The Problem
Metal cladding is used all over the world to cover warehouses, distribution centres, factories, facades and many other types of buildings. They are subjected to extreme conditions and stresses due to their constant exposure to ultraviolet radiation, pollution and aggressive weather.
Sheets expand and contract continuously under the influence of changing temperatures, At the same time they need to protect against corrosion and degradation from continuous exposure to the elements. Climates around the world are becoming more extreme with high UV and heavy rainfall.
The coating starts to change appearance after several years and sometimes very quickly depending on the location and orientation of the wall. The colour and gloss will fade or becomes chalky, rust sets in especially on cut edges and around bolts and fasteners. As the rust creeps the original coating will begin to peel or delaminate leaving the metal exposed to accelerated corrosion.
Most metal cladding is coil coated steel or galvanized steel produced on coil coating plants and supplied to specialist metal cladding and roof fabricators. They cut, fabricate and insulate sheets for delivery to site. The most common coatings applied at the coil coaters are plastisol, pvdf and polyester powder coating. Although some buildings will use galvanised steel which is then painted on site with acrylics or polyurethanes.
With plastisol and pvdf coatings it is advisable to check adhesion of the newly applied maintenance paint on a small test area before proceeding. Solvent based paints may attack these thermoplastic paints causing them to bubble and blister. Other paints may not adhere or flow out correctly on these coil coated sheets.
Metal cladding with extensive rusting in C4 aggressive Industrial and C5-M Coastal environments should follow special procedures here
The Solution
Metal Unicoat
Metal Unicoat is a quick, simple and economical solution for renovating metal cladding. It can be used for a simple makeover or for a more comprehensive renovation with a life expectancy in excess of 15 years.
It is a single product solution with anticorrosive properties, flexibility, good adhesion to different types of surfaces. It has excellent exterior durability, colour and gloss retention.
Metal Unicoat is a fast air drying ecological and sustainable paint. It has low odour and low emissions, it presents no fire hazard, is safe and suitable for application to occupied buildings with minimum disruption. It is available in an extensive range of RAL Classic and NCS colours in an eggshell finish.
Metal Unicoat is a unique primer finish, made in the West Midlands for free delivery throughout the UK.
Recommended quantity and thickness
The thickness to be applied will depend on the environment and the condition of the existing metalwork. Two coats are normally recommended to ensure total coverage with a total dry film thickness on 190 microns with a theoretical coverage of 5 square metres per litre.
Benefits & Performance
Metal Unicoat is a unique primer finish which can be applied direct to plastisol , pvdf and powder coated metal cladding sheets with a life expectancy in excess of 15 years. It is a cost-effective maintenance paint for metal cladding, easy to apply by roller or spray. For the owner or project manager it offers great benefits in terms of an economic solution for rebranding warehouses and factories without the need for abrasive blast cleaning. For the contractor it is a safe , easy to apply , fast drying single product solution which requires no additional primers or products.
For the project manager:
- .Economic solution for metal cladding
- No abrasive blast cleaning required.
- High performance and exterior durable system.
- 15 Year performance.
- Ecological and Sustainable paint.
- Low VOCs and Emissions. No fire risks.
- Low Odour, minimal disruption.
- Made in the West Midlands.
- Wide choice of RAL & NCS colours.
- Free Delivery no hidden costs.
For the applicator:
- Single Product Solution. No primers required.
- Suitable for repainting plastisol & pvdf.
- Quick drying, High Build and easy to apply.
- No isocyanates or Pot life issues.
- Low VOCs and Emissions. No fire risks.
- Made in the West Midlands.
- Fast and Free Delivery to site.
- Wide choice of colours.
- Available in small 5lt and large 20lt containers.
Preparation
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, ensure 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.
Metal Unicoat has no recoating window. Should the works be interrupted because of a sudden change in the weather, they can be continued later without any overcoating problems.
Surface preparation
The surface must be clean, dry, degreased and free of any contamination.
Eco Powerclean a powerful biodegradable alkaline concentrate composed of anti flash rust additives is recommended for cleaning and preparing surfaces before painting. When high pressure water blasting up to 4% Eco Powerclean can be added to clean water to improve degreasing and temporarily protect the surface from flash rusting. After application the surface should be left for 2 to 3 minutes for it to react with the metal. It will significantly improve the corrosion protection on exposed metal surfaces and reduce cleaning times. At 5% dilution usage is 100m2 per litre. Allow to dry before applying Metal Unicoat.
High pressure water blasting is recommended at a minimum of 180 bar (2600 psi) equipped with a rotating zero-degree angle nozzle. This method will remove surface contaminants, loosely adhering paint, corrosion salts and rust.
Ensure any existing coatings not removed by pressure washing have good adhesion and rough edges are feathered back to a firm edge. Never paint on top of a poor adhering coatings.
Cleaning by mechanical or power tools is advised when more detailed surface preparation needs to be done on objects within the cladding such as pipes, access ladders and bolts that could be heavily rusted.
Moss and mould can be removed with Eco Powerclean biodegradable solution.
Inspect and treat bolts
Inspect the bolts and fasteners, defects should be repaired or replaced with new ones. Apply a patch spot coat of Metal Unicoat 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, these are the weak points and quickly deteriorate due to corrosion creep if not treated correctly. Apply a spot coat of Metal Unicoat by brush. It will provide excellent edge protection.
Preparing the products
Products are supplied 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.
In hot weather conditions, you may dilute the coatings with clean water to slow its drying. But do not add more than 3% of water as this will diminish its anti-corrosion properties.
Metal Unicoat should be applied by airless spray to achieve the recommended film thickness in the minimum number of coats. If spraying is not possible, you can apply by brush or roller although more coats will be required to achieve the total recommended dry film thickness.
Specifications for airless spray application:
Metal Unicoat should be applied by brush on specific localised areas and with an airless spray gun on the main surface.
If spraying is not possible, it can be applied by roller. It will take longer, and you will need to apply more coats to achieve the minimum thickness required..
For airless spray use a pressure of at least 180 bar or 2600 psi and a gun opening between 0.013 and 0.015 inches. It can also be applied using the portable airless device Ultra Max from Graco. It’s a simple and effective method for small jobs or for touch ups on larger scale projects.
For application by roller, it is recommended to use 14 mm / ½ inch polyamide rollers or 3/8 inch nap rollers.
At the end of your project, clean your equipment with tap water.
System Application
Ensure the surface to be painted is free of oil grease and other contaminants. 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.
Measure the thickness of any remaining intact coating or galvanized steel for later comparison after applying the coating system. If you do not have this device, you can use a wet film comb gauge during the application.
Patch and spot prime any areas of exposed metal , cut edges, hand prepared bolts and accessories. After 4 hours apply a full coat of Metal Unicoat on the entire surface. Measure the wet film thickness during the application as this will help to calculate your dry film thickness on your final coat.
Allow the paint to dry for 4 hours at 15c before recoating. Depending on the ambient temperature this can be shorter or longer. Apply a full second coat of Metal Unicoat over the entire surface.
After 4 hours of drying at 20°C, the coating is dry and rain safe.
When working with a dry film measuring device, it’s time to control your total thickness. Subtract the thickness of the existing aged paint and galvanization to calculate the total applied dry film thickness of Metal Unicoat.
Metal Unicoat is available in an extensive range of RAL Classic and NCS colours in a satin finish. Free delivery throughout the UK in 5lt and 20lt containers.