If the existing coating is intact there are some important rules which should be followed:
Where the composition or structure of a coating is unknown it is recommended that the coating be re-constructed from scratch. The chances of saving time and money by experimenting are very slim, and the results usually unsatisfactory.
Only apply a suitable system to an existing coat.
Rule of thumb:
Do not apply two-component products to one-component underlayers unless this is specifically endorsed by the manufacturer.
Selfpolishing or Teflon (PTFE) based antifouling coatings can only be re-coated with the same material.
