What are the benefits of cleaning model components before painting?

Before painting a model it is useful to give the parts a clean using mild detergent. One of the main advantages to this is that inevitably the component parts have been handled prior to painting and as such the modeller will have left a residue of fingerprint grease on the model. It is more difficult for paint to adhere to the surface if this grease is not removed. The easiest way of doing this is to allow the required parts to soak in lukewarm water with a small amount of mild detergent, such as washing up liquid. After washing, the parts can either be allowed to naturally dry or alternately can be dried with a lint-free cloth to remove excess water droplets.

This process can be conducted at the outset before commencing assembly of the model. This works well if the parts are to be painted on the sprue prior to assembly. Alternatively, it may be advantageous to assemble parts first and then clean them immediately prior to painting, thus ensuring better paint adhesion and uniformity of the paint finish and parts are dust-free.