Rust Converter FAQ’s

What is a Rust Converter?

The majority of rust converter products that are readily available are a water-based converter and primer in one. Most contain two active ingredients, they are Tannic acid and an organic polymer. Tannic acid, reacts with iron oxide (rust) and chemically converts it to iron tannate, a dark-coloured stable material. Tannins are a group of water- and alcohol-soluble natural products extracted from fruits, trees and grasses. When you purchase new timber you will notice over the first few months the tannings will bleed out. The second active ingredient, 2-Butoxyethanol, is an organic polymer that dries to provide a protective primer layer. This chemical reaction converts the rust into a black protective polymeric coating that is now stable and creates serves an excellent primer for both oil and epoxy based paints.

Rust Converter

How Rust Remover Works

Rust converters produce a chemical reaction that reacts with the rust to produce a black inert substance that can then be over painted. The black coating will help prevent air oxidising the surface of the metal further preventing new corrosion.

What Objects Can I Use Rust Converter On?

Rust Converters are suitable for use on any ferrous metals, iron or steel object such as a rusty car or other vehicles, trailers, fences & gates, iron railings and staircases, sheet metal, cast iron, outsides of water tanks, lawn mowers, boat decks, farm equipment, tractors etc. They are not suitable for use on aluminium, copper, stainless steel or galvanized metal.

How Do I Prepare The Surface for Application?

For the best quality results a good surface is important and Promain as well as leading paint manufactures such as PPG will always recommend the use of sand Blasting. Sand blasting will remove the rust and provide a sound clean surface.  If this is not possible then remove any lose rust with sand paper or a wire brush in an electric drill will allow the converter to work effectively and produce high quality result.  Do not remove all of the rust (this defeats the purpose) as Rust Converters chemically bond to the rust and seal it in. However, they are unable to penetrate grease or oil, so remove clean and degrease the surface first, then let it dry.

Cleaning the surface will ensure that other surface contaminants do not interfere with the reaction of the rust converter on the rusted surface. If the surface is prone to salt water spray or de-icing salts, rinse the surface thoroughly with clean water, and allow it to dry prior to applying Rust Converter.

How is Rust Converter applied?

A brush or a roller are the best method of application. Use a brush for smaller applications and a roller for larger surfaces. For large areas you can also use an airless sprayer.

Can I Apply Over Non-Rusted Or Painted Surfaces?

Rust Converter will adhere to non-rusted or painted surfaces but it does not provide any additional rust prevention when used on these surfaces. We do not recommend application to powder coated surfaces.

Does It Require Thinning?

Apply Rust Converter neat from the tin and not thinned with any products such as white spirit, water or methylated spirits. We recommend to shake or for larger tins stir thoroughly with a paddle mixer before application.

What is the coverage rate?

FLAG RC1 Rust Converter has a theoretical coverage rate of 8-12 m2 per litre for mildly rusted surfaces. Porous, textured and irregular surfaces may require more than one application.

Can I apply a primer coat over Rust Converter?

An oil based primer such as Rustoleum Combicolor Primer may be applied over most water-based rust converters but is not necessary required.

 Is It Necessary To Apply Paint Over Rust Converter?

Although it’s not required, if your surface is exposed to the elements, Promain would highly recommend applying two coats of a quality oil-based paint such as Centrecoat Fast Dry Gloss over the Rust Converter. It will definitely extend the life expectancy of the substrate from adverse weather including rain, salt mist and direct sunlight.

What Type Of Paint Should I Use To Cover The Rust Converter?

Use oil based or epoxy paints to paint over rust converters. Do not use paints that contain hot solvents such as xylene or paints containing Xylene Latex. Do not overcoat with water based paints either.

How Many Coats of Rust Converter Should I Apply?

Many applications require one coat. We however suggest applying a second coat to assure complete coverage and conversion.

How Long Does It Take Rust Converter To Dry?

Most converters such as the FLAG RC1 will be touch dry in approximately 20 minutes. The application of a second coating will ensure complete rust conversion and provide a sound surface for the application of a paint coating.

Overcoating requires a minimum of 6 hours before applying a second coat of Rust Converter. This is to allow for curing. If applying an oil-based top coat, allow a minimum of 48 hours to allow for full cure before applying paint.

How Should I Clean My Application Equipment After Applying Rust Converter?

Simply use soap and water for clean-up of your brushes etc.

Can I Use Rust Converter On My BBQ Grill, Cast Iron Wood Stove, Engine, Boiler, Or Any Other Surfaces That Become Hot?

Rust Converters are not heat resistant. Do not use on any surface that will have heat on it.

Can Rust Converter Be Used On Galvanized Steel?

It’s only effective on the highly rusted areas where iron oxide (rust) is present. It will not bond effectively to the galvanized areas. We would recommend that the rust is removed and a product such as Zinga is applied instead.

Can Rust Converter Be Used Inside A Tank?

We do not recommend using Rust Converters inside water tanks. This includes other tanks that contain liquids such as petrol. You do however use rust converters on the outside of these tanks prior to a coat of paint.

At What Temperature Can I Apply Rust Converter?

Apply these products when the temperature is above 10°C. It’s best to avoid applying in direct sunlight or when the relative humidity is above 85%. Do not apply if the surface temperature is cold or damp.

Which Protective Equipment Do I Require?

Skin irritation is a risk. We recommend to use suitable PPE such as either safety glasses or goggles. We also recommend the use of chemical resistant gloves.

How Should I Dispose Of Any Unused Rust Converter?

Contact your local regulatory agency to determine the proper method of disposal.

Is Rust Converter Harmful If Ingested?

Yes, Rust Converter contains tannic acid. You should immediately get medical attention.

Are Vapours From Rust Converter Harmful?

The vapours emitted are similar to latex paints and are not harmful. We recommend that you only apply these products in well ventilated areas.

Food Contact

You should not allow Rust Converters to come in contact with foods or fresh water supply.

Can I Put A Powder Coat Over Rust Converter?

Promain does not recommend using a powder coating over the rust converter. We have not tested rust converter using a powder coating. You do not typically use powder coats over primers, but is over bare metal. We do not know how effective the powder coating would be in adhering to the product. It may prematurely flake or blister.

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