How to renovate rusted steel objects or structures without blasting

RD-Elastometal, “direct-to-rusty-metal” coating system designed to
• Adhere onto and seal weathered metallic surfaces,
• Protect against corrosion

RD-Monoguard, « next generation » anti-corrosion coating
• Superior anti-corrosion properties
• Semi gloss industrial finish

Restore rusty steel objects on video

The problem

Usually, the surface of weathered steel objects is not even everywhere. Some areas have lost their protective layer of paint, others are showing deep rust craters, other areas may still look nice or have hidden rust under the paint, etc… 

It is often a mix of different situations. Making only spot repairs is time consuming, not very aesthetic, and will keep you continuously busy all year round.

The solution

lRD-Eastometal & RD-Monoguard

Using two of our most innovative water-based protective coatings will solve most situations in an easy and cost effective way:

RD-Elastometal is a unique product that offers unequaled performance and longevity. It combines in a single product, high waterproofing properties with very high anti-corrosion properties. With more than 200% elasticity, RD-Elastometal can flex and bend on any kind of surface it is applied on.

RD-Monoguard combines all the properties of next-generation coatings: water-based, low VOC, fast drying, high anti-corrosion properties, single component, combined with a nice semi-gloss enamel type of finish. The thickness to apply will depend on the environment and kind of project, these figures are a perfect guideline to follow:

These two exceptional systems are also used on metal bridges in the marine environment such as the Oresund Bridge connecting Denmark to Sweden and one of the longest bridges in Europe!

The thickness of each paint to be applied will depend on the environment in which the object is located, the type of project and the expected longevity.

However, considering that it is the surface preparation and the labor to apply the paints that make up the majority of a renovation budget, we generally recommend going with the best performing combination.

Industrial and marine environment

1st layer: RD-Elastometal at a rate of 0.5 Kg / m²

2nd coat: RD-Monoguard at the rate of 0.2 L / m²

Benefits and expected performance of the system

The lifespan of the system is generally over 15 years! And a majority of projects can benefit from the RD Coatings warranty. See the "RD Coatings Warranty" page for details.

The main advantages of the system we offer are:

For the project manager/owner :

  • No blasting required, economical solution
  • High performance and durable system
  • Eco-friendly
  • Water based, safe, no fire hazards
  • Virtually odorless, can be used in occupied buildings without disturbing
  • Wide choice of colors
  • Limited downtime, possible to apply within 24 hours

For the applicator : 

  • Easy application
  • Almost no VOC
  • No isocyanates
  • High performance
  • Proven track record
  • No pot-life
  • One-component and quick-drying
  • No need for solvents nor thinners.

Getting ready

Weather

If the project is outdoor, avoid starting a job if it may rain within 3 hours after application. A minimum of 12°C / 54°F is recommended to have comfortable and safe working conditions. It also allows higher productivity.

Avoid working under direct heavy sunlight, especially in very warm regions where early-morning work or late evening are preferred.

Make sure there is no condensation on the surface before and during the application and the first hours of drying. If you are working indoor, make sure that the area is well ventilated.

Tip: RD-Elastometal has no recoating window. In other words, should the works be interrupted because of a sudden change in the weather, they can be continued later without any problem!

Surface preparation

The most popular and fastest way to achieve a good surface preparation is to high-pressure wash the surface at 300-350 bar or 4000-5000 psi of pressure with a zero-degree angle oscillating tip. This procedure will remove contaminants, poor adhering paint and -rust from the surface. Remaining paint or rust that resisted may remain as the adherence is still sufficient.

Hand- or power tool cleaning (with abrasive paper or steel brush) is also an option and is advised when more detailed surface preparation must be carried out. 

Make sure that the surface is free of moss, mildew, oils,  greases and chlorides (salts). Rinse using an alkaline solution if not already mixed to the high pressure washer. Think of using biodegradable solutions that can be easily found and are very effective. 

Verify if the existing coating is still adhering properly and there is no loose rust. Never paint on top of a poor adhering coating.

Inspect and treat bolts

Inspect the bolts and screws if any. Defects should be repaired or replaced with new ones. Apply a spot coat of RD-Elastometal by brush after inspection. This will help in the inspection process and provide added waterproofing and anti-corrosion protection in these critical areas.

Edges

Check edges, especially when sharp. They are the weakest parts and are quickly subject to corrosion if not treated correctly. Apply a spot coat of RD-Elastometal by brush. It will perfectly cover these edges and further protect them.

Soap

An additional step which may depend on the location and the extent of the pollution would be to use soap and water to degrease the surface and remove any oils, pollutants and grease. Observe the surroundings to see if any chimneys are emitting fumes as they can cause an accumulation of contaminants on the surface.

Preparing the product

Products are ready for use.

Mechanically stir the products for a few minutes before the application. Do not add any water to any of the products except when clearly specified.

Only if you are working in hot weather conditions, you may dilute the coatings with clean water to delay its drying. But do not add more than 3% of water in order not to diminish its anti-corrosion properties.

RD-Elastometal and RD-Monoguard are best to be applied by brush on specific areas and airless sprayer on the main areas. If spraying is not possible, you can also brush the coating. 

Equipment

Choose the type of brush according to the size of the objects to be painted.

Specifications for an airless application

RD-Metal Unicoat: output of 180 bars / 2600 psi and a tip size between 0.013 and 0.015 inches.

RD-Elastometal: minimum output of 180 bar or 2600 psi and a nozzle between 0.015 and 0.019 inches.

Both products can also be applied using the Graco Ultra Max portable airless device. It's a simple and effective method for small jobs or for touch-ups on larger scale projects.

Simply rinse the airless device with clean water when changing the product.

At the end of the job, simply clean your equipment with plain water or according to the equipment manufacturer's manual.

We do not recommend applying by roller as it is difficult to achieve the prescribed thicknesses. If you decide to do this, you will need to apply multiple coats to achieve the recommended thicknesses. We recommend using 14mm polyamide rollers or 3/8 inch nap rollers.

The application

Verify that the surface is dust-free with no contamination and no condensation.

If interrupted during the application we recommend that the areas to be coated be re-pressure washed or rinsed, usually if the surface has sat for more than 3 days without rain fall or located in a polluted environment.

When spraying RD-Elastometal, applicators are amazed to see that there is almost no overspray, which results in a better yield. The coating is also Dry Fall, paint dust can easily be removed once it is dry.

Using an airless, the prescribed thickness can easily be achieved in one single pass and beginners who may sometimes spray too thick will notice that there is no sagging up to 1mm and more!

If you use a brush, you might have to pass 2 times to reach the indicated thickness. Eventually finish details such as small metallic objects, corners and edges with a brush.

The thickness is important and needs to be in line with our recommendations as it will be your guarantee for the long-term performance of RD-Elastometal. Think of measuring the wet film thickness during the application as this will help you to figure out your future dry film thickness.

Let the paint dry for +/- 6 hours. Depending on the weather and the thickness you applied, this can be shorter or longer.

Apply the second layer of RD-Monoguard on the entire surface by brush or using an airless.

RD-Monoguard is more an enamel type of coating, do not apply thick coats in a single pass to avoid sagging and favor a second pass several minutes later to build up the thickness.

230 µm wet 9 mils is usually the maximum achievable thickness in 2 or 3 passes.

Eventually finish details such as small metallic objects, corners and edges with a brush. Think of measuring the wet film thickness during the application as this will help you to figure out your future dry film thickness. 

RD-Monoguard dries fast, usually within 1 to 3 hours depending on the temperature.

The products you need