How to Remove Rust From Corten Steel Sculpture

You could use evapo-rust to remove the rust then apply a VOC coating to keep it from rusting again.

thank you for the suggestion but this piece of art is rather large 7ft (t) x 6ft (w) impossible to submerse

I can use this in some other projects

I thank you for your helping response.

Gerardo

This is one of thirty some sculptures that I maintain, the only one allowed to rust. It's about 5 feet high. That's how the artist intended it to be and we are not empowered to "re-interpret' the artists thoughts.

Leave it alone, or at least move it after it is altered.

Yes Lyn, I hear you.

I can not ruin this object with some speculative procedure,my name is on the line.

At the same time I am pressed by the owner to come up with a plan for Recovering to it's original look ,can you help me with a solution that will work for sure? since you maintain other sculptures like this one, a proven hands on solution that was done before.

Thank you for your input Lyn.

Gerardo

Sorry, as near as I can tell, "its original look" would have been rust.
I've never had a piece stripped and refinished to other than the original patina/finish.
Although I have a fair idea how this alteration might be accomplished, I cannot help you.

Ok Lyn . I hear you.

Thank you for your input.

Gerardo

hey Lyn, what is the material supporting the corten steel sculptures , looking at the other pictures related they seem nice but the other material is in some rough shape.

Do you use any protection over the surface to stop the dark purple color that corten steel turns into.

Maybe the weather is less humid them in the west coast Victoria B,C Canada.

Just curious !!

The green base is concrete and the black material is marine grade plywood coated in black polyurethane. All our sculptures are mounted on precast concrete bases.

The original wood portion deteriorated and was replaced 3 years ago.

We don't treat the surface in any way.

The average relative humidity is very low in the desert.

Use a sand blaster. Walnut shells or similar for media. Automotive clear coat for finish.

Yes kramarat, do you have any pics to show me the before and after experience on a project with CORTEN steel using a procedure like the one you suggest?

I can not ERROR on this one, so if you can help me with the best proven results I will greatly appreciate it.

I must see/have a before and after results pics on Cor-ten steel !!

Thank you KramaT

Gerardo

No I don't. I missed your post and just saw it today. This is highly recommended within the art community for outdoor metal structures.

I'm not sure if you want the metal to look like a mirror, but I've had good luck doing the initial cleaning on brass, with a soft wire cup brush on an angle grinder. After that, you can use #0000 steel wool to bring it to where you want it. Of course, if you want it to look like a mirror it will require lots of elbow grease and metal polish.

You should tell the people that want this refinished, to commission future works of art in stainless steel.

This might help:

http://myweb.tiscali.co.uk/andyspatch/rust.htm

Chances are, if you are working for someone rich enough to have a sculpture of any size, they will never be satisfied with any finish you apply.You'll have to remove all the surface finish ans sand, and sand, then polish, and polish some more.If there's any humidity in the air, you will have to finish and coat in sections.Automotive clear coat for the finish.Leave it alone.

Can you confer with the original sculptor? If the piece retained a polished look for some time, maybe you or the artist himself can repeat the original procedure for the finish.

You may have here an interesting balancing act between the owner's and artist's wishes, and any covenants that might attach to the work. [Richard Serra may have some very tart stories about the subsequent handling of some of his works.]

When we have had to remove oxidation from alloys in the utility world, two or three methods would work. 1) Mechanically: A 3M flapper wheel on a grinder, media blast with "Black-beauty", or a wire brush/wheel. 2) Chemically: Avesta Pickle Paste (Red) Gel. It needs heat typically as well or allowed to sit, then it is rinsed repeatedly. It is Nasty stuff! A pro should do this, full PPE. It will attack the calcium in your bones if it gets on your skin, though they do make a paste for that as well to counter it. This step takes away any imbedded iron and re-passivates the top layer on Stainless, not sure how it would treat Cor-Ten though. If you're not able to convince the owner otherwise, a mechanical removal with a follow up coating like a clear coat is probably the trick. Good luck!

Assuming that Bright Finished is the true patina for this sculpture then there are bog standard finishing processes that can do this. The process summary is to apply graded abrasion until the desired lustre is achieved. A clear, weather resistant coating is applied to maintain the finish or it is polished everyday until the money runs out to pay someone to do that.

The OP seems really concerned that this won't do.

What disaster scenarios is the OP rehearsing that he believes may occur?

It either does or doesn't need polishing.

Does OP have a photo of the sculpture when it was shiny and new? That will help us see your objective and maybe the pitfalls of any processes.

Is leaving it alone an option?

