Cleaning Stainless Steel - Rust

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lghawk

Veteran Member
Joined
Jan 2, 2021
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43
Vessel Make
48ft Trawler
Hi Everyone,

Wanting to know the best way to clean stainless steel which has signs of surface rust? Nothing bad... just tea staining. But what does everyone do to clean it off and make it look bright and new?

And what is everyone using to prevent it?? Any solutions?

Cheers!

Lyndon.
 
If just tea staining then Collinite Metal Wax will clean it. But in order to have a long lasting finish you then need to apply a further coating such as Collinite Paste Wax.

For deeper rust start with a gel type rust remover.
 
Bar Keepers Friend is a powdered cleaner for SS and works well on SS as well as fiberglass to remove the brown "mustache" that some get in certain waters.
I moisten a rag or sponge, sprinkle some on and wipe down the area. It doesn't take much effort as it is a mild acid which cleans & preps the SS surface. A coat of good paste wax (Colinite is great) helps protect it.
The acidity is what does the work on fiberglass as well an application depends on the surface.. swing platforms you can wet down sprinkle & brush to spread uniformly. You have to hurry w brushing to even it out as it starts to work immediately and will be blotchy until spread out.
 
3M metal restorer works well.
If you really want the brand new yacht luster back, you can take a polishing wheel with stainless polish compound and buff it back to perfect. I used a 4" wheel on a drill with the green stick compound. It's like jewelers rouge. I have found that the new ceramic sprays last about 6 months on our railings. The salt washes off easily after the ceramic is applied. It's an easy wipe on, wipe off process. Screenshot_20230918-075745.jpgScreenshot_20230918-081536.jpg
 
Lemon spray or brush it on for better control.
 
Stainless that is exhibiting rust has lost passivation - which is what prevents the corrosion in the first place.

Restoring this requires an acid bath, which can be done easily and fairly safely with citric acid.

If you wax over it without restoring the passivation, the corrosion will return fairly quickly.

There are lots of commercial products for this, but you can make your own gel using powdered citric acid, water, and fumed silica.

This link has information on different products as well as the recipe for making your own gel.

This should also take rust stains off of fiberglass - but keep it away from aluminum and brass.
 
Don't know if this is true, just something I heard.

The stainless steel does not rust. The rust you see if from the steel brusher used to polish and clean the S.S. in the manufacturing process. That's why you generally only see surface rust on new S.S. Once the brush steel is gone, so is the rust.

pete
 
Pete Meisinger said:
Don't know if this is true, just something I heard.

The stainless steel does not rust. The rust you see if from the steel brusher used to polish and clean the S.S. in the manufacturing process. That's why you generally only see surface rust on new S.S. Once the brush steel is gone, so is the rust.

pete
Click to expand...

Stainless steel gains corrosion resistance thanks to a chemical reaction of the metals used to make it with water and oxygen to form an oxide layer on the surface. Oxygen is the key component and depriving it of that will result in corrosion.

The previous owner of our sailboat bedded the external rudder components with stainless bolts. On the outside, they looked perfect. But inside the bedding, which he did a very good job of applying, they couldn't get oxygen, and they deteriorated until the mount was just flopping around. The whole thing had to be pulled off and the bolts replaced.

On a boat, lifelines, stanchions, cleats...etc are exposed to all sorts of contaminants that weaken the oxidation and pull iron to the surface where it will rust. Using 316 for stanchions but 18-8 for the nuts and bolts or a different grade for lifelines will eventually result in corrosion at the contact points. Someone sanding or grinding something close enough for dust particles to be carried by the wind where they settle in microscopic crevices on the surface will also strip away the oxide and eventually produce corrosion.

Heat will also do this - which is why after welding stainless, it has to be passivated or it will quickly begin to rust. Same with drilling or cutting it with a hacksaw or cutting tool. If you do these things, you have to passivate it afterward.
 
Bacchus said:
Bar Keepers Friend is a powdered cleaner for SS and works well on SS as well as fiberglass to remove the brown "mustache" that some get in certain waters.
I moisten a rag or sponge, sprinkle some on and wipe down the area. It doesn't take much effort as it is a mild acid which cleans & preps the SS surface. A coat of good paste wax (Colinite is great) helps protect it.
The acidity is what does the work on fiberglass as well an application depends on the surface.. swing platforms you can wet down sprinkle & brush to spread uniformly. You have to hurry w brushing to even it out as it starts to work immediately and will be blotchy until spread out.
Click to expand...

+1 for barkeepers friend, which is also available in solution in a bottle. I only just discovered this myself in the last couple of weeks. I have used a WM product for years with moderate success but after cleaning a SS grill with barkeepers friend I was seriously impressed with its efficacy.
 
