Aluminum Painting: Technology and Tips

Painting of aluminum and other non-ferrous metals is associated with some difficulties associated with rapid oxidation. Under the influence of oxygen, an oxide film is formed on the material, which minimizes the adhesion of any coating, including varnishes and primers. Because of this self-coloring is often short-lived and does not look the best.

Anodizing

Despite the modern range of primers, they do not give the desired effect, and the paint layer peels off at the slightest impact.

Improve the adhesion of paint and aluminum surfaces by anodizing metal. This procedure consists of electrochemical or chemical treatment, due to which the intensity of oxidation decreases. Virtually all products made of non-ferrous metals, painted in production conditions, pass through anodizing on special devices.

Materials and Tools

At home, you can also carry out this procedure or use special primers. Powder painting of aluminum with anodizing takes more time and contributes to increased costs, but the result is worth the effort. Preliminary need to prepare tools and materials, without which it is impossible to achieve a durable and high-quality coating:

• Sprayer, roller or brush;
• Sandpaper with fine granularity (necessary for matting the aluminum surface);
• A container for placing the part to be processed;
• Vinegar for dilution of paint and varnish composition;
• aniline dye;
• Means for degreasing;
• Ingredients for electrolytic composition (water, salt, baking soda).

Course of work

Aluminum painting begins with the connection of the ingredients for the electrolytic composition and the preparation of the solution. The amount of water should be sufficient to completely immerse the aluminum element. The resulting liquid is poured into two identical containers. In one of them soda is poured in the ratio of 1 to 5 (soda and water, respectively), in the other is added salt in the same amount. After that, the liquid is mixed until the additives are completely dissolved. The next step is the percolation and compounding of the composition of the two vessels. The solution should settle, at this time you can polish the metal surface. Fat and dirt are removed with a cloth soaked in acetone.

Further, individual elements are rinsed under running water and placed in a container with a solution. Preliminary it is necessary to put on rubber gloves for safety.

The negative terminal is connected to the tank with the immersed parts, plus - directly to the elements themselves. Anodization continues for 2-3 hours before the appearance of a bluish-gray hue.

Further, aluminum can be painted at home. The coloring composition consists of 1 liter of liquid, 20 grams of aniline paint and 2 ml of vinegar. The solution must be heated to 80 degrees with constant stirring. Products that have passed through the anodizing procedure are placed in a container with a coloring composition for 15-20 minutes.

Aluminum painting: technology

Anodizing aluminum is not a mandatory item. If necessary, you can do without this procedure, using a primer that allows you to increase the adhesion of paint and metal. Painting of aluminum with a primer is performed using the following materials and tools:

• Kerosene, acetone and any other means for degreasing;
• Special paint for metal;
• Primer on alkyd basis;
• sandpaper;
• Roller or brush.

Aluminum painting at home begins with surface treatment with sandpaper to increase adhesion to the primer. The best option is an abrasive with medium-sized coating. After careful grinding, the products are treated with acetone using a cloth that does not leave pile. To protect the skin of hands, you should use rubber gloves.

Then a primer is applied to the surface. At the same time, it needs to be distributed quickly and immediately after processing, since the durability and reliability of the coating depend on this. It is recommended that the primer be prepared before grinding the surface. Flows and irregularities that occur after application of soil can be removed using grinding paper.

Painting of aluminum is made at least in two layers, and before applying each of them the previous layer should completely dry.

Powder Paints

Powder composition is also used for the coloring of aluminum. It provides a reliable, durable coating in the form of a monolithic layer, not only decorating the material, but also reducing the likelihood of corrosion.

The first stage is surface preparation. In industrial conditions, salt and impurities are removed from parts, then rinsed with water. In addition to standard degreasing, aluminum painting with powder paint involves phosphating, which increases the adhesion of metal and paint.

The elements are then dried under high temperature and cooled. Of particular importance is the polymerization process, which consists in applying a special polymer layer under air pressure. Work is carried out using an electrostatic atomizer, which forms the thinnest layer on the surface.

After applying the paint, the aluminum products are placed in a special oven and are heated to 200 degrees for 10-15 minutes. Curing of the layer occurs during the cooling of the metal.

The use of specialized tools and furnaces complicates the process of painting with powder formulations at home, which is why it is often replaced with anodizing.

Application of powder paint is possible on any aluminum parts. This technique was most widely used to cover parts that are intended for use at temperatures up to 220 degrees.

Staining with a balloon

Before using this technology, standard preparation of the material is used, for example, as in anodizing. Among the features worth noting is the need to maintain a sufficient distance between the surface and the can, and also applying a large number of layers. Since the application of the previous layer should pass at least 20 minutes, only then can be covered with the next layer of paint. The number of layers varies from the quality of the paint and the use of the part. On average, it can vary within 3-15 applications.

Features

It is important not to forget about the periodic shaking of the balloon, it will help to avoid streaks and divorces. In some cases, the nozzle may be clogged. To clean it, it is necessary to turn the balloon and spray the composition until the transparent composition appears.

After the completion of painting, if there are residues, they must be removed to a place protected from exposure to sunlight. The tools used are cleaned with a solvent. Painting for aluminum is made in the same way, regardless of the material used for work.

Types of paints

The final result is influenced not only by compliance with all the subtleties of works, but also the quality and characteristics of the chosen paint. Several variants took the most widespread approach:

• Acrylic composition is resistant to damage, moisture and sharp temperature changes. Apply the paint over the primer layer.
• Epoxy is made on the basis of special resins, due to which it has such characteristics as durability and strength.
• Aniline was originally created for the textile industry. This paint is optimally suited for aluminum products that have undergone anodization. But it is not without drawbacks, in particular, the composition is characterized by low resistance to moisture and sunlight.