Hi Gerardo,

Who is the artist or who built it? It looks like either; one of Miro's birds or a knock-off of either his or Brancusi's work. Generally speaking by the time an artist begins to build works of this scale He/she has become proficient with the materials or has passed the responsibility on to capable hands.

As can be recognized in the some of the other replies, no one who recognizes what Corten steel is would have intentionally used it in order to maintain a 'silver polished' look, and corten's cost above the price of generic steel and it's availability generally spurs inquiry by the purchaser to confirm their assumptions about the material's attributes. It is generally used so as to avoid painting or other coatings; as the rust which forms on the surface becomes the protective coating. This does not mean that Corten does not exfoliate like any other steel, it means that it's deterioration is much, much slower, depending on the fabricating technique and certain details... I cannot tell from the picture if there is a relief at the bottom of the sculpture and I don't know if the site is in a dry climate, but it appears to me that the maker of this sculpture did understand the idiosyncrasies of Corten.

That said, it is difficult for me to imagine that the maker had the intention of doing anything other than letting it rust and seal it's self.

A couple of notes: sealing corten with any sort of Val Oil/Turpentine mix or any of the other generic, gummy, traditional mixes that are usually applied to 'rusted steel' sculptures will accelerate defoliation, not inhibit it. Any sort of clear coat will also be trouble the same way as any other steel would begin to rust and flake the coating off. The other is: walnut shells could gently remove the rust and as long as you had a big enough sandblaster you could probably be able to pop off any caking rust without creating stroke marks that would be left by a smaller machine. And last but not least DO NOT USE 'black beauty' blasting media for this particular job. It is a coarse industrial grade and very sharp media that will leave your surface with a considerable amount of 'tooth' that will be impossible to remove and will only accelerate the weathering process.

Contacting the artist, the artist's estate or the fabricator would be my very first step if someone wanted me to take on this job... by the way, how have you determined that this is sculpture was fabricated with corten steel?

If it is solid metal, hit it and see. I would sand blast the darm thingand start the sand blasting with the lowest sand flow possible and air pressure possible. Move in slowly sweeping back abd forth quickly till I found the sweet color of metal I desired and move on to the other rust. I would then polish it with compounds till you get the shine you like and clear coat it. Of course I would do this when the human traffic is at it's lowest point on weekends or at night if possible. Be ready to clean up fast vaccum up and recycle the sand screening it to remove large particles.

This Corten steel looks pretty cool.

A car body made from it would have instant swag. Native distressed patina.

Not washing or polishing it would only enhance it.

Corten Steel is intended to form a protective barrier of rust. This, without paint, galvanizing or other protective coating.

Corten is a weathering steool and is protected by its oxide layer. It will never look like stainless steel unless you have it polished and clear coated. The sculpture since it was made of Corten it was made to look like it does. Most of the large power transmission poles are corten with no paint.

Building towers is my rice bowl.

I build them from hot dip galvanized high tensile steel. Some painted some not. Rust is not desirable. Maybe different where you are. To my knowledge there is no allowance for Corten in Tower Standard 222G, never looked for it.

Is there a high tensile variant of Corten? Even if there was, the tower element nodes, where water can dwell, would be subjected to accelerated corrosion.

You might have seen really old towers with the gal worn off, which means they are due for replacement. Where was that? Nice work if you can get it.....

Some times moss and lichen growing on towers in misty environments looks like rust. Ditto for dust in dusty environments.

Wikipedia spoke about one Corten tower which was a decorative structure (sculpture) in an urban setting....

This is the whole idea of corten steel. To form a veneer of rust to protect the rest of the steel from rusting away.

oilcan13

Look into electropolishing.

As an artist, industrial designer and member of an arts council or some, I am aware of the sculptures under your care. 1.You and the curator(s) are 100% incorrect 2. this is a blatant attempt at cheap recognition 3. you have wasted peoples time in response to your idiotic quest for job security 4. you have made a mockery of good art preservation 5. you all should be fired just for indulging in what you are doing.

I don't really see what the hubbub is about. The owner OWNES it and can leagally do what he wants, including cut it up for scrap. If the artist didn't want anyone to mess with it, he shouldn't have sold it. That was his choice. It is now out of his hands and influence. I understand the feeling of the art community but they don't own it.

Besides, even if it is polished and coated, eventually that coating will fail and if not recoated, it will return to the original patina.

If anyone really cares, make the owner an offer to buy it. Everything has its price. Like the old saying goes, Put your money...

A piece of artwork can not be modified or changed by the buyers any more than you can rewrite a book.

Artist's Rights

That's the craziest thing I've ever heard of.

I hope Snow enjoyed his day in court, because I doubt he's selling much art these days.

