Preserve the Beauty of Raw or Rusted Steel & Iron Surfaces

Picture of Preserve the Beauty of Raw or Rusted Steel & Iron Surfaces
I see many ibles made with black pipe here but rarely do they mention any coatings to prevent rusting. I also often build with rusty items where I need to cover the rust so it won't rub of on clothes etc. but don't want to lose the beauty of the patina. An architect once told me he used linseed oil to preserve rusted iron outdoors. I tried it but the damned stuff never fully dries! I could use polyurethane but the oxidation will continue underneath and it will eventually flake off. I've tried "rust stabilizers" but they turn the rust black so it loses it's color. I finally got turned on to a product from an old timer in a paint store I would probably never have found on my own.
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Step 1: Penetrol

Picture of Penetrol
He recommended a product called Penetrol normally used as a paint additive to improve flow and adhesion that also seals and stops rust. It can be used alone as a base coat on bare metal and will fix the rust while preserving the appearance. The finish will be darker than dry rust but similar to rust sprayed with water or oil and can be top coated with a polyurethane for a more durable finish.
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BrianJewett (author)  Keegan McClain2 months ago
Hmmm... It looks like a question I got in my e-mail has been removed but it you were still wondering, I'd wipe the panels down with mineral spirits or alcohol to remove any oils ant then either use the Penetrol & polyurethane top coat or since there's no rust on the new panels, you could seal them with a paste wax. This looks like naked steel but still seals the surface to prevent rust.

Thanks for the help Brian. Here a pic of the new Design area at Noble Plastics. The renovation is not done, but the walls in the design studio look and work great!


I'm working with Keegan on this project. How much area can we expect to cover with 1 gallon of the Penetrol?

Also, can you recommend a matte polyurethane top coat? Does it matter if it is oil-based or water-based?

trishbohr16 days ago

Hi, I bought 90' of antique iron fence panels. They have been stored outside for years and are pretty clean but have surface rust. I love the aged appearance and It sounds like Penetrol might be a good option for me. I don't want the structure to rust away. Do you think Penetrol would work to preserve them and would you apply a sealer to finish them and protect them from the Midwestern winter?


Trish Bohr


BrianJewett (author)  trishbohr16 days ago
I don't have any experience with long term weather exposure so I'm not sure. I think the Penetrol is linseed oil based with hardeners. You may be better off without the polyurethane over coat outside so you can just re-coat them periodically without sanding. If you have a really good paint store (not just a hardware store) in your area they might be able to answer this better than I can.

Thanks Brian. I sanded and used Penetrol on a 10' panel today and love the look. I rubbed the Penetrol on with a cloth glove and it covered easily so re-coating wouldn't be a big deal. I appreciate your help!

BrianJewett (author)  trishbohr15 days ago

You probably don't need to sand. Just knock off the loose rust with a steel wire brush, then clean the dust off with a hose and let it dry well. Wire brushing will get into the low spots better and won't change the surface texture.

A little hard to see, but in this picture the front panel has been treated and the others have not. I actually didn't sand, I used a wire brush on my drill to remove the rust then applied the Penetrol. I'll attach a better before/after pic when finished. Thanks again!

Hotpickle2718 days ago

I'm attempting to make matching (w/cut out pattern) candle holders and light sconces out of rusted / reclaimed tin cans and duct metal. I am wondering if the Penetrol & Polyurethane treatment would be safe to use when adding the heat of a candle or lightbulb??

BrianJewett (author)  Hotpickle2718 days ago
I would think so, but I've never done a burn test on either material. As long as you're not exposing the coated metal directly to the heat of the flame I don't think there's be an issue. Like almost any paint or coating, if you put it in the fire you're probably going to ruin the finish and create some nasty fumes. Test your application outside in a safe area if you have any doubts.
bmehl1 month ago
I'm fabricating a steel/wood bar and want to keep the raw steel look. The top is 10GA plate that meets up with reclaimed beams that make up the bullnose. The bulk of the bar will have to be built inside the restaurant so I may not be able to spray on polyurethane. The bar will see a ton of traffic. I considered the penetrol then a few coats of wipe on poly. What would you recommend? Penetrol / poly? Johnson paste wax?

