Weatherproof coating for Stainless

[Bob Davis]

.A few days ago I visited my local supplier of stainless steel plate to get a few small pieces for a laser engraving (Cerdec) job. While the plates were being cut I had a bit of a chat to the boss, and he was kind enough to share some of his industry knowledge with me. My favourite gem from him was about the rust staining that SS often gets in a marine environment. He called this a "tea stain", and told me that it can best be avoided by using a protective coating of...hairspray! Apparently hairspray is basically lacquer and a coating will last well over a year. On his own boat he wipes down the SS surfaces with acetone and recoats with a can of $1.99 super-hold hairspray every year, and hasn't had a problem. I tried it on a sample I had kicking around and it came out great. The black areas look more definite and solid, and the plate has a pleasing gloss. I would guess that in an indoor setting the lacquer would last for quite a while. I hope that somebody here might find it useful, but in any case I hope readers will forgive the lack of paragraphing in this thread. For some obscure reason the "enter" key on my keyboard is having no effect while I am typing this despite working in other programs I have open.

[Keith Outten]

Bob,

Assuming the Marine environment you are concerned about is salt water stainless steel is not the preferred material because it is not resistant to salt. In a fresh water environment stainless doesn't need a coating. However, if stainless is what you have to work with then his coating tip sounds like it will work. FWIW I would try melting acrylic in acetone and painting it on the surface to see if it would last longer then one year.

BTW Inconel (http://en.wikipedia.org/wiki/Inconel) is what Newport News Shipbuilding uses on their piers and in any other area that is exposed to salt water. Anyone else who can afford inconel prefers it as well where salt is a problem.
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[Mike Null]

I am surprised at this as water is a solvent for every hairspray I've seen.

[Michael Hunter]

Blow-drying the boat after use would probably keep the stains away too.

[Jerome Stanek]

When I installed shelving gondola in drug stores I would strike a chalk line then spray it with Aquanet hair spray so it would stay until the flooring was stripped and waxed.

[Joe Pelonio]

What I have used is a product made for graffiti control. Very expensive but nice signs outdoors in a marine environment are often subject to vandalism and a little goes a long way. I think I paid $75/gallon several years ago, and a customer (parking management) once provided me with some that was more like $300/gallon. Grainger has several brands, I think both Krylon and Rustoleum make it but not available at big box stores.

http://www.sherwin-williams.com/painting-contractors/products/catalog/pro-industrial-antigraffiti-coating/

[Bob Davis]

Keith, The reason I posted this is not so much for the protective qualities of hairspray on SS (although it could be handy), but for the cosmetic (pun intended) use. The coated item has a much better appearance than a standard flat Cerdeced plate. I've also got doubts about the longevity of hairspray in a wet environment, but it appears that at least some of the ingredients are not water-soluble. Inconel is probably a better material for a marine environment, but I don't know whether or not Cerdec will work on it as well. Curse you, enter key!

[Keith Outten]

Bob,

Thanks for the tip and I will give hairspray a second look for a project in the future. I second the idea of the coating making a big difference in the look of the sign and unless stainless steel is highly polished it is a pretty bland material.

I grew up in the nuclear power plant construction industry, we used a lot of stainless steel in those days. Of particular interest were the beautiful belt buckles that tradesmen made in those days, many were works of art and they were innovative when designing custom buckles. I used to fabricate custom center pieces for some of my friends buckles, in those days I was pretty handy with a Dremel tool and solid carbide burrs. I reproduced a lot of custom logos for horse ranches that were based on cattle branding iron designs of the past. We used a lot of twisted stainless steel tig wire and EB ring to enhance a lot of buckle designs that were built from pipe, tubing, bolts and hex heads along with simple designs made from stainless electrical spacers. Had I known that we might have been able to use hairspray as a coating no doubt I would have used it often :)
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[Richard Rumancik]

I am surprised at this as water is a solvent for every hairspray I've seen.

I am sure there are a lot of recipes for hairspray - it is probably risky to lump them all into one catagory - and some may actually be suitable as a coating for stainless. Traditionally I think hairsprays tended to be lacquer-based but these days it is pretty hard to know. I just picked up a can and it has a long list of chemicals including various co-polymers. Although some hair spray may be water-soluable (with the trend these days to more environmentally-friendly products) the sprays that my daughters used in the bathroom certainly weren't soluable in water . . . I found that it required ammonia to remove hair spray from vinyl. (Ammonia is common in floor strippers.)

Usually I lean toward finding a commercial product that is actually intended to be used in a certain way for a certain purpose. Hair spray is formulated for a certain purpose and commercial lacquer for another. Hair spray is cheap and readily available so it it works for a specific purpose then great . . . However, for consistency I would be more comfortable using a can that says "provides protection for metal" on the label.

[Mike Null]

Then how did they wash it out of their hair?

[Dee Gallo]

Then how did they wash it out of their hair?

I always wondered that myself, Mike! I never used it on my hair, but when I was a printmaking major, we used hairspray when we ran out of rosin for making aquatint plates. It really is/was lacquer! Acid-proof!

[Richard Rumancik]

Then how did they wash it out of their hair?

Good question - but I don't have an answer for that . . . except they used shampoos that also have a long list of chemicals on them . . .

But that reinforces my point - hair spray is formulated for a specific purpose and has to release from hair using soap and water and ? after some number of hours. I really don't know the chemistry behind the hair spray or the shampoo, or how they react to vinyl floor or stainless. And the hair spray manufacturer won't recommend the product for anything besides use on hair.

Although sometimes one can come up with an "off-label" use for a product, the user is on their own and sometimes it takes quite a bit of R&D & $ to figure out what works and what doesn't.

