Corrosion / rust from sulfur

"stop rust" on a metal panel (top-coat galvalum), being attacked by sulfur... hmmm... lessee: sulfur+H₂O (humidity or rain) ultimately yields H₂SO₄ (sulfuric acid).

So, how to stop acid from "corroding" your metal panels?

Keep it away! (that old "isolation" factor)

Take all your cold-hard facts (plus photos) to your nearest Sherwin Williams dealer and get some expert advice on your particular app in your particular climate.

Or, switch to the new pvc-based construction materials. Best of luck to ya.

Yeah, great - except I'M the panel manufacturer...

What I'm kinda looking for is a 55 gal drum of baking soda liquid mix to spray on to stop the corrosion and possibly clean the panel edge (in place).

I realize it's acid rain (more than likely) and as I indicated, this is not a re-occurring problem but one that I need to address. Since this is a commercial application (rather than agricultural), I need to correct it first and then determine the environment exposure - Yeah, I know, figure it out first - BUT, it is in town at a middle school.

So unless some kid is peeing on the building, it will be difficult to pinpoint the cause.

sorry 'bout that - this ones biting me in the butt...

How to neutralize Sulfuric acid

Information on sulfuric acid

From the MSDS Sheet:

Procedures for Cleanup: Control source of release if possible to do safely. Contain spill, isolate hazard area, and deny entry to unauthorized personnel. Dike area around spill and pump uncontaminated acid back to process if possible. Neutralize spilled material with alkali such as sodium carbonate or sodium bicarbonate, soda ash, lime or limestone granules. If neutralized with lime rock or soda ash, good ventilation is required during neutralization because of the release of carbon dioxide gas. Allow to stand for 1-2 hours to complete neutralization, then absorb any liquid in solid absorbent such as vermiculite or clay absorbents. Place spilled material in suitable labeled containers for final disposal. Treat or dispose of waste spilled material and/or contaminated absorbent material in accordance with all local, regional and national regulations.

A thin coat of plastic, plastic sheet, or lacquer will prevent the sulfur from coming in contact with the metal.

Where is the last place a car will rust? Under the bumper sticker.

Plastic resistant to sulfuric acid atack would be suitable. Though the formation of rust on a car and sulfuric acid attacking metal are a bit different. The reaction that creates sulfuric acid from sulfur or hydrogen sulfide is biological, though it is an extremely common chemotropic reaction. The most common form of the reaction involve both iron and sulfide. So there are a number of points to interupt the reaction, the first being the removal of sulfur from water or contact with surface of metal, second is to inhibit the biological reaction, thrid is to address the sulfuric accid that is formed, fourth is to inhibit the reaction of the sulfuric acid with the metal surface.

Sulphur does not cause Iron or steel to rust, oxygen does! Sulphur combined with acid raiwater does corode Iron or steel!

Spencer.

..."OOOoooppsss"... (open-mouth-insert-foot..."been there done that myself"!).

Once again, simply in an attempt to prevent the spread of old-wivestales-and-such, by interjecting appropriate clarification:

Corrosion of metals is an electrochemical phenomenon that in no way whatsoever mandates the presence of oxygen. (Period) The omnipresence of O₂ in atmospheric exposures certainly does contribute to cathodic reactions taking place (within those REDOX reactions of corrosion) ... but, reduction of oxygen at the cathode in any corrosion cell can actually afford 'protection' to the cathode-surface(!), in the same context as the hydroxyl layer that forms on cathodically-protected subsea structures.

Similar (corrosion-related) discussions exist within CR4... such as:

Electrolysis in our dry kilns is giving us problems

Corrosion of Carbon Steel

Corrosion Retardation

If responses here do not provide sufficient insight (OP), "look-around"...

Best of luck to you, and Regards to all ~

Are you just looking to stop the rust?

Is the sulphur in mixing with moisture creating sulfuric acid?

Are you looking for a short term solution or long-term?

Keep in mind that not all coatings are created equal. We have some 3M Chemi-Tech Systems, formerly Thortex that would likely stop the rust.

Cheers,

Yes - short / long term ()

I'm guessing that the location of the few sites that are exhibiting this corrosion are due to sulfur based gas(?) that results in deposits to the edges that forms rust.

Again, we have thousands of panels in the field with the same roll form process and coatings and only a few in a specific region are rusting along the edges.

That being said, I would probably not be able to remove the contaminant but I want to save the customer relationship. They would be happy to just apply a preventative (at my expense so let's keep it reasonable) to the affected areas.

Is it possible the edges are being damaged in transportation (fork lift) and the coating is scraped or chipped off?

Nope - standard shear to length.

It's along both the sheared edge as well as the slit edge (mill slit to width).

Our 3M Corro-Tech GP would be resonable and economical solution. It is like galvinizing without the extensive process. It goes on 5.5 mils, wft and dries to 4.5 dft and is like a liquid Aluminun, and is 90% solid with low VOC's. It would give them 3 to 5 year service to manual prepared steel. Water blasting or hand tool prep.

If, you customer wanted something more long-term with zero VOC's are 3M Chemi-Tech 152LV would be the way to go. Just call our office at (248)685-7580 or go to our website at www.unconventionalsolutions.biz, and ask for me, Doug.

GA , 'Guest' ! ...

["shame-on-me" for not having inserted the link above, as I've done several times in other CR4 discussions. Signing-up for the NACE Corrosion Network (free) provides access to multitudes of experts around the globe, who face such problems day-in and day-out, and are ecstatic to share their knowledge with others. Anyone seeking to do same, follow the link to nace.org (National Association of Corrosion Engineers International) and find the page of ListServers to sign-up.]

Thanx - it does help!

CAM

Seen this product Evapo rust in a Lea Valley magazine last night. I think it will be your best solution. I have read nothing but great reviews. and it is environmentally safe.

Thanks Techno and really, THANK YOU ALL!