How to prep for applying new non-skid paint depends primarily on the paint selected, and how you want the end result to look.
Basically, there are two types of non-skid paints:
- Paints that are applied with a textured roller to create a non-skid pattern (such as KiwiGrip)
- Paints that contain non-skid additives
Paints that use a textured roller can cover up small surface imperfections and usually require simple preparation that entails cleaning the surface by removing any contaminants such as dirt, dust, wax, grease, or oils, then sanding to remove any gloss. Metals need to be etched, as necessary, but usually no primer is needed.
Regular 1- and 2-part paints must be applied in thin coats to allow the paint to cure and perform as expected. This type of paint will take on the texture of the old substrate, whether it's smooth, or a molded non-skid. Some of these paints come with pre-mixed non-skid additive and a flattening agent to reduce the sheen, but you can also choose a topside paint and mix in additives to create a custom sheen and texture. Always check compatibility before adding any additives to the paint.
For 1-part, air dry paints such as Interlux Interdeck, TotalBoat TotalTread, or Pettit EZ Decks, the surface must be cleaned of any contaminants such as dirt, water, oil, grease, or wax, then sanded. It's not always necessary to completely remove previous molded non-skid texture. Priming is not always mandatory either, and each specific paint will list any recommended primers based on the substrate material and condition.
Generally, two-part activated paint systems such as AwlGrip, Quantum 99, and Interlux Perfection will require an epoxy primer to bond to. The cleaning and surface prep must be done to the highest standard because 2-part paints are repelled by contaminants, commonly leaving the dreaded 'fish eyes' (unsightly craters) in the paint. In many cases, it's easier to clean and prep by sanding off the old non-skid texture and starting with a smooth foundation for the new paint.