Painting Aluminium and metal surfaces, in general, require a slightly different approach compared to wood and timber.
Painting aluminium and metal surfaces requires a slightly different approach compared to painting on wood and timber. Aluminium requires elaborate surface preparation. Aluminium does not rust like steel and iron. Rather it naturally oxides forming an invisible thin film of aluminium oxide. So that paint can adhere to the surface, this oxidation layer must come off. To paint aluminium there are surface preparation steps to be followed thoroughly. Surface preparation commences with cleaning the surface of dust, dirt, oil, debris, grease and anything else that bids itself on open surfaces. Sanding of the surface gives it a texture where primer and paint can adhere to. After sanding is complete, apply an etching primer before undertaking the paint job. Surface preparation is the most critical step when painting aluminium. Well prepared surfaces ensure optimal adhesion of paint to the metal surface. Good adhesion prevents premature chipping and unwanted peeling of paint. With minimal peeling, the aluminium walls, furnishings or furniture will have longer life spans saving you a replacement and repainting money. When surface preparation thorough, you can attain a smoother finish.
Aluminium is a metal that is difficult to paint. However, advances in paint technology have made painting aluminium easier, with good paint job results too. Nowadays, it is not uncommon to find products labelled Aluminium paint. Practice however dictates that you still have to clean sand and apply primer before painting Aluminium. The application of primers is a critical step before painting. The active ingredient in an etching primer will directly affect the paint applied on the aluminium surface. Experts recommend that when an oil based primer is used, an oil based paint be used too. Similarly, where latex primers are used, latex paints be used to paint. Take note of the fact that latex-based products have ammonia as an ingredient that can react with aluminium. The paint applied also depends on the condition where the aluminium item or furnishing is used. If the item is for outdoor use, matt paints are ideal because they are less reflective. Sanding scratches, sandpaper lines and dents are less visible. This paint also withstands the excesses of hot conditions. Gloss paints are expressive and reveal the fine visible details. They are therefore suited for indoors and cooler weather conditions. If you are not a DIY person, seek professional services.
Surface preparation is the most important part of painting aluminium. By its nature aluminium requires more preparation than other metals. This detailed preparation does not allow you to paint directly onto the aluminium though. After cleaning and sanding thoroughly, the surface needs priming. With aluminium, do not make the mistake of using regular metal paint primer. Use the self etching primer. The self etching primer is available at the auto accessories shop or a home improvement store near you. Search online for a store near you or order online. Read the etching primer manufacturer’s manual or instructions comprehensively. Before spraying the primer, as a rule of the thumb, shake the can vigorously for at least 45-60 seconds. Apply the primer by holding the primer can 8 inches (20cm) away from the surface. Evenly apply a light coating. Whether you choose side-to-side or up and down spray motion, ensure that the primer coat is uniform. Allow 5-minute intervals between coats or as indicated on the product for curing and drying. Apply 3-4 layers of light coating adhering to waiting times. If necessary, sand the surfaces in between primer applications using fine-grit sandpaper. Only after priming can you directly paint onto the aluminium.
Preparing aluminium surfaces for painting requires cleaning, sanding and priming. Firstly, protect yourself using personal protection equipment. It is recommended to have or purchase gloves, goggles and dust masks.
Cleaning. Aluminium surfaces will come in many types, shapes and forms. These can be exterior walls, doors and window sections, and aluminium furnishings or furniture. If the surface allows, apply water to wash away dirt, dust, debris, grease, soot and oil. For oily and greasy surfaces, add degreaser chemicals to the water. To clean and wipe the surfaces, use rags or cloths. Rinse surfaces well. Wait to air dry completely.
Sanding. Sanding involves smoothening the surface using rubbing materials like sandpaper, steel wire or brushes. Start with coarse grit sandpaper of the 80-100 grade. Follow on with medium coarse grit paper of the 200-300 range. To attain a smooth finish, use super fine-grit sandpaper like the 400 grade. Use clean dry rags to dust off the surface thoroughly.
Apply primer. After sanding, apply primer as discussed in the previous section. After priming, the surface is ready for painting.
Painting aluminium can be done by use of a brush, rollers or spray painting techniques. Using a brush is cheap, easy to use but is time-consuming. A roller is faster than brushes. Use rollers that are the same size or smaller than surfaces to be painted. Spray painting is fast, especially for large aluminium surfaces. Cover areas that you do not want to paint before spray painting. Use masking tape or an ideal material. Set aside a place where you will do the spraying. It should be away from direct sunlight and wind. Check online for tips to create a DIY spray painting space. Paint and primer chemicals expel fumes that can be harmful. Wear protective gear and work in well-aerated places. Spray painting colours are available for any project you can think of. Just like the application of primer, spray paint will require several coats. Spray, wait for curing and drying. Apply as many coats as desired but always follow product guidelines. Applying a coat of enamel protects the paint job from fading, chipping and getting scratches. Apply 2 coats of enamel sealer. Allow recommended time for drying and curing. Just like paint and primer, follow the instructions given by the manufacturer of your enamel sealer. You can call, contact or engage a professional paint job service provider if you need one.