Introduction: Produce a Rich Rust Patina on Iron and Steel, Safely and Quickly, Using Common Household Chemicals

Picture of Produce a Rich Rust Patina on Iron and Steel, Safely and Quickly, Using Common Household Chemicals

  This instructable will show you a fast, safe method, using common household chemicals that you probably already have, to produce a rich rust patina on iron and steel to give it a weathered, aged appearance.

Background

I've had this Maine 'buoy bell' wind chime for about eight years now. I really like it. It has the haunting melancholy sound of a bell buoy at sea being tossed by wind and waves. It is made of COR-TEN steel which is designed to rust on the surface to create a protective barrier against further rusting. It came painted black on the outside and was supposed to develop this rich rust patina naturally over time. Well, the unpainted inside did rust completely after about a year, but the outside only rusted slightly, near the bottom, even after exposure to the sun, rain, and snow of the northeast for eight years. I wanted it to have a nice rust patina that looked like it had been hanging on the eaves of a lobster shack, at the end of a pier, for many a year, being splashed and buffeted by nor'easters and sudden gales. Seeing it was taking so long, I decided to take things into my own hands and, ah, "help" mother nature along and accelerate the process. I searched the net and found mostly dangerous methods to induce rust on steel using highly caustic or acidic chemical solutions. However I finally did find a simple safe method, using on-hand household chemicals, buried deep within a thread on the subject at a metalworking forum. I got spectacular results which have not only withstood the wind and rain of the southwest but have actually improved with the help of mother nature. I like the results so much, and there is so little practical information on the subject that is accessible to the general public, I thought I'd share this simple method with the instructables community.

Judging by the number of posts on forums asking how to do this, I see I am not the only one who wants to actually promote, rather than prevent, rust on iron and steel objects. I found out the basic information for doing this at the very cool ArtMetal forum: http://www.artmetal.com/blog/bob_turan/2009/04/rust_promoter . I'm guessing that there are more than a few instructables members who have a similar desire to prematurely age some iron/steel artifact, so I encourage people to post pictures of their resuls in the comments and add tips on how they did it so we can all learn. This method is not set in stone. Posts about useful variations on the method are always welcome.

Step 1: Materials and Tools

Picture of Materials and Tools

You will need the following:

Household Chemicals:

  • White vinegar (any brand)
  • Hydrogen Peroxide (3% -- use a fresh bottle)
  • Table salt (any kind will do, doesn't have to be sea salt)
  • Degreaser (any brand)

Tools:

  • Measuring cup
  • Measuring spoons
  • Spray bottle

Step 2: Safety First

Picture of Safety First

You will need the following safety items:

  • Safety goggles (enclosed type for chemicals not open type)
  • Chemical resistant gloves (available at home stores)

First the usual disclaimer: I will not be held responsible or liable for what you do with this information. You are ultimately responsible for using this information in a safe, conscientious manner and for not using it irresponsibly. This information is for instructional purposes only, in the spirit of sharing, and is not intended to be misused by wise guys for practical jokes, or used by people who shouldn't be handling chemicals in the first place. Young children should always have adult supervision when using any chemical. Never use chemicals when medicated (legally or otherwise) or under the influence of alcohol. These instructions are intended for, though not necessarily limited to, people with an artistic bent who just might want to rust something made out of iron or steel.

You will be using an acid, vinegar, and an oxidizer, hydrogen peroxide, so do wear the safety goggles and gloves. Be careful where you spray the solution. It is mildly corrosive and will rust anything made of iron or steel. Do this outdoors preferably in a place sheltered from the wind and away from people or pets. Do use common sense and follow common safety practices. Do not spray chemicals at anything other than the object you are trying to rust. Obviously don't spray it anywhere near people or animals. Don't breathe the vapors. They are irritating. Don't get it near your eyes or anyone else's. If you do get some in your eyes, go and rinse your eyes with cold or lukewarm water immediately. Although the chemicals used are relatively safe, common sense should prevail. If you do not possess common sense, please don't try this at home, or anywhere else for that matter.

Now that we got that out of the way let's get started.

