Is POR-15 better than a rust converter?

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A huge number of rust converters are there that claim to prevent oxidation by changing the nature of rust and corrosion.

Can those rust converters really change the nature of rust and corrosion? Unfortunately, they can’t.

Almost 99.9% of the rust converters available on the market only block a momentary intervention of rust and corrosion by creating a coating on the rusted surface.

Over time, the layer gets weakened and rust again starts to take over its position on the metallic or concrete surface.

The effectiveness of a rust converter can be thus defined in terms of how long the coating can block rust intervention to the surface.

What I am here to discuss?

One of the best rust preventive paints available on the market is POR-15. If you are asking how POR-15 is different from other rust converters, this might be the article you want to read.

Before you start, I would love to mention that whatever I am about to share is my own personal experience and a little bit of my research on the topic.

However, the extract that I am about to share includes both positives and negatives of POR-15.

Without wasting any more of your time, let’s get into the discussion-

Rust converter vs. Por-15

what is a Rust converter?

A rust converter is a water-based chemical solution that converts rust into another chemical compound. However, a rust converter is not a permanent rust preventive solution.

Regular usage of a Rust Converter can prevent rust and corrosion from getting back on the surface again. It basically creates a layer on the corrosive surface to prevent the building of rust on the surface again.

In general, a rust converter has two main active ingredients to get the job done.

  • Tannic acid or phosphoric acid
  • Organic polymer.

How does a rust converter work?

Rust is a type of chemical reaction that happens when moisture or water reacts with Iron. In the language of chemistry, we call it an oxidation reaction where an atom loses one or more electrons.

As the output of the Oxidation reaction, we get iron Oxide, which ultimately causes the metal or iron to rust.

Here is how a rust converter ensures protection against moisture-

  • Tannic acid or phosphoric acid reacts with iron oxide.
  • Tannic acid transforms iron oxide to iron tannate.
  • Phosphoric acid transforms iron oxide to iron phosphate.
  • Both turn into a stable black-colored coating.
  • The organic polymer provides a protective primer layer.

what is por-15?

Por-15 used

POR-15 is a rust preventive paint solution that can be applied directly on rusted or seasoned metal surfaces and concretes.

According to the manufacturer details, POR-15 is a non-porous coating that shows enough resistance to water and many other chemicals that can react with metals and irons.

Why is por-15 different than a rust converter?

As I have mentioned earlier that rust converters are not a permanent solution as over time the coated layer gets weakened due to exposure to water and other chemicals.

POR-15 is different because instead of trying to change the chemical properties of rust, POR-15 tries to block the intervention of water to the rusted surface.

That means POR-15 prevents rust mechanically not chemically.

POR-15 is actually applying the ‘prevention is better than cure’ formula which makes POR-15 a bit different and more effective than most rust converters.

Comparison between rust converter and Por-15

Rust converter


A chemical rust preventive solution

A mechanical rust preventive solution

changes the chemical structure of rust

prevents water or moisture intervention

Contains phosphoric acid and organic polymer

Contains zinc phosphate and phosphoric acid

The chemical bond may break due to direct exposure to UV-ray

Better protection against UV-ray

Multiple  coatings on the surface are required

Two coatings on the rusted surface are recommended

Not a permanent solution

Not a permanent solution

Por-15 Rust Remover

How to use rust converter?

Rust converter basically converts the iron oxide into a stable chemical reaction and removes the rust. However, you need to know that it is only a temporary way to remove rust from the metal surface, not a permanent one.

However, you need to prepare well including the pre-cautions and apply the coating accordingly to get the intended result out of it.

Two things you can do as precautions, which are –

  • Wear safety glasses.
  • Wear safety hand gloves.

When you are safe enough with your preparations, you can move on to the work that begins with the cleaning of the metal surface.

  • Use a brush to clean the applying surface.
  • It will remove the loose rust from the surface.
  • Wipe on the surface thoroughly once.

