How much preparation is necessary before painting my topside?

The most critical aspect of any painting job is preparation. Poor surface preparation will always show through the final coat; this will reduce the effectiveness of the coating system and can potentially lead to the premature failure and separation of the coating from the substrate. As a guide, you should be aware that you will need to spend up to 80% of your time on preparation and priming, in order to achieve a first class finish of which you can be proud.