Step 3: Degrease the Metal

Picture of Degrease the Metal

I am assuming you already have a clean iron/steel object that is free of any paint or other protective coating. If not you need to strip the finish first before performing this step. I won't go into detail about how to do that since that information is readily available. Read the label on the container of paint stripper if you use that. I used paint stripper to remove the sun-baked paint from my bell. I had to give it a second treatment to remove all traces of paint. I used a paint scraper to remove most of the paint but the paint around the rust spots required the use of an abrasive pad, wetted with the paint stripper, and a lot of elbow grease. Obviously wear goggles and gloves to do this. Nasty stuff.

Once you have clean metal you need to degrease it so chemicals will penetrate the surface. Again wearing goggles and gloves, apply degreaser according to instructions on the bottle. Be sure to remove all dirt and grime as well as oils from the metal. Rinse it well to remove all traces of degreaser. Rinse your gloves well before handling the degreased metal. You don't want to add back any dirt or oil. Don't touch the metal with bare hands or you will make oily fingerprints which might show up on the final finish. Now take your objet d'art to the outdoor place where you will spray it with chemicals.

Picture below shows clean degreased metal ready for the next step.

Step 4: Pickle the Metal

Picture of Pickle the Metal

This step is critical so don't skip it unless you actually want non-uniform rusting. At first I didn't do this and several areas would not rust because the solution could not penetrate the surface of the metal. You can see this in the picture below. I simply hung up the degreased bell and sprayed it with solution. You can see where the solution did not penetrate. Those areas did not rust at all. I then pickled the entire bell and after I did it rusted all over.

Believe it or not, you can pickle metal with the same ingredient that is used to pickle cucumbers. Yup, you guessed it, vinegar. Place your object where you can spray it from all sides, away from anything you don't want to get sprayed, including people, pets, and other objects. Put on your safety goggles and gloves. Put some vinegar in the spray bottle. Not too much, just enough to cover the object several times. Spray the object from top to bottom all around. Soak it good. Let dry and repeat several times. The more the better. Placing the object in direct sunlight will speed drying. The acid in the vinegar will etch the surface of the metal so chemicals can penetrate. If you skip this step and proceed with the next step or don't like the results of the next step, just come back to this step and spray again with vinegar. The acid in the vinegar will dissolve most of the rust. Don't worry about it. This is normal.

That's it. Now we're ready for the fun part.

Step 5: Rust the Metal

Picture of Rust the Metal

Now for the step you just can't wait to do. This is the exciting part.

Wearing your safety goggles and gloves, mix up a batch of rust accelerator adding ingredients in the order given:

  • 16 oz Hydrogen Peroxide (use a fresh bottle)
  • 2 oz White vinegar
  • 1/2 Tbsp Salt

You can use any of the pickling vinegar that is left over from the previous step. You can mix this accelerator solution directly in the spray bottle if it has a wide mouth or you can mix it first in the measuring cup, making sure to dissolve the salt, and transfer it into the bottle with a funnel. By the way I did see recommendations of up to 8 oz of vinegar but I tried that and it didn't really work as well as 2 oz. You can experiment with the proportions but this worked well for me. Same with the salt. It won't hurt to add a little more but again, this worked for me. Tighten the spray bottle cap and shake well to dissolve the salt.

I assume you have placed your awaiting object in a safe place away from people, pets, and things you don't want to get rusted and by now you are dying to see some rust. Are you ready? OK. Let's go.

Spray some solution onto your object, soaking it from top to bottom all around. Now sit back and watch the magical transformation. It will start foaming and begin to rust before your eyes. Is that something or what? If it doesn't rust then you didn't degrease it enough or you didn't pickle it enough and will have to repeat one or both of those steps. Another possibility is the temperature is too cold. This works best at elevated temperatures. It is best to let the object sit in direct sunlight and heat up a little. Let it dry and repeat. I only had to let it dry for 5 minutes but YMMV (Your mileage may vary) depending on the ambient temperature. The rust patina should deepen each time you repeat the spraying and drying cycle up to a point beyond which there is no noticeable change. Keep spraying and drying until you are satisfied with the degree of rusting. I repeated the cycle about 6 or 7 times but again, YMMV. The pictures show the progression of the rusting process.

Congratulations! You have greatly accelerated a natural process and now have a piece of metal with an attractive aged-looking patina.

