How to repaint heavily rusted metal claddings or located in an aggressive industrial or marine environment?

RD Coatings offers high-performance coatings that provide long-term protection for metal cladding and steel sheets against corrosion and rust.
Even rusty metal cladding in industrial and commercial buildings can be given a new lease of life with an attractive finish.

The products you need

The problem

The coating layer of metal claddings protecting the walls are subject to bad weather and different climates that can be very aggressive at the seaside or in very polluted industrial areas. The rays of the sun, the rain, the wind carrying chlorides, atmospheric pollution coming sometimes directly from the neighboring factory, attack these surfaces on a daily basis.

The original coating deteriorates, begins to peel off or even disappears completely, leaving the metal of the cladding bare and exposed, and without protection. Rust begins to set in...

The harsher the environment and the more exposed the surface is, the faster rust will appear and will quickly spread over the entire surface. There are ways to stop these degradations and fix them in the long term.

RD Coatings offers eco-responsible and easy-to-apply solutions that will effectively and durably protect metal claddings and steel sheets!

The solution

RD-Elastometal & RD-Metal Unicoat

To stop the action of rust and renovate the metal cladding, it is necessary to use a combination of RD-Elastometal as a first coat and RD-Metal Unicoat as a finish. 

RD-Elastometal will provide excellent corrosion protection. It adheres perfectly to metal, galvanized (> 1 year old) or aluminium surfaces. Thanks to its permanent elasticity, it will follow the expansion and retraction movements resulting from permanent changes in surface temperature.

RD-Metal Unicoat is applied as a finish. Available in a wide range of colours, it gives a neat aesthetical finish in accordance with the company's colours, for example.

Recommended quantity and thickness

RD-Elastometal: 0.4 kg / m² for 175 µ sec - 130 p² / gallon for 14 mils sec.
RD-Metal Unicoat: 0.20 L / m² for 95 µ sec - 200 p² / gallon for 3.8 mils sec.

The total thickness obtained will be +/- 270 µ / 10.8 mils sec.

These products have good anticorrosive properties, are UV and weather resistant. They are one-component and water-based and therefore do not present any danger or fire risk. They are also suitable for application on occupied buildings and will not affect occupants.

Benefits of the system

This system offers multiple advantages for the contractor and the applicator:

- one-component and ready-to-use
- low VOC (Volatile Organic Compounds) levels
- quick and easy to use solution
- fast drying time and reduced downtime
- extensively tested worldwide
- wide range of colours and very good durability

Our water-based products prevent:

- bringing hazardous products to the site while eliminating the risk of fire or explosion
- nuisances in the vicinity with annoying odours during and after application
- emissions of harmful substances
- losses during and after application

Getting ready

Weather

When working outdoors, avoid starting a job if rain is forecast within 4 hours of application. A minimum of 12°C / 54°F is recommended for comfortable working conditions with higher productivity. Avoid working in direct sunlight, especially in very hot areas, where early morning or late evening work is preferred. Ensure that there is no condensation on the surface before and during application, and during the first hours of drying. In the case of facades, it is sometimes possible to work according to the rotation of the sun, preferring the shaded area in summer and in very hot weather and the sunny area in cooler weather.

Ensure that there is no condensation on the surface before and during application, as well as during the first few hours of drying.

Good to know

RD-Elastometal and RD-Metal Unicoat have no overlap window. This means that if work is interrupted (e.g. due to a sudden weather change), it can be resumed later without any problems, after rinsing the surface with a high-pressure cleaner at a more or less moderate pressure, depending on the degree of soiling.

Surface preparation

The surface must always be clean, dry, degreased and free from any contaminant.

The most convenient and quickest way to do this is to clean the surface using a high pressure washer powered at minimum 275 bar / 4000 psi equipped with a rotating zero degree angle nozzle. This method will remove non-adhering rust and contaminants, as well as existing paint showing lack of adhesion.

If the existing paint resists to the cleaning, it means it has sufficient adhesion and can stay in place.

Cleaning by hand or with a metal brush or power tool is also an option and is advised when more detailed surface preparation needs to be done on objects near or on claddings, such as access ladders, ventilation, doors, bolts, etc. that would be rusted.

Moss and mold can be removed with suitable cleaners. Consider using biodegradable solutions that are easy to find and very effective.

 

Rust

In case of rust, it is imperative to remove the non-adherent elements and to obtain a surface corresponding to the ST2 - ISO 8501-1 / SSPC SP2 or SP3 standard.

Inspect and treat bolts

It is important to inspect the condition of the bolts securing the metal panels to each other and to the wall structure. Defective fasteners and bolts must be repaired or replaced.

Trick

Brush a spot coat of RD-Elastometal over each fastener after inspection. This will not only help visualize the progress of the inspection, but also add a protective first layer to those weak spots.

Edges and ridges

Also check the edges and ridges. These are places easily subject to corrosion. Remove all contaminants and apply RD-Elastometal by brush. You will notice that it covers the edges perfectly and will protect them even more.

 

Equipment

It is preferable to apply RD-Metal Unicoat and RD-Elastometal with a brush on specific areas and with an airless on main areas. If spraying is not possible, you can also apply the coating by brush. Choose the type of brush according to the size of the objects to be painted.

Specifications for an airless application

RD-Elastometal: minimum output of 180 bar or 2600 psi and a nozzle between 0.015 and 0.019 inches.
RD-Metal Unicoat: 180 bar / 2600 psi outlet and nozzle between 0.013 and 0.015 inches.

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 and multiple coats must be applied to achieve them. We recommend using 14mm polyamide rollers or 3/8 inch nap rollers.

The application

The products are ready to use. Stir them mechanically for a few minutes before application. RD-Elastometal has a fairly high viscosity, which is normal. Do not add water except when clearly specified.

Check before each application that the surface is free of dust, contamination or condensation. If preparation or application has been interrupted for more than 3 days without rain or if it is located in a polluted environment, we recommend that the areas to be coated be washed or rinsed with a high pressure cleaner again.

A dry film thickness gauge can be used to measure the thickness of the remaining coating or galvanisation and to determine afterwards the thickness of the applied paint. It is also possible to use a wet film gauge during application which we can supply.

Apply the first coat of RD-Elastometal over the entire surface.

The recommanded thickness is important and should be in line with our recommendations. It will be your guarantee for the long term performance of the system.

Allow the paint to dry for 6 hours before recoating with RD-Metal Unicoat. Depending on the weather, it can be shorter or longer.

Apply RD-Metal Unicoat over the entire surface. After 4 hours of drying at 20°C / 68°F, the coating is dry and resistant to rain.