1 mln tonnes of an oil product. And not - this is not a misprint. This is not a disaster but a client risks to face with losses ~50 mln USD due to diesel price discount what is much more than cost of these tanks.

 

[Dhurjati Sen]

The best solution (as given in the first post by TugboatEng) is seldom taken.
Alas, this is the way of the world.
A pink star is all I can do.

DHURJATI SEN
Kolkata, India

 

[LittleInch]

Spray it with your choice of oils from Shell or similar?

http://www.roghanonline.com/Data-Sheet/Shell_Ensis_Fluid.pdf

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[SJones]

BS 1133-6.2
MIL-I-22110C
NACE SP0487

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[TugboatEng]

Dik, vegetable oils have alkydes in them. They are not good for fuel injection systems.