Step 6: Finishing Up

Picture of Finishing Up

I would advise you to dump the remaining accelerator solution from the spray bottle and rinse the bottle and spray head well with clean water. Then spray some water through the head. This will help prevent the spring inside from rusting. You can save the solution in a jar with a plastic, not metal, top if you like, or just dump it in the toilet, flushing immediately, or in the sink, flushing it down the drain with lots of water.

Now you have several options. Be careful not to touch the surface of the rust. It is very delicate right now and powdery and can come off by rubbing. Not all of it but enough of it. You can go hang it like I did and let mother nature take over. The last picture shows the bell after a torrential downpour and subsequent drying by the sun. You can see that the color deepened from an orange color to a deeper brown color. The grain is also coarser. Or you can spray it with a fixative like acrylic or polyurethane spray. Some people recommend rubbing it with salad oil. I wouldn't, because, first, it would be messy, and second, salad oil will become gummy after a while. Mineral oil would be preferable but still messy.

And that's it. Wasn't that easy? One note. As I mentioned, my bell is made of COR-TEN steel, which is designed to rust on the surface to prevent any further rusting. Other steels are probably different in the speed at which they rust and may require more or fewer spray/dry cycles. I hope people will report their experiences in the comments section. Now that you know how it's done, go and rust something and tell us all how it came out. Have fun.

Comments

morayeel made it! (author)2017-09-10

It really works!!!

I wanted to oxidize the base of a decorative creation of mine made out of an antique marine pulley.

Within minutes I got the result I wanted!!

Thank you very much for the help!

RandW3 (author)2017-08-24

Thanks for the info. I used muratic acid to etch the surface first instead of vinegar. I got amazing results.

dstuart2 made it! (author)2017-07-30

thanks for all the tips. I etched mine with muriatic acid prior to the rusting process. This is one spray treatment allowed to sit over night.

bimalarya made it! (author)2017-07-21

I am thinking of using Corten steel on facade...I just completed my car park and allowed it to rust naturally...however it does peel off the orange rust that trickled down on the slate floor...and lot of rust to clean...however the facade is a combination of granite and Corten steel...and I do not want granite to pick up rust stains...also I do not want to use any poly coats to prevent the facade from natural rusting...so am really stuck...need to fix this for rusty powder to trickle down on facade or on the ground...am hell bent to use Corten to replace high pressure laminate that has gone bad...will try attaching some pictures. All that is brown on the facade is HPL...looks like faux wood and has weathered and I want to replace that. Also in one of the shot I have used CortenSteel as screen with laser cut letters and it has stood the test of time for last 10 years and I like the look of it. But it was a stand alone screen wall and any trickle down of rust was running into the garden floor below...but now the new application requires that no rust should settle on the granite facade...any help will be useful. I have all the Corten steel in ready to be installed...4500 square feet in all...the only way I feel is that I will let the stuff cure fully and then mount so that there is no peel off...but that is really time consuming.

makieme (author)2017-07-10

I've been using your method and love the orange patina achieved by submerging the steel in the mixture. However, I'm finding it creates an excess amount of rust dust later. Is there a non toxic way to stop this process? I can't clear coat as I'm working with far too many pieces. The other look I love is the acid wash look (similar to SusieL15), which I believe wouldn't cause all of the dust. However, I don't want to use chemicals. Do you have any advice? Thanks!

SusieL15 (author)2017-05-19

Thanks for the easy to follow instructions! I've used it on letters for barn wood signs and LOVE the look!

makieme (author)SusieL152017-07-10

Hi Susie, looks great! How did you achieve the variegated look?

Laral (author)SusieL152017-06-05

Looks great! I like the variegated look. It looks more natural.

JorisK2 (author)2017-04-20

Thank you for the detailed explanation! I used the steps described to accelerate the rusting of bended Corten steel metal and made a timelapse video of the process. Perhaps it is of use to anyone:

Laral (author)JorisK22017-06-05

Thanks for the video!

DELTA_117 (author)2017-05-20

Hey, this is really great, thanks for that! I want to achieve this look, I was wondering if you would recommend against doing this for (what I think is) a steel helmet from a functional perspective, just in terms of something that gets handled a lot, assuming it can be done at all. My thinking was to do this, and then apply a fixative as you said. Thanks!

