HOME / sitemapFAQsBOOKSHelp WantedsAdvertiseContact   you are here: Hotline/Forum => Letter 10994
most fun in metal finishing

Marine Corrosion of Stainless Steel


Q. I live by the ocean and we have numerous stainless steel railings (300 series).

I am looking for clear coatings that can be applied in place to protect from corrosion due to the salt atmosphere.

Mike Rozenblatt
- Manhattan Beach, California


A. Mike:

This can be a difficult problem in the salt spray. If the railings are 316 stainless steel, you should be able to passivate them to remove any residual iron on the surface and then it may not need a coating. If it is 304 or other 300 series, it may not stand up to the salt spray for very long.

Passivation in the field can be done with citric acid based pastes.

If you want to coat it to make sure that it is not ever going to rust you need to talk to a good coatings company. Good silicone based formulations can work, and they are resistant to the UV from the sun. The problem with coatings of ANY kind is that they can eventually start to peel or discolor. Then you have a major problem of rework or replacement.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois


A. Dear Mike,

Why don't you use titanium for your articles. Titanium has unique corrosion resistance in sea water.We use titanium greatly (Russia).

Andrey Igolin
- St.Petersburg, Russia


A. Ahhh yes, I would love titanium railings. Just bring money! Seriously, I have "tested" a number of products to coat SS railings on boats. Coatings that are painted on or sprayed on often look diseased within a year! Removing them is a LOT of trouble. If your railings are at least marine grade, then there are a great many products out there that will clean and then put a protective coating on the metal. This is a lot of work if your railings are heavily corroded already. For a review of products, you might look at Practical Sailor magazine [link is to info about magazine at Amazon]. It is the Consumer Reports [link is to product info at Amazon] of the sailing world. They perform field tests of products.

My own preference has been a product that contains Teflon in it as part of the coating, rather than just a wax. I put two coats of this stuff on in the spring, buff it up and it endures heavy salt spray with very little spotting for about three months or so. This is on the bow railing. On the stern (where the spray is less), 6-9 months will pass before the rail needs to be cleaned and coated again. I suppose a coating on your railing may last a year, unless you receive direct salt water spray on it. In any case... having nice shiny metal in a marine environment is always a lot of work!

If someone has the answer, I sure would like to know, too! Now if you were replacing the railings... you could consider bronze or chrome-plated brass. Each of those has its drawbacks, though, and thus, I prefer the stainless as a material.

Ronna Erickson
- Amherst, Massachusetts


A. Mike,

I hate to be negative (in fact I enjoy it!) but why metal AT ALL when in most cases {Ti and exotic Ni alloys excluded) you only have two options.

Posts etc from stainless, maybe, but rails from glass?

Posts etc from stainless, maybe, but rails from PVC.

You can get PVC piping in two really exotic colors. White and grey. Over a long period of time (U.V. attack not salt) the grey will blanche slightly. Low cost. Zilch maintenance.

I'm not sure about Monel ... after all this is a seagoing NiCu alloy and ideal for shafts ... but is it available in piping? I dunno.

Am surprised no one has suggested rhodium plating your stainless ... but as you must have enough $$$ in the first place to chose stainless, then, as the man says, go to Titanium....

The Germans have a lovely proverb,'wer die Wahl, hat die Qual' which in essence means 'decisions are painful'. So keep the Lamborgini (sorry, Jaguar) and use PVC!


freeman newton portrait Freeman Newton
- White Rock, British Columbia, Canada

freeman newton died


A. 316 Stainless Marine grade stainless steel can be rendered corrosion proof by application of Nyalic(R) a Nylonic polymer initially invented for Apollo moon shot lander, etc. We have used this product to completely protect and renovate corroded stainless steel in olympic pools /exterior situations etc including public sculptures with long lasting results in New Zealand and Australia.

John Fielding
- New Zealand


A. Hi, John. From a technical standpoint, I'm not seeing where the exposure conditions for the moon shot lander (vacuum / zero corrosion potential) have anything at all in common with corrosive salt air, but what I really don't understand is the point of using a very expensive metal like 316SST if you are going to depend on a coating to provide the corrosion resistance. What am I misunderstanding about this approach? Thanks.

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey


A. I have used Nyalic sorting out stainless around some of the local beach resorts, where 304 and 316 railings have rusted by either salt or other untoward corrosive things ... Dust from the desert here is largely iron oxide so rust can be pretty bad. Nyalic was used on US Satellites that they recovered from the sea in water landings - when it was the only method... Nyalic has been around for years but was hidden away under a Government patent

Jeff Melville
- Sydney Australia

A. G'day all!

I would just like to add my 2 cents worth to this debate.

It is my understanding that adhesives which are generally used to make a coating stick to a surface, generally start to break down after 5-7 years,this being true, if you were to use a coating for the stainless that contained an adhesive, at some stage it would require recoating. So in my thinking one then has to look at the ease of which the stainless can be recoated e.g ease of coating removal etc..

As it is my understanding that no advertising of products should be done in this forum , I will refrain ha ha...however there is a product or coating if you like that will achieve the results on stainless that some earlier posts have eluded too (and as you probably guessed it doesn't contain any adhesives) it will last as long as the surface of the substrate to which it is applied. Anyway as I said, just chucking my hat into the ring ha ha have a great day Rod!

Rod George
- Australia

Ed. note: Thank you for your patience, Rod. Yes, we do ask people to not offer testimonials to specific proprietary products. This site is for technical education in metal finishing, and little is learned from a claim that secret formula X is better than secret formula Y. Plus, it encourages a race to the bottom, with people with vested interests posing as satisfied customers and posting with fictitious names :-(
Finally, we receive a hundred spams a day from China, forcing us to simply throw away almost all e-mail from China without even reading it; we would hate to see this problem spread to other countries.


Q. Our house balcony has stainless steel hand railing (tubular section, don't know what grade of SS) we live about a kilometer from the coast. The stainless steel discolors and shows surface rust and requires too frequent polishing with a metal polish (available at the supermarket). Is there something better that I can do to protect the SS? Is there a clear coating, or treatment (preferably without having to remove the handrail) that I could use?


Tom Ryan
home owner - Sydney, NSW, Australia


A. I am a project manager at a custom metal fabricator, We have used stainless steel a lot over the time that I have been here and we have just found out about a product called Sharkhide.
So far we have not had any problems with it; I don't know about any kind of removal before reapplying, but the initial application is just simply wipe it on with a rag.
It seems to do the job of stopping any corrosion from forming.
I found it on the web while trying to find a coating for one of the jobs I had and decided to take a chance.

Jeremy Spalding
- Sanford, Florida

Ed. note: Sharkhide is a supporting advertiser of this website.

April 13, 2012

A. Sharkhide seems to be a great product for protecting metals,I am trying to get some to New Zealand for my Harley but the USA distributor, Flatwater Inc. do not have a DG Export licence.

Greg Drower
- Auckland,New Zealand

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS



JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & DevicesUsed & Surplus

©1995-2014     -    Privacy    -    Search