What is the best paint to use on aluminum siding? In this guide, we will see under what conditions and to what extent you will need to paint aluminum. Furthermore, we will also analyze suitable painting techniques and paints.
What Is the Best Paint To Use on Aluminum Siding?
Painting aluminum, as in many other cases, has a dual purpose. The reasons for painting aluminum include:
Protection. Aluminum and some of its alloys are always susceptible to corrosion. Therefore, with the passage of time, this metal will experience degradation.
Painting aluminum provides it with an excellent protection from this electrochemical attack. Remember you use two treatments together, in the sense that you carry out painting on anodized aluminum.
Decorative. An aluminum frame or door that you protect with an anodizing treatment does not always match the colors of the walls or furniture. In such situations, it is necessary to paint it with the appropriate finish and color.
This will enable you to standardize the furnishing of the rooms. And in these cases, therefore, the painting has an aesthetic function that combines with the protective function.
Aluminum and its alloys
Aluminum is a metal with the following characteristics:
- Ductile (it deforms plastically)
- Lightweight
- It’s resistant to oxidation (reaction with oxygen), and consequently to corrosion (slow chemical process of consumption)
Because of these characteristics and its abundance in nature, manufacturers use aluminum in industrial processing. In the building industry, its primary use is in the alloys we use for the construction of windows and doors.
Keep in mind that metallic aluminum is very reactive. In order to protect it and increase its durability, it undergoes an anodizing treatment.
This is an electro-chemical process by which a thin film of oxide is deposited on the surface of the aluminum profile. It protects the metal from deterioration, and can serve as a useful base for subsequent painting.
Aluminum alloys are also known as light alloys due to their low specific weight. Manufacturers obtain them by combining aluminum in various percentages with various metals.
They include zinc, silicon, magnesium, and manganese. Manufacturers classify aluminum alloys according to their use in:
- Foundry alloys
- Alloys for plastic processing
Of particular importance for the building industry are the alloys belonging to the field of plastic processing. They are known as group 6000 or more commonly with the trade name Anticorodal.
These alloys are a large group of aluminum alloys with magnesium, silicon, and manganese. They are very resistant to corrosion. Manufacturers use them to build frames, windows, and doors.
What Is the Best Paint To Use on Aluminum Siding?
Painting aluminum well is not easy. However, the problem is not the preparation. It is the difficult adhesion of the film-forming resin that the paint contains on the surface.
These problems arise from the characteristics of the aluminum itself. Therefore, you should make a careful choice of the paints to use. Moreover, you should ensure a careful preparation of the surface on which you will paint.
What Is the Best Paint To Use on Aluminum Siding – The Most Suitable Ones Are:
Two-Component Epoxy Primer
A primer is a varnish that you apply on the bare metal. It provides protection and at the same time constitutes the primer for the next coat of varnish. In the case of aluminum, epoxy resin-based paints are the best option. They offer their tenacious adhesion, even to not very porous surfaces.
These paints are two-component and organic solvent based. The hardening, which is chemical, takes place through the action of a catalyst that is added only at the moment of starting the processing.
In the case of paints in spray cans, the hardener is contained in a capsule inside. When you shake the can vigorously, the capsule breaks and the two components are mixed.
Two-Component Polyurethane Enamel
It is an enamel that has a strong adhesion power to the surface and uses polyurethane resins as a binder that have a high protective power. In addition, they have excellent resistant to the action of ultraviolet rays.
All these properties make it particularly suitable for painting aluminum outdoors (it does not yellow). On the other hand, it has an unexceptional aesthetic finish.
Two-Component Polyurethane Transparent
This has the same characteristics as enamel, but being pigment-free, it is transparent. A final coat on the enamel increases the protective capacity of the dry film and increases its gloss.
Two-component acrylic paint. We use it as an alternative to polyurethane enamels when you want to obtain brighter and more vivid colors. Therefore, the aesthetic appearance in some way prevails over the protective factors.
We use it to paint to paint aluminum indoors, even if it provides good results outdoors.
What Is the Best Paint To Use on Aluminum Siding and Painting Steps?
Step 1: Choose your Paint and Painting Tool
We recommend that you use quality aluminum siding paints such as Sherwin Williams or Benjamin Moore.
Once the surface is clean and dry, you can proceed with the application of the paint. You must apply the paint with an airless spray gun.
Alternatively, you can use spray cans that are ready and easier to use. That is because they do not require dilution of the paint to bring it to the right viscosity.
Step 2: Apply the Primer
Start by giving a coat of epoxy primer, taking care to completely cover the outer surface of the product without interruption.
Then, let it dry (the time is indicated on the paint package), and give a second coat. The paint, as mentioned above, must be mixed well by joining the two components and brought to the right viscosity.
That is by diluting it with a solvent according to the instructions given by the manufacturer in the technical data sheet.
Tip: Paint Aluminum Siding When the Weather is Calm
For the best outcome, carry out painting operations in dust-free environments. Place the product on trestles for convenience during painting.
Step 3: Paint the Aluminum Siding
Once the primer dries, after about 24 hours, apply the the first coat of epoxy enamel . When the enamel is also dry, give a second coat.
Step 4: Seal the Paint with a Clear Coat
Finally, you can seal it all with a careful coat of clearcoat. If you want an aesthetically impeccable finish in terms of both color and smoothness, you can use a two-component acrylic varnish instead of epoxy enamel.
I do not quite understand the laborious techniques explained here with two part paints. I painted my aluminum siding, installed in probably the 1960’s, with the highest solids latex paint that I could find in the early 1990’s. The siding was beginning to show that typical bluish/gray sheen as the paint chalks and gets thin. I believe that I paid somewhere around $60 for a gallon. The surfaces were all prepped using scotch pads with multiple rinses of water. Here it is, 30 years later on both the south and north sides of the home and, save for the usual road dirt, the paint job has held up far beyond my expectations. Not a single peel or crack. Am I missing something?
Hello Mike,
You aren’t missing anything really.
The two-component paints are just alternatives to a quality latex paint.
Just like latex, their elasticity matches the expansion of the aluminum surface. That is critical in the longevity of the bonding between the aluminum surface, primer, and paint.
The steps can be as simple as these:
1. Choose a quality aluminum paint and painting brush/roller/sprayer.
2. Prep the aluminum siding
3. Paint the Aluminum siding
Thank you.