After removing the extra rust that was loose and any other contaminants from the surface, you can apply the coat. However, you can either go for a paintbrush or sprayer for this.

  • Take an extra container.
  • Pour some of the coat into the container.
  • Apply the coating on the surface slowly using the brush.
  • Let it dry for up to one hour.
  • After one hour, it will get ready for the second coat.
  • Apply the second coat in the same manner.
  • Let the second coat dry for 48 hours.
  • Then, you can put on any oil-based paint on it.

However, you need to know that two coats are enough when you are applying the converter using a paintbrush. Meanwhile, three or four coats are necessary while using a sprayer.

How to apply Por-15 on any object?

For a long-lasting solution from rust on iron, steel, or any metal products, Por-15 offers the most effective service. However, to get the most out of it, the coating requires metal prep before topcoat after coating.

Applying POR-15 on a rusted surface isn't a tough task unless you know the right way to do the job. We've categorized the entire coating process into four sections.

  • Cleaning the surface.
  • Metal prepping.
  • Applying the coat.
  • Applying the topcoat.

Cleaning the surface

A Por-15 cleaner and degreaser is necessary to clean the surface properly before you begin the metal prep. Here are the steps to follow.

Using cleaner and degreaser means removing any kind of contaminants on the applicable surface, which can affect the rust preventive coating and not provide the intended result.

  • Wear safety gloves and glasses as pre-cautions.
  • Apply the cleaner or degreaser on the surface.
  • It's better to do it with a sprayer.
  • Let it dry for a few minutes.
  • Wash the surface with clean water.

Metal prepping 

Metal prep is necessary to create the perfect surface to apply the coating and let it stay here forever. It has zinc phosphate and phosphoric acid that chemically reacts with the metal surface.

If somehow the applicable surface stays shiny or unsuitable for applying the rust preventive coat, the project might fail. It drops the zinc phosphate coating and etches the surface ready for applying the coat.

Here’re the steps to follow.

  • Apply the metal prep using a sprayer.
  • Continuously spray on the surface for up to 15 minutes.
  • Don’t let the prep dry on the surface.
  • It will create a zinc phosphate coating.
  • Wash it with clean water.

However, before applying any metal prep it’s necessary to keep in mind that it doesn’t have any harmful objects that can damage the surface.

Applying Por-15 coating 

Here comes the big part of the project where you’ll be applying the rust preventive coating on the metal prepped surface.

Basically, you need to have a couple of coats on the metal surface before applying the topcoat. However, applying this coating is a lengthier process as well as you have to wait until the first coat dries before applying the second coat.

Here’re the simples steps you can follow.

  • Pour some of the coatings into a container.
  • Use a roller brush or paintbrush.
  • Put on the first coating slowly using the brush.
  • Let it two to three hours to dry.
  • Now, pour more coating into the container.
  • Apply the second coat in the same way.
  • It can take up to six hours to get properly dry.

Apply the topcoat

The last but not the least stage of applying Por-15 coating is applying the topcoat. Although it's a rust preventive coating, it can still break down due to elements like UV-ray.

And that's when you need a topcoat over the two layers of coating to make it permanent and prevent the breaking of the anti-rust layer.

Things to keep in mind before applying POR-15 

  • Remove rust converter coat before applying.
  • Coming in contact with elements can bring back the rust.
  • Two coats of the Por-15 are enough.
  • Necessary to have metal prep before applying.

Three more POR-15 products that will make the job easier are-

  • Por-15 cleaner and degreaser
  • Por-15 metal prep
  • Por-15 topcoat.

Cons of POR-15

  • The presence of humidity in the environment can make the paint job harder. Choose a hot and dry day instead.
  • Removing the paint from the skin is quite hard. Wear gloves if you want to prevent such obstacles.
  • POR-15 won't bring a greater result if you skimped on prep. Prep is everything. Give a bit long more time on prep.

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