Preserve the Beauty of Raw or Rusted Steel & Iron Surfaces





Introduction: 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.

Step 1: 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.

Be sure to open and view the rest of this ible before sending me questions. ;-)

Step 2: Obey the Bot

(I originally made this a single page post since it's basically just a product recommendation but "the Bot" didn't like that. It yanked the post and sent me a note to mend my ways. So... I chopped it up and added some numbered steps. Hope it stays put this time. ;-)

1) I usually wipe down the piece with paint thinner to remove excess dirt and oil but since the product is oil based you don't need to remove every last trace. For a rusty surface I'll usually clean it real good with water and a soft brush or cloth to get any dirt off. In the case of the steel vanity tops shown in the intro I left one out in the rain for a week to cover some scratches and wanted to preserve the light layer of rust. I just rinsed it off with a hose on saw horses, let it dry in the sun then

2) applied the Penetrol with a brush. Even on the perfectly flat surface it didn't leave brush marks.

3) I always spray on a mat polyurethane top coat or two for a smooth finish and the finished piece looks completely natural.

I've used this method for several years now including on towel bars hung with damp towels everyday and for a countertop under my bathroom sink. So far they look just like the day I finished on all my projects.

Step 3: Answers to FAQs

The reason I use the polyurethane top coat(s) is that the Penetrol is a linseed oil product, and as such, is not very hard or durable. The polyurethane is a good, stable, long-lasting finish that won't easily wear off.

I've also been getting a lot of questions about clear, un-rusted metal. I wrote this about protecting and preserving the rust for it's looks. But if you don't have rust, you can skip the penetrol and just go straight to the polyurethane.


I'm just a guy who, by chatting with an old time paint guy, stumbled onto a way to stabilize and preserve rust without hiding it. please don't ask me how to repaint your car or patio furniture. I don't know. This post is only about preserving the beauty of rust while stabilizing it to make a rusty object useable and not so messy.

A table top, specially a work table or dinning table, is a pretty tough environment. It's prone to lots of impacts and abrasion. At the least, you should use several coats of polyurethane. You might also talk to someone at a Sherwin Williams store about SherClear. It's a HD industrial clear coating. It's pricey ($100/gal?) but incredibly tough. It's made for ships and equipment but a friend uses it to coat canvas floorcloths and says it lasts for years in high traffic areas and under tables and chairs.


If you already have an oil base coat like Penetrol, you can only use an oil based product on top of it. Remember that oil floats on water. You can use oil OVER an water based coating but not the other way around. The reason is that oil based coatings don't set up completely hard but remain somewhat flexible. Water based products set up hard and inflexible and will eventually flake and peel on top of oil based coatings.

4 People Made This Project!


  • Casting Contest

    Casting Contest
  • Woodworking Contest

    Woodworking Contest
  • Oil Contest

    Oil Contest

We have a be nice policy.
Please be positive and constructive.


2 Questions

Please tell me the brand of poly that works over the penetrol. The paint stores will not recommend one. Thank you.

We painted bare steel panels with Penetrol to seal and stop rust. Works great but leaves a pretty high shine. I just used Zar Ultra oil-based polyurethane Clear Antique Flat over the penetrol (did not sand). Turned it into a beautiful flat finish. Very happy with it. It seems durable. Only time will tell.

1 more answer

Any oil based paint or coating will work over another oil based coating.

Nice project!

SherClear seems to be acrylic and not polyurethane.

Did you mean SherThane?

We have a patinaed steel countertop to seal with a matte clear but not sure what to use. Thanks!

I didn't know SherClear was acrylic. don't use acrylics (water based) over oil based coatings.


I made this sculpture out of railroad spikes about a year ago and put two coats of penetrol on top of the Rusted railroad spikes and had then set the sculpture outside in North Florida with this very corrosive environment and the penetrol has completely preserved the metal . unbelievable! I threw in a couple pics of more rusty metal pieces preserved with Penetrol....that stuff works!
Off 'Da Chain Metalworx....Panama City Beach Florida

IMG_20171225_072917_811 (1).jpgIMG_20171225_072917_817 (1).jpgreceived_588923234776705.jpeg
1 reply

Thanks Susan! I get frequent questions about outdoor durability but all my applications have been indoors.

