In most cases for new anodized aluminum a light sanding of the surface and acetone wipe will suffice. The acid may be chromic sulfuric or phosphoric.
Look to a good chemical company to provide you with a fluoride bearing treatment and a reactive non chrome final rinse.
Powder coating over aluminum. Unlike liquid paint powder coating doesn t require a solvent. What you need to consider before powder coating over an existing coating to be able to apply a powder coating over an existing coating the underlying coating has to be able to tolerate high temperatures typically powder coatings are cured at 250 400 degrees fahrenheit and so the underlying coating and part itself must be able to tolerate a high temperature so that the powder can be cured you are looking to completely recoat the product due to the way powder coating works you are not. Then get clean rinse water and you re all set.
Aluminum must be chemically treated prior to powder coating to get any kind of outdoor performance at all. Powder coating is the process of applying a decorative and protective finish on the aluminum profile or any other metal through an electrostatically charged powder which is sprayed on the aluminum. How can we get better adhesion and corrosion performance of powder over aluminum.
Chromic acid offers superior corrosion resistance but also more environmental challenges. The pre treatment process involves removing dust grease and any other foreign particles. Resins are often the weak link in an organic coating system.
The surface treatment should be carried out to increase the corrosion resistance and abrasion resistance of aluminium profiles. Yes you can powder coat over anodized aluminum. This type of questions has been a common one for me and others who offer advice on powder coating.
With aluminum the pretreatment is of utmost importance. That way the technician can ensure good adhesion and the powder coat won t flake. The performance of an organic coating paints or powders depends on the pretreatment resin and pigmentation.
Anodizing uses an acid to create an anodic film on the part. This is why organic coatings for aluminum should be factory applied. So it s very important that the surface of every extrusion is properly pre treated.
Chromic acid and phosphoric acid anodizing are more commonly used for aluminum that will subsequently be coated with an organic coating. However older anodized aluminum will most likely need abrasive blasting. You can then powder coat to color put in the oven for curing then put in service.
It is hard to give a simple answer on the best way to treat aluminum but i will offer you good better and best approaches. One of the most durable protective coatings for steel is provided by applying a polyester powder coating over hot dip galvanized steel to provide a high grade. Anodizing is done in different batches hence there are chances of color variation on the substrate.
2 apply powder to. 1 pre treat the aluminum surface. Powder coating over galvanizing presents it s own set of problems to the powder coater but nothing we can t overcome easily with a little knowledge on how to do it correctly.
Powder coating vs pvdf coating on aluminium surface the production process of aluminium profiles mainly includes three processes. Casting extrusion and colouring. Powder coating is the process of spraying electrostatically charged paint in powder form onto your extrusions.