Many people love the simplicity and forgiving nature of wood finish products such as Sikkens Cetol® because it's easy to clean with boat soap and a sponge, and easy to maintain. Not to mention, unlike varnishes, the Cetol instructions recommend NOT sanding between coats, if at all possible (up to 2 weeks after applying the last coat).
Probably the most important thing for Cetol's longevity is to give it proper maintenance. It's extremely important to perform yearly maintenance coats. Always address areas that are not in good condition as punctually as possible. The longer that scratched, peeling, or stained areas sit, the more work it will take to return them to the desired condition because the wood underneath may be exposed, creating a stain, mildew, or general degradation.
Yearly maintenance coats are just as important because UV rays cause the finish to break down, making it more prone to scratches, peeling, or bubbling up. This UV damage can also give the Cetol a more cloudy appearance
The first step to prepping the surface is to clean the old Cetol surface so it's free of any waxes or contaminants. Then sand the surface lightly with 220- or 320-grit sandpaper, taking care not to remove much material, and to remove any sanding residue. Once the lightly sanded surface is clean and dry, apply any maintenance coats of Cetol, as directed.