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  for Metal Finishing since 1989
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How to Rust Steel On Purpose

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Q. I am trying to get the engine stamp pad, which is located on the engine block, right in front of the right side (pass. side) head, to look aged and slightly rusted. Some have suggested coca cola, vinegar ⇦in bulk on eBay or Amazon [affil links] /salt/hydrogen peroxide/water approaches.
I live in Colorado. It has been cold here for the most part during my rusting adventure.
Any insight on how to effectively get the rust to bite deeper into my table would be appreciated.
Thanks.

Kurt Yelek
- Fort Collins, Colorado, United States
December 18, 2012

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Painted Steel With Rust Finish

Q. Hello, I'm putting together some concept marquee signs made of steel and I'm trying to determine the best way to create my paint finish. I want it to have a vintage painted look with various areas that rust is showing through. Would the best way be to rust the steel first, paint over top and then sand off the paint to show through to the rust? Or should it be painted first and then areas chosen to rust through?

 

Please see example photos of what I'm trying to achieve.

Paul W [surname deleted for privacy by Editor]
- Toronto, Ontario, Canada
April 11, 2015

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Q. Hi. I made an outhouse out of old barn wood. Well, I bought unfinished ceiling tiles for the roof and I want to know the fastest and best way to rust them.

Kelly James
- Tehachapi ,California USA
April 14, 2015

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Q. Thanks for all the great tips! Can someone tell me if, after using one of these techniques to rust mild steel, if the poly clear coat sticks permanently to the now rusty steel? Meaning, does the oxidation/rust ultimately dislodge the clear coat and/or create flaking?

Any tips/experience would be great.

Thanks.

David Nielsen
- SLC, Utah, USA
July 18, 2015

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Q. I too am interested in arresting existing rust without removing it AND without darkening its color. I'd like to do this on the outside of an old cast iron clawfoot tub (I like its current corroded appearance, just don't want the corrosion to continue).

The impression I get from this thread is that most of the ways of arresting the rust would also darken it.

And several people attempting protective clear coats seem to have had problems indicating that the rust process was not truly arrested -- I'm not clear whether these objects had continued exposure to water?

I'm wondering whether something like Stops Rust® Matte Clear Enamel Spray would work for me.

I'd greatly appreciate any further advice re: how to arrest rust without darkening it or otherwise changing its appearance!

Carolyn S
- Dallas, Texas, USA
January 12, 2018

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Q. I'm also an artist and have used many of the approaches listed here with good success. Most have turned out quite brownish, though, and I was wondering if anyone can recommend an additive chemical or technique that will produce a much lighter yellowish to red orange rust more closely simulating the colors of Corten steel for example?

Alan Hingeveld
- Whittier, California USA
March 5, 2018

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Q. We want to get some gates made that look old and rusty but don't stain our driveway. The rusting method is now fully understood (thanks to you all), however I'm struggling to know what to do to prevent the ongoing rusting and seal these large gates properly to stop further deterioration. Is the use of Polyurethane sealer the only way to do this? If so, will they need progressive treatments over the years or should the sealing with a couple of coats be lasting?

     

Appreciate any additional information you are able to provide regarding this. Cheers

Liz Green
Botany Bay Design Solutions - Blacktown, NSW, Australia
March 6, 2019

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Q. I need to make a cabinet from raw mild steel and then make it have heavy rust, as if it had been found on let's say an old ship for the sake of discussion. I will make it from probably 1/4" thick steel to allow for very heavy pitting, erosion, etc.. and of course I need to get it done asap. I've used muriatic acid from big box stores for removing rust from heavily rusted and pitted machinery old and I don't think it is strong enough. It would seem like something more along the the line of hydrochloric acid would be what I need. I know someone that has it for putting in cooling towers on large buildings. I thunk I saw a label on it that said it is 92%.
When I get it looking like I want, how do I make it stop permanently? It will be installed in an office with carpet.

Eric Fuller
Custom furniture and millwork - Tomball, Texas USA
February 25, 2020

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Q. Thank you for the advice Ted. The machine parts I cleaned heavy rust off of were mainly table saw tops. Can't get the rust out of the pits by sanding it of course. I have no idea how long they stay looking like that because I cleaned them, put paste car wax on and sold them on complete table saws. I'll give your way a try. I'm looking for really, heavy pitting, like something that has been sitting in water for years. I saved the acid from a car battery once and it wasn't that strong. Guess it's diluted too much with water. Anything I can do to speed up the process or make it more degraded? Salt, bleach, etc... What will happen if I put some of that 92% hydrochloric on it? Is there something stronger to use? Sulfuric?

Eric Fuller
Custom furniture and millwork - Tomball, Texas USA
February 25, 2020

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Q. Yea I'm looking for more than an orange, surface rust like the people here with corrugated metal roofs. I read that nitric acid will dissolve steel and any rust on it. Sounds like I might have to do 2 treatments. One to get all over rust and a second spot treating for pitting, like you said. I might experiment with a piece doing something different. Before any rust accelerator (acid, whatever)using a stick welder set at high amperage, drag a 6011 rod back and forth across the surface. The spatter would melt small pits. Scrape off anything above the surface then make it rust.
Will it stop rusting as long as it's in a climate controlled area (and thoroughly sealed)? If Corten steel will rust, to a point, and then the rust basically seals the rust what's the difference? Metallurgy?
If I sandblast all parts before assembly will that help it to rust faster? Any ferrous metals I have sandblasted, if it will just get clear coat, I have to coat quickly because it starts to rust fast. Even after I clear coat it still gets a faint brownish tint. Doesn't stay looking like it just came out of the blast cabinet. I blast with 20-30 grit glass beads.
No matter what chemicals I use I assume the project needs to be rinsed well with water and dried well before applying sealer. Getting it out of every crack, so sealer will adhere, is tough. That's why I prefer not to use stripper for paints on metal or wood. Too hard to get all of the stripper and rinse agent out of small areas.

Eric Fuller [returning]
Custom furniture and millwork - Tomball, Texas USA
February 26, 2020

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Q. I mixed concentrated nitric acid (1 part) and muriatic acid (3 parts). I put 2 small pieces of hot rolled steel and one grade 8 bolt in it for 2 days. Of course the reaction was very active. Had to mix it in a glass container because I used a metal coffee can previously and it dissolved the can enough to make it leak. I had the can in a stainless steel pan in case the mixture overflowed. After 2 days the mixture was rust colored and there was quite a bit of sludge in the bottom. What is the sludge? Looks like too much to be the black coating you usually see on the outside of hot rolled steel. Is aqua regia useless after its reaction?

Eric Fuller [returning]
- Tomball, Texas, USA
April 11, 2020