Can you actually stain stainless steel

[Sir Larry Wildman]

The other day I splashed some wine on my SD 4k. Washed it off and went on my way. But it made me wonder. If I hadn't washed it off, and let it dry on there, over time would it discolor the stainless steel? Admittedly I don't know much about this; I would assume not but you never really know.

[Dimitris76]

Short answer No. That is why stainless steel surfaces are required by law in food industry.

[trebor]

There are many different "Stainless" alloys.
Some will stain less, some are truly STAINLESS.
Rolex currently uses a STAINLESS alloy.

[Formulansx]

You might be able to slightly etch it as in dull the finish around the edge of a hard water drop that has evaporated.

[Etschell]

Originally Posted by Sir Larry Wildman

The other day I splashed some wine on my SD 4k. Washed it off and went on my way. But it made me wonder. If I hadn't washed it off, and let it dry on there, over time would it discolor the stainless steel? Admittedly I don't know much about this; I would assume not but you never really know.

only one way to find out, soak a link in red wine for a year.

[RichM]

Someone once told me it's called stainLESS, not stain proof. That should tell us something.

[GerardoG]

Originally Posted by Rich Mickol

Someone once told me it's called stainLESS, not stain proof. That should tell us something.

Exactly. While its chemical resistance is higher than other steels; it is NOT never-stain nor stain-proof.

On our daily use, SS used by Rolex will be just fine; but unusual environments can cause MAJOR damage (we had that experience with 304L and a closeby repair by a contractor... he was welding carbon steel so stainless was SEVERELY damaged. It was also in a highly acidic environment, so the equipment, after a few months, looked like it had been in the bottom of the ocean for decades).

For daily, standard use; you are ok. It is a good idea to rinse it in water after pools and ocean due to chemicals (pool) and salt (Na ions-ocean); but you will be fine.

[flyingtiger85]

Originally Posted by Etschell

only one way to find out, soak a link in red wine for a year.

[Boaters]

904 stainless is highly resistant to acids so don't think you would have a stain issue.

[natosub]

I don't think steel is sufficiently porous to "stain" like fabric or granite, but if the right (or wrong!) environment it can certainly corrode.

[rudestew]

Invented at the portland works

[NLYogi]

I sailed on chemical tankers and these have stainless steel tanks. Caustic soda, sulphuric acid, alcohols and many many very nasty chemicals are carried in these tanks and they hold up very well. In rare cases there remains some staining or discoloration but this will usually disappear over time or after cleaning by hand.
Most interesting was after carrying nitric acid; this acid brings the chrome molecules to the surface of the steel after which the tanks look almost like new. in steel industry this process is called passivation.

Stainless steel is really as inert as can be and very difficult to stain.

[DPE]

There are many grades of stainless steels. The industrial basic type is 304L, canbe magnetic due to higher carbon and can show rust spots. Also does not work well in sea water enviroments. Then a different one is 316 stainless steel. Not magnetic and a better combination of Chrome and nickle etc. Will not rust and great in a salt water enviroment. Then you have the 904 grade that Rolex use. A very high quality grade in every manner.
You will not stain the surface with wine splash, but you may find that it could remove a general age dirty surface mark off the metal. This brighter area is not a stain but just a cleaner area. Then you may decide to clean all of it to look the same.

[Hollister]

Originally Posted by Etschell

only one way to find out, soak a link in red wine for a year.

Or you could soak it in red wine for two years. These are the only two possible ways of finding out for sure.

[Hollister]

Originally Posted by DPE

You will not stain the surface with wine splash, but you may find that it could remove a general age dirty surface mark off the metal. This brighter area is not a stain but just a cleaner area. Then you may decide to clean all of it to look the same.

If I could ever make this my avatar, I will die a happy man.

[BladeDogg]

This was a VERY interesting read, thank you all for your expertise.

[Abdullah71601]

Originally Posted by Hollister

Or you could soak it in red wine for two years. These are the only two possible ways of finding out for sure.

You could accelerate the process by pressure cooking it in wine for a couple hours. Wash in warm soapy water before and after. Check it with a color analyzer before and after cooking.

If it is truly stained, washing after cooking won't affect the stain.

[armen34]

[77T]

Originally Posted by Abdullah71601

You could accelerate the process by pressure cooking it in wine for a couple hours. Wash in warm soapy water before and after. Check it with a color analyzer before and after cooking.



If it is truly stained, washing after cooking won't affect the stain.

I think 400° is the right temperature, don't you think?

[77T]

Originally Posted by Sir Larry Wildman

The other day I splashed some wine on my SD 4k. Washed it off and went on my way. But it made me wonder. If I hadn't washed it off, and let it dry on there, over time would it discolor the stainless steel? Admittedly I don't know much about this; I would assume not but you never really know.

There are ways to discolor it purposefully - for example, by using an oxidizer. But your wine wouldn't be one of them.

I have managed to stain some thin SS blades and tools by accident. But they were left in contact with rusting carbon steel items for many years in an old tacklebox. But the quality of that SS was quite inferior to 904.

[RolexNorth]

Being as the watch is stainless, had you tried spray painting your watch, the paint wouldn't hold. It would eventually rub off. The only process to be able to paint stainless would be to electrolyse the paint to the SS, however, the surface would be still suspectible to easy chipping and eventually, the paint would come off.

[douglasf13]

Originally Posted by DPE

There are many grades of stainless steels...

Here's a great run down about the steel types from Vince several years ago:

"Materials Science is an indepth field where Engineers and Scientisits not only study and test materials for their chemical, physical and other properties but select the material that best suits a particular application given a set of criteria that the material must meet. In most applications a variety of materials can meet the criteria provided so the manufacturer must choose the one that best suit their needs and desires. Certain criteria become more important and others are not but still must be met but perhaps with a lower
margin. And then there is cost but in this application cost is very low on the ladder in diving specific watches because there is a very small amount of relatively inexpensive material involved per unit. In this case some manufacturers choose material that meets all of the minimum requirements of the watchcase and excells at appearance while others choose material that also meets all of the minimum requirements but excells at scratch resistance. In life there are always cnoices and compromises.

Most manufacturers use 316L Stainless which is very similar to 904L, but there are a handful of other manufacturers that are using other rarer materials. One of them is Sinn, who is using the same steel that current German Submarines are made from which is proprietary. If we compare properties that we are talking about here from 316L to 904L to SubSteel.

Hardness - 316L and 904L are similar in hardness because they are bot austenitic steels which can not be hardened, SubSteel can be hardened by a tegiment process and it makes the steel 6 times harder than the others.

Corrosion Resistance - 316L is used in many applications where Corrosion is a fator and is very resistant but under higher temperatures in low Ph solutions 904L is superior. Sinn's Substeel is more corrosion resistant than 904L.

Magnetic - 316L and 904L have the same magnetic permeability. This is because they are similar composition austenitic steels. No only does the SubSteel share the magnetic Permeability of Austenitic Steel but it has a lower signature as would be requires in it's main application as a submarine hull material.

Strength - At 290 Mpa tensile yield and 558 Mpa ultimate yield 316L is stronger than it's counterpart 904L with 220 Mpa and 490 Mpa respectively.
The Substeel properties are not available in this specification but my guess would be that if the German's are willing to make their Submarine Hulls out of it is just fine.

Polish and luster - 904L must beat 316L because that is the main reason it was chosen by Rolex. Sinn does not polish it's Substeel watches and the German Submarines aren't either so this is unknown.

All of these steels are fine for their application in watch cases and when properly cared for will last a lifetime."

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