Dip coating is a process that is used to coat various types of metals, ceramics and plastics by dipping an object into a bath of the coating material, letting it sit and then removing it. The coating bath may be either heated, used cold or electrically charged. This is not a very efficient process as it is person dependant and is generally used for low-end applications that are not subject to high wear or in applications that do not require a consistent thickness of coating. However, dip coating is a good method of coating items that have irregular shapes.
Like other types of coating, dip coating is performed to give an object a layer of protection from things such as corrosion, heat, electrical interference, scratching and other abrasions, and thermal shock, etc. It can also be performed to give an item a decorative coating or fishing. The types of coatings that are used in dip coating are primarily plastics and paint.
The process of dip coating consists of: preparing the surface for treatment, preparing the bath with the coating substance until a uniform temperature or consistency is achieved, dipping the object into the bath, slowly withdrawing it and then air-drying it. Preparing the bath is very critical and care must be taken to make sure that the contents are not contaminated, the viscosity is uniform and there are no lumps of solidified powders inside the bath. Also, there is a tendency for air pockets to form when a component is dipped too rapidly into the bath. It is important to dip the component at a uniform speed in an eddy-free bath.
Any type of substance that can withstand heat of up to 200 degrees centigrade can be dip coated in plastic. Dip coatings are done on various types of materials such as steels, ceramics, plastics, aluminums, and glass and various components such as covers, castings, housings, propellers, and shafts, etc. Dip coating is a fairly quick process however it isn’t generally considered to be the best way to coat items. Masking grease is often used to protect surfaces that should not be coated.