BrianJewett (author)  bmehl1 month ago
I don't think the wax will hold up to the heavy wear. Even Polyurethane might not be up to the task unless you are willing to embrace scratches etc as patina. I think powder coating needs to be sandblasted but I'm not sure. It's pretty tough and available clear. You might also consider a heavy resin coating. You don't need the Penetrol if the steel is new and rust free.
C57Acuna1 month ago

I'm hoping your method of Penetrol/polyurethane will work on this rusty antique iron bed I found recently & want to use in a bedroom of my 1930 home. It had some flaky, bright gold paint, which I've gotten off. It's covered in rust, which I'm in the process of getting off. I'm kinda liking the metal color that's emerging and would like to preserve it, Hours of research have only resulted in ways to paint. Will the Penetrol turn it all black? I want to keep it it's own color as much as possible. I've all ready spent more on fixing it up than I did to buy it. I'm looking forward to hearing from you. Thanks.

Bed- rusty anique iron bed   2.14.jpgBed- getting the paint off   2.14.jpgBed-  getting the rust off   2.14.jpgBed with supplies   2.14.jpg
BrianJewett (author)  C57Acuna1 month ago
The penetrol will not turn the rust black. It only darkens it the same way as getting it wet does. This is a perfect application and exactly what I've used it for.
Great. I'm hoping to finish it this week cuz I've got guests coming Friday & right now the mattress is on the floor. Thanks.

We are installing raw steel sheet metal panels to use as magnetic pin boards in my office. We want to keep the raw metal look, but not the hand prints from installation. What would you recommend I do to remove undesirable hand prints before the applying Penetrol? Or is this something that will not show up?

Aucapucin4 months ago
Nyalic clear surface protectant is great for sealing in rusted or bare metal surfaces, patinas, etc, and it protects them too. It will also prevent tarnish of metals and stop fingerprinting on shiny surfaces. The results will last years but you can remove or repair the coating easily, too.
BrianJewett (author)  Aucapucin4 months ago
Do you have personal experience with this? From what little I was able to find, it looks like it's just for hard, clean smooth surfaces. I saw no mention of being able to use it to preserve rusted or corroded surfaces. It also sounds like pretty nasty stuff to use and not very hard or abrasion resistant.
ebehan4 months ago
Thanks!! Can't wait to use this on this piece to keep it looking like I found it!
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BrianJewett (author) 5 months ago
I should mention that after 3 years the area on one of these sinks where a soap bottle sits, has sprouted some fresh rust. I probably should have done 5 or six coats of poly instead of just 2 for a bathroom counter top. I should also find a better way to dispense soap in the bathroom.

I have a natural aversion to letting water stand anywhere. I have to wipe it up. It's just my nature. I treat these industrial steel counters like they were hand rubbed walnut. My wife, however, is not burdened with my affliction. She first wets her hands thoroughly, then without even a moments hesitation
, goes straight for the soap pump and leaves it sitting in about a tablespoon of water. Pair this with the fact that she's a fiend about washing her hands every time she goes near the kitchen, and you have the soap dispenser pretty much sitting in water for 3 years straight. So, even though the soap bottle is plastic, it's wet and being pushed down on a dozen times a day. In retrospect, it was obviously too much to expect from 2 coats of polyurethane.
Hi, I have an early 1900s cast iron and steel apothecary cabinet (glass door and sides). I stripped all paint with something like Stripeze and rinsed with mineral spirits/paint thinner, but it keeps rusting. I'd like a gray, gunmetal appearance. Do you think this product would work? If so, any ideas on how to get the rust off (powdery, like if you didn't immediately dry a cast iron frying pan) first?


Houston, TX
BrianJewett (author)  hathawayfarm4 months ago
Naval Jelly will take the new rust off. If you actually remove all the rust you won't need the Penetrol. Spray on a few coats of polyurethane to seal the surface and preserve the raw steel look. Don't brush it on. The brush marks will stick out like a sore thumb on the flat steel surface.
Ok, this is great info. And I get what you say about being sure to spray the poly. Do I rinse the naval jelly off with water? Will that make it rust again? Or should I just wipe off the naval jelly?

Can't wait to get this cabinet finished and back in the house!