I think they need to have a few hunters deal with the problem...

Yeah. Good ole lawyers...............if someone's got some money, they'll go to battle over anything.

In this case, if the owner didn't want a patina, they may be able to sue the artist.

I've never thought much of those random abstract chunks of metal.

The whole world is nuts.

I guess random abstract chunks of wood are more organic....

I don't sell them though. I couldn't make any money off of them.

If I was going to do art for a living, the welded chunks of metal would be looking real good.

They have them all over the place in Raleigh. Very basic, welded metal shapes.

I probably just don't have a real artists eye. Here's the sculpture in front of the NC museum of art. I wish someone would commission me do do things like this.

US version of the law:

http://en.wikipedia.org/wiki/Visual_Artists_Rights_Act

Additional state laws may apply, if in fact you are in the US or any country with a simelar law.

Assuming you have the artists permission to alter thier work or they signed a waiver, Soda (that is, baking soda/Sodium bicarbonate) blasting may be more gentle and environmentally friendly than more agressive methods such as bead blasting - it was used to refinish the US Statue of Liberty several years ago. Alternatively, I've had great success polishing metals with fine scotch-brite pads (sold by 3M in various grades - you'd recognize a coarse grade as being a typical green kitchen scrub pad) followed by a soft buffing wheel and jewelers rouge, or simelar ultra-fine abrasive compound. Works great for putting a mirrored finish on stainless steel. A good coat of simple automotive carnuba wax periodically can also inhibit rust without painting clearcoats, which ultimately peel and look awful depending on your environment, over the work.

Be sure there are no abrasives in the wax. Johnson's Paste (disclaimer)wax works very well and is available everywhere.

Blast with walnut shells. Once a year.

At least the walnut shells are soft enough that they won't damage the sculpture.

(Its what I use on my armours...)

Oh, and check with the original maker...if he or she is still alive, they might have an idea of what was intended. Often corten steel sculptures are expected to rust. Why would the owner feel different? Work with the owner and the sculptor. And above all, do no harm to the surface of this sculpture.

And no....the owner cannot just "trash" the sculpture. The artist has some buy in, and a limited form of proprietory ownership based on copyright. (though I have not made a search to find that on line...but I have seen it written down somewhere. Normally Moral Right is invoked in such a case.)

http://www.refurbishforfun.blogspot.com/2010/08/rusty-bike.html

I tried this, and my conclusion is use paint (or clear laquer but beware even the slightest scratch to the laquer will start the rusting process and it's visible with silver-effect paint it's not). Have you considered using internal sacrificial anodes - I don't think it would work and you only want to do this once.

I forgot to say, sandblast but don't use sand due to silicosis, aluminium oxide is the preferred medium, polish - lots of work and then finish as above. If the artist oks it.

Once you finish polishing it don't bother with the protective coating. Just leave it overnight for other artists to finish it....

Yer not supposed to look at the finish, your supposed to look at the shape, that's the whole idea...The owner obviously has no understanding of art....If he or she, doesn't like it, they should sell it...but defacing art in a public display of ignorance will only end badly...

Broadcasting Tower, Leeds, United Kingdom, was voted the Best Tall Building in the World in 2010

http://en.wikipedia.org/wiki/Weathering_steel

"Weathering steel, best-known under the trademark COR-TEN steel and sometimes written without the hyphen as "Corten steel", is a group of steel alloys which were developed to eliminate the need for painting, and form a stable rust-like appearance if exposed to the weather for several years."""Weathering" means that due to their chemical compositions, these steels exhibit increased resistance to atmospheric corrosion compared to other steels. This is because the steel forms a protective layer on its surface under the influence of the weather.

The corrosion-retarding effect of the protective layer is produced by the particular distribution and concentration of alloying elements in it. The layer protecting the surface develops and regenerates continuously when subjected to the influence of the weather. In other words, the steel is allowed to rust in order to form the 'protective' coating."

I would try to contact the sculptor and ask him. If not possible, talk to the cusdodian of the art work, explain what is involved to restore it and let him make the decision.

As I remember, that's what "Corten" steel is supposed to do. The reason it was formulated was that it will not need to be painted or cared for after it was manufactured. The rust that forms is supposed to form a protective coating that will not rust further into the base once that outer "shell" has formed. You are probably looking at a never ending maintenance project if you want it to stay "shiny". Many bridge parts and guard rails are made from this stuff and they require no painting.

Maybe you could polish it and paint it with automotive clear coat paint, however I am not sure it would adhere without a primer, which of coarse has color to it. Or maybe you could polish it then take it to a chrome shop.......