Clear coat to last years outdoors

Incralac
(brass lacquer with benzotriazole)

on eBay or

Amazon

(affil links)

A. You can use Incralac ⇦this on eBay or Amazon [affil links] or any other similar proprietary product!

Today there is no clearcoat which can last so long time outdoors (Incralac can last 2 years, maybe up to 4 or 5, who knows).

Good luck!

A. 20 year outdoor exposure? That's tough. Maybe a polyurethane w/ corrosion inhibitor such as benzotriazole ⇦this on eBay or Amazon [affil links] . I don't know who makes such a product. If you need only brass color, check with the people who coat plumbing fixtures. They apply a brass-colored carbide which is supposed to last forever.

A. Simulated weathering of materials can be tested at many laboratories for the construction industry. One of the most notable being CTL (Construction Testing Laboratories), sister company of Portland Cement Association in Skokie IL. They can simulate freeze thaw conditions, abrasion, exposure to salt spray as well as UV exposure and they have the facilities to test exposure to toxic liquids, gasses, and solids as well. Oh and if the price of such experiments is a little out of your budget, standardized testing methods can be used. ASTM methods are what they use anyway. With a little gumption and some research its not totally unfeasible to set up a freeze thaw testing unit in your garage provided you're using standard testing methods and procedures. I would not recommend testing exposure to toxic materials yourself however.

Hope that helps

A. Powder coating is durable, long lasting and is available in different resins and colors including clear. Not all powdercoaters offer flexibility of color or resins. You may first try discussing your requirements with a powdercoat manufacturer and let them suggest a company that can apply the coating.

A. There is no clear coat, lacquer or vanish capable of doing such a job.

There may be industrial coatings or treatments that will endure 2 to 5 years, but not much beyond that, and a good rule of thumb is that the longer it lasts, the tougher it is to remove and restore when it becomes necessary. Top quality pH neutral polishes with the right waxes may last up to a year but require repolishing, clear coats lacquers and glazes can last much longer but require much more work for restoration once it comes due.

Your choice.

A. I have been using a product named [brand name deleted by editor] instead of your usual lacquers on all marine and outdoor restoration jobs for a bit more than a year now. It is a chemical deposit that dries to a clear coat and it does not diminish the lustre to the degree that our traditional lacquers do. It requires 24 to 36 hours to cure. I have not come across a similar substance before. On stainless work where crevice corrosion is evident I have been using it as a sealant with much success. It only comes in an aerosol can.

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Thanks, Dave.

Do you happen to know what general technology is claimed by that product -- silicate, lacquer, urethane, UV cured powder, 2-pack epoxy, or whatever?

We appreciate your appraisal, but it's impossible to know whether the secret ingredients of one brand are more or less suitable than others, which has led time after time to "No, brand xxx is way better than the brand yyy that Dave just recommended"; and then "Try zzz, it's much better than xxx or yyy" -- and the technical discussion vanishes while a race to the bottom is on, with sales managers posting gushy phony testimonials with fictitious names :-)

If anyone feels that there is a good technology for this particular problem, we'd love to hear from you. But please, this is a semi-anonymous site, with nobody knowing the vested interests of others, and we receive nearly a thousand spams a day, so testimonials to specific brands and their secret lists of ingredients have been a mess most times :-)

Thanks again.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. In keeping with the spirit of the website I will not disclose the brand name of the product, that will cover the needs discussed.

When looking for that type of durability, clearness of coating and UV stability, I would suggest going with a epoxy type Polyurea that utilizes Nano-technology.

The "good" ones only require one coat and will bond to almost anything. They are UV Stable and will provide protection you are looking for under the heat and harsh weathering. I know many County DOT's in Georgia that use this coating on road signs to fight Graffiti and protect from weathering.

A. Hi Guys. I have been looking also for a clearcoat that can be used on raw aluminum to seal and prevent oxidation. Standard clearcoats I have used in the past leave the substrate cloudy and I believe this is due to the solvents. I am an automotive refinisher and ASE certified technician and have used many brands of clears.
I have just recently came across a product that can be to actually clear coat CHROME! I am not trying to advertise for anyone so I will just state the name of the product and you can your own research. It's called clear4chrome. It's made by a company that manufactures exotic paint and finishes. It's not cheap, but most things that actually work well and last aren't. I hope this helps out. I know that it's hard to find info on this so that is why I'm stating the name of the product. Hope I'm not breaking any rules!

Hi, Jeremy. Chrome neither requires clear coating, nor benefits from it in any way, so I don't really understand what this is about ... but please put it on a truck bumper and let us know how it worked out a few months from now.

I'm not saying it doesn't work, but although chrome is never clearcoated, OEMS have often wanted to paint small areas of chrome for logos, etc., and mostly been unable to paint it really reliably. It's quite a challenge to get something to reliably stick to chrome over the years, through baking sun & frigid winters, and gravel & scrub brushes because chrome is an extremely hard metal whereas paints are relatively soft organic coatings. Thanks.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 24, 2009

A. It's not a clearcoat, it's a PVD application, Remy, of zirconium nitride or something very similar. This is a wear resistant, brass color coating which is applied after several layers of plating (which provide the reflectivity and most of the corrosion resistance). I don't think it is what the inquirer is seeking though, because it requires million-dollar machinery and is only applicable to relatively small parts or very specialized large parts like gold-tone stainless sheets.

A. It depends on the alloy and whether the item is cast or wrought, Brian, but countless millions of aluminum reflectors have been built by bright dipping and clear anodizing the polished surface.

A. Hi Roger. Anodizing is relatively clear especially on the purer aluminum alloys, but not water clear. So the thinner the clearer, but the thicker, the more protection. But anodizing has been used not only on countless millions of reflectors as I mentioned, but on super precision astronomical telescope mirrors as well. Talk to an aluminum anodizing shop which offers 'bright dipping" or "electropolishing" (most anodizing shops don't), and I'm very confident that you will find aluminum that is completely free of that haze. Good luck.

Regards,

A. I do aluminum coatings on glass for astronomical mirrors for our local, DC-area Astronomy club, and to my knowledge, no professional or academic Observatory anywhere in the world anodizes solid aluminum mirrors.
Instead, they (and we also) fabricate a glass mirror to the proper conic section geometry, to an accuracy measured in nanometers, and then coat the glass with a very thin (~90 nm) layer of vacuum-deposited aluminum or silver. The aluminum oxidizes in the air to Al2O3, or alumina, which is what rubies are made from -- totally transparent.
However, other places (but not us) can overcoat the aluminum with a thin layer of Magnesium fluoride or silicon monoxide/dioxide, which is extremely hard and durable.
Fabricating solid aluminum mirrors is extremely difficult and not worth the trouble.

  Thanks Guy. I apparently incorrectly conflated some things, which caused me to misunderstand what I was reading and confuse the solid aluminum technology used on wall mirrors with with how telescope mirrors are made. I understand now, and appreciate the correction!

Regards,

A. I've been in the metal fabricating business for forty years. Despite claims from a number of manufacturers of protective outdoor coatings for brass and bronze, the bottom line is that coatings break down. Always a continuous maintenance issue.