Laral (author)DELTA_1172017-06-05

Sorry for the delay. I haven't been getting notifications for comments.

I see no reason not to do it. Keep in mind, it will be powdery at first and comes off easily. A fixative is good or you can let it stand around a while and let nature take over. You could spray it with water every day to accelerate the process.

fitterman (author)2016-06-14

What's the best way to dispose of any excess fluid? I made a little more than I can use and don't feel comfortable pouring it down the drain. (By the way, the method worked incredibly well!)

scienceinquiry (author)fitterman2017-04-16

3% hydrogen peroxide is mildly basic, so a weak acid (vinegar will do) will neutralize it...if you use a strong concentration, 30% that would be bad, therefore again neutralize it slowly as this will render lots of heat, add SLOWLY with ample SAFETY equipment until all reaction is complete...this is best done with small amounts rather than the whole enchilada

those wanting to neutralize acids, baking soda is highly recommended using the same process

Laral (author)fitterman2016-06-14

I don't know. I think such a dilute solution flushed down the toilet with a much larger volume of water would cause no harm to the plumbing or the environment. You wouldn't hesitate to flush any of the very mild ingredients individually would you, so why worry about them in combination?

I'm glad you had such success with the formula.

fitterman (author)Laral2016-06-15

My only concern is that it's mildly corrosive so I would hate to ruin any of the metal pipes in my home. Sounds like attempting to dilute it is the best plan.

I should add that overnight the rust on my planter bloomed into a wonderful result, even better than when I posted my question.

ezliving (author)2016-06-09

Hello, I am using this formula ( mostly, maybe a bit stronger H202) and am loving the results so far. Will post first photo and when done will post another. I started with a sandblasted fire pit and then added coats.

ezliving (author)ezliving2016-06-09

I have placed it and am hoping it will age gracefully, without being disturbed too much until it set's up. Will probably have a few camp fires in the meantime. Thanks for all of the great info that helped get me hear..

GautamJ7 (author)ezliving2016-06-18

I am from India and Corten is now becoming popular here. There is one doubt and personal experience that in Rains the Rust flows along with water which spoils the aesthetics of the surrounding areas turning everything into red/brown color. Is there a chemical treatment by which the flowing of the rust can be prevented.

Hope you find the above in order.

Ilikebeer247 (author)GautamJ72017-04-01

Hi try bees wax

ezliving (author)GautamJ72016-06-18

In doing some research on that, I found "Flood Penetrol" which is a rust preventive, I found one person that was using Laral's formula to create the Rust Patina and then would add a couple of coats of Penetrol to "Lock it in". It does seem to darken the color and not sure if you would want to apply it to an entire roof system..?? hope that helps. PS I have not yet tried Penetrol, but plan on doing so once my rust has set well.

Laral (author)ezliving2016-06-18

Thanks for the input.

Laral (author)GautamJ72016-06-18

I suppose you could seal it with a clear coat but I like the natural appearance of the rain streaks.

Laral (author)ezliving2016-06-10

Ohhh, it is separate from the main vessel… Then you can still have fires while you wait for it to weather.

ezliving (author)ezliving2016-06-09

OK, here is the second coat and I am inclined to leave it with this one. I will set the fire pit and let Mother Nature do the rest.

Laral (author)ezliving2016-06-10

That looks really good.

ezliving (author)Laral2016-06-10

Thank You, I will post another photo next year after some good use..

Laral (author)ezliving2016-06-10

I hope it won't take that long.

Ilikebeer247 made it! (author)2017-04-01

hi

I am rusting some weathering steel but i cant get a nice deep pattern

And i need to remain a nice orangie colour.

Any ideas

Many thanks

Nefandousned (author)2016-11-23

I masked off a portion of a piece of cold rolled sheet steel and followed the directions step by step. I then sealed with a satin polyurethane.

This looks great! How did you mask off the portions, and did you do so in the vinegar step or in the accelerator step?

TheCatCoach (author)2016-08-20

I just tried it with sheet metal, it's not working. I followed the directions. You can see the result. Maybe it doesn't work with sheet metal??? Any suggestions?