My new outdoor table is of a painted metal. I have used Penetrol in the past which is great but it leaves a shiny finish. I was hoping there is a product that produces a dull finish. Is there such a product? Many thanks.

4 replies

You can also change the gloss level with very fine steel wool. Pass over the table in many different directions, without pressing too hard. The microscopic scratches left behind will not be enough to damage the coating, or to make it non-transparent, but will take away the gloss.

If your table is new and painted, there's no need for Penetrol. You can change the gloss level with a clear top coat of polyurethane in flat or satin finish.

Thank you Brian, will give it a go!

Thank you Brian, will give it a go!

Love the instructable. Wish I had found it years ago when I was doing way more with rusted metal. Quick question about the poly though, do you use brush on, wipe on, or spray on? I use a thinned wipe on poly very frequently with my wood working projects but worry that the mineral spirits will ruin the penetrol.

I have a fully patinaed light gauge sheet steel tray from an old scale. Well let's call it fully rusted. I want to preserve the patina however it is extremely rough in texture. The item will remain outdoors subjected very close proximity of growth media. plants, and water.

Suggestions in products and procedure?


I've just installed an old unfinished iron sink in my kitchen and am trying to figure out how to keep the rust down....beeswax? lanolin? olive oil? Any ideas?

1 reply

I've never seen or heard of a raw, uncoated cast iron sink. It's a very tough environment which is why they're always enameled. I'd suspect it might be one from a factory that never got coated or maybe someone stripped the glass enamel from it? Anyway, I wouldn't think of using it in my own kitchen. Any coating I could think of would probably need very frequent reapplication.

hi there. I was wondering if this product will work on tin sheet panels on an antique steamer trunk. It is covered in rust and I'd like to preserve the color but stop the rusting process.

1 reply

Yes. If it rusts, it's iron based and this will work.

Brian, I'm making a countertop for a bathroom and was wondering how you made the countertop in the picture right below the 'obey the bot', the non rusted one. I have the steel already made but there are some scratches in the surface as well as rust we want to remove. What would you recommend for rust and scratch removal? It looks like naval jelly may be the best (non marking) way to remove the rust but I'm not sure about the scratches. Should we let it sit in some water to 'rust fill' the scratch so to speak and then seal just the scratch area with some penetrol?

Also i think we are going to use the Sher-clear HD clear coat to seal it since this will be a highly used countertop. Do you think that may be the best bet or should we just penetrol the whole thing and then just use some clear matte oil based poly to cover.

1 reply

Don't know about removing rust. I always want to preserve or encourage it.

As for removing scratches, you can't, and still preserve the raw steel finish. All you can do is add more marks in a hopefully authentic way to camouflage or help them blend in. Consider your approach carefully because you can't "undo". Be careful not to make it look phony like those dopey looking "pre worn" jeans.

If you don't like your results, all you can do then is go for a different finish with a sander or sand blaster, paint, etc.

would this work on cast iron radiators? about to have mine sand blasted clean and didn't want to paint them because i like the raw iron look. we run them at lower temp 140 - 150 degrees.

2 replies

I would think so but as I've said many times, I'm not a paint specialist. In the grand scheme of things, anything under the boiling point of water isn't really all that hot but you should check with a good paint store about the appropriateness of any coatings for higher temps that could promote of gassing.

thanks for the reply!

Could you give me a call mate, got a few questions and was thinking you might be able to help me out- 0452516119

Hi Brian et al,

I want to install a galvanized steel shelf as a kitchen/breakfast bar in my home (between kitchen and dining room--the stove is on the opposite wall so it would not be affected by direct heat). Would the penetrol stop the sheet from rusting? I am more interested in preventing rust than in preserving it.

Thank you!