[Jimmy Phillips]

Leave the hair spray at home and make sure you are using 300 series stainless......316 below waterline and 304 above.....

just my .2 cents....

[Joe De Medeiros]

Leave the hair spray at home and make sure you are using 300 series stainless......316 below waterline and 304 above.....

just my .2 cents....

the OP was specifically mentioning using it in a marine environment


Corrosion Resistance Excellent in a range of atmospheric environments and many corrosive media - generally more resistant than 304. Subject to pitting and crevice corrosion in warm chloride environments, and to stress corrosion cracking above about 60°C. Considered resistant to potable water with up to about 1000mg/L chlorides at ambient temperatures, reducing to about 500mg/L at 60°C.

316 is usually regarded as the standard “marine grade stainless steel”, but it is not resistant to warm sea water. In many marine environments 316 does exhibit surface corrosion, usually visible as brown staining. This is particularly associated with crevices and rough surface finish.

[Paul Phillips]

Nice tip on the hairspray idea but when you have to guarantee your work will last for years outside in a harsh environment, this is what we use.
http://www.nicindustries.com/clear_coatings.php

[Jimmy Phillips]

the OP was specifically mentioning using it in a marine environment

I know.....and of course your quote says "In many..."....doesn't say all! I am just giving you my 43 years of living on the Chesapeake Bay and currently owning a 38' Bertram, 23' Cobia WA, and 18' Boston Whaler experience.... :)

Of course you can always fly down here to Poquoson, VA. and I will take you out on one of the boats and you are welcome to check the stainless bolts/screws/nuts that are affected by salt water everyday as they sit at my pier.

But maybe I am wrong.............

We did re-fasten our last Sport Fisherman, a 36' Tiffany, with over 6000 silicon bronze screws, and then we used West System and bi-axial cloth to fiberglass over the mahogany hall. Now talk about corroded screws....of course they were not stainless........

Now, I really don't want to get into a Google search quote flame war........

Just letting you know what one old fisherman does and has experienced............take it or leave it.......I just know I won't be spraying any hairspray on my boat, unless it goes in the wife's hair of course! :D

Jimmy

[Joe De Medeiros]

I know.....and of course your quote says "In many..."....doesn't say all! I am just giving you my 43 years of living on the Chesapeake Bay and currently owning a 38' Bertram, 23' Cobia WA, and 18' Boston Whaler experience.... :)

Of course you can always fly down here to Poquoson, VA. and I will take you out on one of the boats and you are welcome to check the stainless bolts/screws/nuts that are affected by salt water everyday as they sit at my pier.

But maybe I am wrong.............

We did re-fasten our last Sport Fisherman, a 36' Tiffany, with over 6000 silicon bronze screws, and then we used West System and bi-axial cloth to fiberglass over the mahogany hall. Now talk about corroded screws....of course they were not stainless........

Now, I really don't want to get into a Google search quote flame war........

Just letting you know what one old fisherman does and has experienced............take it or leave it.......I just know I won't be spraying any hairspray on my boat, unless it goes in the wife's hair of course! :D

Jimmy

Jimmy, I don't deny what you say, surface corrosion on stainless (300 series) in most case has to do with surface contamination and is not true corrosion. Stainless sheets that are generally used for signage are usually 304 and have a number 4 finish on them, and are more susceptible to tea staining, and usually have not been cleaned properly to remove any surface contamination, I come from a industrial welding sheet metal background (30 years) but I don't live near salt water so I concede to your experience. My intention was not to start a Google quote flame war, but to just add additional info. I agree that hair spray would be the last thing I would use in a commercial installation.

[Jimmy Phillips]

Jimmy, I don't deny what you say, surface corrosion on stainless (300 series) in most case has to do with surface contamination and is not true corrosion. Stainless sheets that are generally used for signage are usually 304 and have a number 4 finish on them, and are more susceptible to tea staining, and usually have not been cleaned properly to remove any surface contamination, I come from a industrial welding sheet metal background (30 years) but I don't live near salt water so I concede to your experience. My intention was not to start a Google quote flame war, but to just add additional info. I agree that hair spray would be the last thing I would use in a commercial installation.

Sorry if I misunderstood your message. No offense meant.

Now I understand that 316 stainless has molybdenum added to it for increased corrosion resistance. And we do try and use 316 everywhere, but usually end up with 304 above the waterline (cheaper). Interesting part is the head is the last thing to "corrode" on the screws going into the hull. The threads, through lack of oxygen, start some type of chemical process with the non-cured resin and other molecules (too lazy at this point to Google it, so I will leave that to the physics guys) which breaks down the passive chromium oxide protection (I admit that I Googled that! :)) and then the fun happens.

What I really love is all the use of stainless steel screws/bolts in aluminum on boats! And how did that stainless screw get welded to the aluminum housing... Can we all say dissimilar metals together.....now that is fun! Why boat manf. can't take the extra 5 seconds to at least try and coat the stainless before screwing into aluminum is beyond me! Anyone ever heard of 3M 5200 marine adhesive? That stuff is awesome....nice dab on a stainless screw before going into an aluminum hole....does the trick!

l8r guys,

Jimmy

[Bill Cunningham]

Nufinish car polish.. wipe it on, let it dry, buff it off.. It will keep a car finish protected for a year through salt, carwashes, dirt, etc.. Been using it for years, and it seems to do the trick..

[Kathy Madan]

Newer hairsprays have different compositions, but using the brand Aquanet hairspray from years ago makes a great fixative. FYI, OB-Gyn offices used it for years to set the slides for pap smears. Sorry if that's too much information.

[Dan Hintz]

fyi, ob-gyn offices used it for years to set the slides for pap smears. Sorry if that's too much information.

til...... :d