BrianJewett (author)  hathawayfarm4 months ago
The water will only create rust if you leave it on the metal. I haven't actually used naval jelly since I was a kid (40-50 years?) I seem to remember it getting rinsed with water but follow the instructions. Just wiping it may leave a residue that could cause problems with the new finish. To thoroughly remove any water afterwards, I'd towel dry and then follow up with a hot air gun, blow drier, torch etc to warm the surface and be sure any water in cracks and seams is evaporated. Then coat it right away to seal the surface so it doesn't rust again.
pdub775 months ago
This is exactly what I was looking for! So glad the bot didn't bump you off for good. Thanks so much!
BrianJewett (author) 5 months ago
I don't know about other metals but for steel or iron, penetrol is a rust converter, It chemically changes the iron oxide to a different compound and stops the corrosion. If your patinas are corrosives that actually cause oxidation of your base metal it may work. If they are just color coatings I don't know if it will have much effect.

The penetrol itself isn't that hard. That's why I suggested a topcoat of polyurethane. Jewelry is a pretty tough, high wear application. You could experiment, but I'd also check with other jewelry makers or materials suppliers and see what they think about the specific materials you're working with.
oh my gosh, i really needed to read this. this has been an endless search but let me see if you think it may work for me. i make jewelry with a patina and all of my coatings have either come off or changed the color of the patinas causing the patinas to come off within months. you are saying i can put this directly on the finished piece and it will seal the color, then put another sealer on top of it? if so, what would prevent the final coating to not rub or wear off as before when used without the penetrol?
BrianJewett (author) 5 months ago
Which ever brand you like should work fine.
manyon5 months ago
Great write up Brian. What kind of polyurethane do you use over the penetrol?
WOW! Thanks a million! Your advise/endorsement was most helpful. This looks to be exactly what I need to use. I can't believe that I did not come across this more quickly in my seemingly endless internet search. (Thanks to Brooke at for leading me your way!) I am so pleased to see that you used it for preserving the natural state of the metal including the look of the rust, you gave me a true testimonial for my endeavor.
I was given an old camel top trunk that I want to use to store/display quilts but I need to find a way to seal the rust on the steel. I don't want to take all of the rust off b/c I want it to have that look, but want to seal it in some way so it does not rub on and ruin the quilts or carpet.
Schmeebs1 year ago
Would you recommend treating a raw steel bicycle frame with this product? I love the look of the rust on my frame, but I don't want it to be structurally compromised. Let me know what you think. Thanks, great post!
BrianJewett (author)  Schmeebs1 year ago
I don't know how durable the penetrol would be on it's own but I'd think it would be fine with a couple of top coats of a good clear coat like polyurethane.
I tried this with a gloss polyurethane topcoat over a steel sculpture meant for indoors. I love the results. I want to wait a year and see what it looks like then. I have an idea. How about sealing the penetrol sealant with matt or satin polyurethane and applying metallic or earth tone acrylic paints over it to accent the rust finish then sealing it all off with Rustoleum clear coat? That would be a reasonable way to modify the color of the rust to your liking. A few dry brushed streaks of yellow ochre acrylic can bring back lighter tones lost by the penetrol wetting the rust.
BrianJewett (author)  soapmaker721 year ago
You got me. I don't tend to use paint much. I'm usually more interested in preserving the patina and the visible history of things. It's an interesting idea though. Give it a shot and let us know how it works out.
kozolchy1 year ago
Great guide! I'm wondering how long do I have to wait between the coat of penetrol and putting the mat polyurethane top coat on?

BrianJewett (author)  kozolchy1 year ago
I don't recall off the top of my head, but whatever the can recommends.
femoody11 year ago
I just found this site and love it! I am not a professional anything other than retiree. I have built a small pavillion on some property I have. I want to incorporate some rustic (and rusty) wrought iron cemetery fence in the project and I am worried that since it it outside and a blowing rain may cause the rust to drip down on the textured, stained concrete floor. I have read the above comments and wonder if just plain polyurethane would work sprated on over the rust would work or if the Penetrol should be applied first. Also, how much prep should be done on the rust? Thanks for any comments, Fred.
BrianJewett (author)  femoody11 year ago
Just encapsulating rust won't stop it from progressing and the coating will eventually flake off. The Penetrol will soak in and convert the rust and stop the process. The poly can go on over the Penetrol.

As for prep, just make sure the surface is clean and dry. If it's a really old piece of iron, it probably isn't flaking any more. I'd probably just scrub it with a bristle brush and maybe some water if needed and let it dry thoroughly. I would not do any sanding or use a wire brush as they could remove the rust you seek to preserve or ruin the patina.

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