Reward for lost Kraken!
Join Date: Apr 2006
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Probably only by taking a ship off and sending it to a paint company for inspection. If the deck was painted "properly" then everything was removed, rather than being masked. If you can see any signs of masking around the ports or hatch trim, etc., then you know it was painted.
Ask the maker of your new paint (excuse me, they call it "coatings" now) how you can test the existing deck, or if they will examine a chip for you. (Remove a fitting and take the chip from under it.) Or they may say it makes no difference, as long as you can apply a certain solvent to the existing deck without anything lifting from it. That's one of the main concerns, solvent lifting.