Another vote for Bar Keeper's Friend.

Cheap like Borscht and easy to use.

I use the spray-on version. It works well on both the SS and the surrounding fibreglass.
 
Last edited:
DBG8492 said:
The previous owner of our sailboat bedded the external rudder components with stainless bolts. On the outside, they looked perfect. But inside the bedding, which he did a very good job of applying, they couldn't get oxygen, and they deteriorated until the mount was just flopping around. The whole thing had to be pulled off and the bolts replaced.
Click to expand...


The bedding had to have failed, which allowed seawater to contact the stainless bolts. It wouldn't corrode in a totally sealed environment. Crevice corrosion is what happens when stainless rusts due to contact with saltwater but lack of oxygen. Its the same thing we get around fasteners and in stanchion pockets on deck, or anywhere else these conditions occur.

304 is more likely to rust than 318, but contact between the two won't make either one worse. Not all components are available in 318, and well bedded good quality 304 will often (but not always) work well with minimal corrosion, if that is the best available. The best option is 318 that is correctly bedded and sealed.
 
Best I've used is Star Clean. It's like toothpaste and comes in a toothpaste type tube. You apply some to a damp sponge or Scotch Bright pad and rub it over the SS. You don't have to work hard at it. Then you clean it off with soap and water. It works really well. Don't mess with other stuff until you try this. It works well on mild rust and even bad SS welds.

https://www.amazon.com/Star-Clean-Step-Metal-Treatment/dp/B00XB315IY

My wife found some on the bottom in the Bahamas (must have fallen off another boat). I gave it a try and that's all I will use now. I found the crews of megayachts use it because it's quick and easy and does a great job.
 
Bacchus said:
Bar Keepers Friend is a powdered cleaner for SS and works well on SS as well as fiberglass to remove the brown "mustache" that some get in certain waters.
I moisten a rag or sponge, sprinkle some on and wipe down the area. It doesn't take much effort as it is a mild acid which cleans & preps the SS surface. A coat of good paste wax (Colinite is great) helps protect it.
The acidity is what does the work on fiberglass as well an application depends on the surface.. swing platforms you can wet down sprinkle & brush to spread uniformly. You have to hurry w brushing to even it out as it starts to work immediately and will be blotchy until spread out.
Click to expand...

We have had good results with Bar Keepers Friend.
 
BKF! Bar Keepers Friend.
Excellent on non skid as well!!
 
guy with a boat said:
The bedding had to have failed, which allowed seawater to contact the stainless bolts. It wouldn't corrode in a totally sealed environment. Crevice corrosion is what happens when stainless rusts due to contact with saltwater but lack of oxygen. Its the same thing we get around fasteners and in stanchion pockets on deck, or anywhere else these conditions occur.
Click to expand...

You are correct and that will teach me to type from memory rather than rereading the information I was given when I dealt with the problem - age is not kind to the brain.

I went back and reread the email from the boatyard and what they said was that the external bedding was still good and the internal areas were dry. However, they *did* say that the type of corrosion that was present did require water to form. But moisture tests of the hull in that area were negative.

They cut out and replaced the entire area doing the repair and we went about our business.

However, my main point stands - that stainless steel itself will definitely corrode and that passivation is what will remove it and prevent is from happening again. It is, in fact, the process through which Barkeeper's Friend and many other stainless steel cleaning products work - with oxalic acid.
 
DBG8492 is correct.

The reason barkeeper's friend works so well is because the active ingredient is oxalic acid. There are cheaper alternatives, but I use it too because it is convenient and readily available in a spray bottle.

Have passivated many different SS fabrications in industry with citric, oxalic, and hydrochloric acids.
 
Started out using over priced Spotless Stainless. Sounds simple to use but you can't let it dry before final scrub off. Real pain to use. Then we used Wink which is better and available at drug stores and 5 & 10's.

Now we use Z-Rust and Stain Remover Gel and love it. Melts rust away faster than anything.
 
Thanks Guys! You really are a wealth of knowledge! I will be sure to try a few of these and see how they go! Cheers!!
 
lghawk said:
Hi Everyone,

Wanting to know the best way to clean stainless steel which has signs of surface rust? Nothing bad... just tea staining. But what does everyone do to clean it off and make it look bright and new?

And what is everyone using to prevent it?? Any solutions?

Cheers!

Lyndon.
Click to expand...
The active ingredient in a lot of rust removers is Oxalic acid. I bought a jar of the pure powder from a chemical supplier which was considerably cheaper than buying the final product from West or others. You mix it with water. Another advantage is you can make a paste of it and it will sit on vertical surfaces while it works.
 
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