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How To Remove Rust From Metal

Painting Wrought Iron Fence? Learn How To Remove Rust From Metal

One thing is for certain, an ornamental wrought iron fence has a regal look that really compliments a historical home.  Perhaps you may have seen one in older neighborhoods in and around Atlanta.  These fence panels were hammered and rolled by blacksmiths while the metal was hot.  This was a labor-intensive process that hasn’t been done on a commercial scale since the 1970’s.  The traditional style has always been to paint wrought iron fences black.  However, over time they can become covered in rust if they are not properly maintained.  Something to consider when planning your next exterior painting project.

wrought iron fence

Styles of a Wrought Iron Fence

Each wrought iron fence has a unique custom design.  Notable features can include decorative collars and bases that cover the welding marks that connect different shaped balusters and posts.  Within each section of fence or gate door you may have features such as rosettes, panels, plaques or corner castings.  Balusters may be adorned with a decorative fleur-de-lis, spear, finial or cap.  The more detail a fence has, the more likely moisture will puddle up and start to rust the wrought iron fence over time.  Paint your wrought iron fence with a rust inhibitive paint to protect against corrosion.

wrought iron fence

Types of Metal Fences

Newer homes may incorporate a metal fence to outline their landscape as well.  The benefit of a metal fence is that you can contain pets or small children within the yard without obstructing the view.  A popular choice for metal fences is aluminum because it is easier to maintain since it does not rust.  However, it doesn’t have the same look as the traditional wrought iron fence.

Traditional style fences are now made of mild steel that is cast with a small amount of carbon to give it more strength.  These steel fences can replicate that traditional ornamental look or have a sleek modern design.  The same can be said about entrance gates and porch handrails.

How Do Metal Fences Rust

Regardless of the style or whether a fence is made of wrought iron or mild steel, rust can still be an issue.  Rust is created when iron molecules are exposed to water and oxygen which forms iron oxide, the chemical term for rust.  For this reason, all ferrous metal fences must have a mechanical barrier of primer and paint to protect the iron from that exposure.  Not only does iron oxide degrade the structural integrity of the metal but it also looks unsightly.

Therefore, it is important to maintain your iron fence, gate and handrails.  Eventually the paint will break down from the elements and chip away.  Once the rusting begins you are now faced with a more work intensive task of removing all the rust to prepare for new paint.

How To Remove Rust From a Wrought Iron Fence

There are three common techniques that can be used to eliminate rust from your iron fence, gate or handrails.  The first is a process called chelation.  The second option to consider is converting the rust to another substance.  And a third alternative is dissolving the rust completely.

rust removal products


The process of chelation can be achieved by using a product like Evapo-Rust which is considered a chelator.  Chelators contain compounds like EDTA (edetic acid) that attack iron oxide (FE2OH3) by breaking up their chemical bonds and creating new bonds with the iron ions.  The result forms a soluble that can be rinsed off leaving less rust than before. 

This technique was first invented in the 1950’s as a dietary supplement technique to remove metals from farm animal feed.  Benefits of using this method are that it is eco-friendly and safer because it is non-toxic and won’t kill the grass or contaminate the soil.  You can also eliminate the risk of damaging good iron that is not rusted. However, it works best if much of the heavy rusting has been brushed off or sanded first.  It is important to prime the metal on the same day of using the chelator.


Rust conversion is achieved by using products that contain tannic acid or phosphoric acid.  One example is a product called Ospho. Tannic acid reacts with the iron oxide and converts into a material called ferric tannate.  Likewise, phosphoric acid reacts with the iron oxide and converts into a material called ferric phosphate. Both ferric tannate and ferric phosphate are porous bluish black materials that remain bonded with the iron.  They can then be physically removed or left on as a primer and painted over. 

Rust convertors work best when trying to restore metal that is completely covered in heavy rust.  However, if used on bare metal it could flash rust.  They also may not work well on mixed surfaces of original paint and rust because there is a chance that they might not fully cure. You must first sand down and scrape off loose paint to make sure all rust is exposed to the product.  Another downside is that conversion process must be allowed 24 hours to take place before painting.


Rust dissolvers work similar to the chelators in that they form an iron soluble that can be rinsed off with water.  The difference is that the soluble is created from a chemical reaction instead of a shifting of molecular bonds.  One example of a rust dissolver is a product made by Loctite called Naval Jelly.  It contains a gelled phosphoric acid that can be brushed on to rusty metal and should be rinsed off in 15 minutes.  It seems to work best if some of the heavy rust is already brushed off or sanded first as well.

Which Type of Rust Removal Product Is Best?

Therefore, depending on your situation and project schedule, you can decide which method works best for you. After you have completed all of this hard work it is important to use a good metal primer as soon as possible.  Rust inhibiting primers like Kem Kromik include phenolic alkyd resins that are more resistant to corrosion.  This product requires 36 to 48 hours of curing time to be most effective prior to applying a top coat.  An ideal topcoat would be Sherwin Williams Direct-To-Metal Alkyd Enamel.  You can go with the traditional black or choose a different color all together.  A semi-gloss or flat finish are both acceptable options.

Professional Painter For Wrought Iron Fences

If you have a wrought iron fence, gate or handrails that need repainting and you would prefer a professional to do the work, then contact Swell Contractors for a free estimate.  We have the experience and the tools to do the job right and guarantee your satisfaction.  Learn more about our fence painting services and if you have any questions be sure to contact us.