Cabot's Aquadeck Merbau 4LCabots Aquadeck lasts twice as long as other oil based decking oils, protecting your timber while enhancing your timbers natural look. You can use Aquadeck over any existing coating if the existing coating is at least 30 days old and in good condition. If the existing coating has peeled, flaked or deteriorated unevenly, we recommend that you completely remove the existing coating with a coatings stripper or by sanding back to bare timber to achieve