This method is for raw iron or steel. It looks like your sheet metal may have a light galvanized (zinc) coating on it specifically intended to prevent rust, many steel-based sheet metals do (that's assuming it's not stainless steel or aluminum sheet!)

thank you! I ended up first putting the boxes in muriatic acid, rinsing them off and then using the formula. Had to get rid of the zinc first.

kimberley.edwards.942 (author)2015-04-14

Hello,
I paint signs. I have a customer who would like a rusted steel sign, and I was thinking of preserving the lettering as shiny steel while rusting the background. This means I would need to mask off the letters so the muriatic acid doesn't eat through the mask. Does anybody know what I would use to coat out or mask the letters to keep them from rusting?

Do the opposite, rust the whole sign and then grind the raised letters back shiny?

Bee's wax...Ever heard of a copper plate or steel plate engraving? What they would do is coat a plate of metal in bee's wax. Then they would scratch their design out and apply the acid. When it ate away enough of the metal they would neutralize the acid and peel the wax off. The acid would only eat what the wax was not covering. These finished plate where then patted with ink and hard pressed into paper. It was used to make impressed images like this (a copper plate engraving of people making copper plate engravings...engrave-ception): https://topicsofcapricorn.files.wordpress.com/2012/01/copperplate-press-21.jpg

Laral (author)JahredT2016-01-09

That might just work but the acid could creep under the wax at the edges of the design. Some type of paint might be more resistant.

JahredT (author)Laral2016-01-10

No it won't. You melt the wax on. So the seal is very close. It conforms around the smallest changes in height. If it were Paraffin wax then yeah. But we're talking about bee's wax, it's a different beast. Just make sure what you re-expose for etching or aging is clean. even a thin film of left behind wax can prevent the acid from doing it's job.

Laral (author)JahredT2016-01-13

Why is paraffin different? I think wax would melt in this case from the heat generated by a large surface area surrounding a smaller area. It would be different for thin lines.

JahredT (author)Laral2016-01-14

Most beeswax has a higher ignition point (147F°). While some paraffin wax might burn at 157F° most of it is closer to 120F°. And you just never know unless you know the source of your wax and can email the manufacturer (it's wildly different between manufacturers). So you get a higher on average known ignition point for starters.Another thing is that paraffin has much lower friction surface due to it's additives. This means it tends to be slicker and so it doesn't bind as well or as closely, to as many surfaces. It also tends to be more crumbly or flakey then beeswax. Lastly you cannot know how all paraffin wax may react with an acid. There are so many additives from so many brands that this isn't something that you can really predict.

The reasons we use mostly Paraffin wax today is that it is relatively cheap and easy to make in large quantities (it's a petroleum by-product). we can dye it easier (bee's wax begins as a light amber color and can get darker from there so you can really only go darker then the base color). And because it is smokeless. This makes it nice for candles. But beeswax is still the choice of craftsman who have a use for wax.

If your concerned about it melting under the heat generated by the metal reacting to the acid. You could invest the top layer of wax with a good amount of baking soda. This should raise it's ignition point and naturalize fumes that come in contact with it and most acid that touches it directly.

Laral (author)JahredT2016-01-14

OK. Thanks.

JahredT (author)Laral2016-01-14

Your welcome.

Vaseline works for paint. You can rub it on the area you do not want paint to stick to and rub it off after painting, so it may work for rusting as well.

Hi, did you ever try this? Can you remember how you did it in the end. I want to do something similar with some signage at work and am looking for any advice. Thanks in advance :)

I know this sounds crazy but use finger nail polish to protect the lettering then use finger nail polish remover when finished

I don't know about muriatic acid. You'd need something impervious to acids, like a plastic-based paint, acrylic, epoxy, but then you need to remove the paint without damaging the rust. Difficult. I see a lot of rusted metal signs that have laser-cut lettering. That'd be the way to go.

JaemasW (author)2016-04-12

so I did the steps to some parts on a guitar I'm relicing. All turned out great but they are just hanging outside, I just finished them yesterday. Can I just leave them outside and they'll cure on their own?

Laral (author)JaemasW2016-04-13

Absolutely. That's exactly what I have done with the bell. The patina gets darker and deeper into the metal.

JaemasW (author)2016-04-12

I don't want to do anymore to the parts of I don't have to.

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