As you can see in the picture,saltwater is turning areas of this deck and rails a black color.I was thinking about putting a bed liner rhino type cover on it.Would I need to treat it with a chemical to get it to adhere to the aluminum or put it straight on it???

Not sure.. I would think you could spray it straight on.. at most maybe scuff it up with some fine grit sand paper.. might check with a local shop that does bed liners to be sure.

I know thats the way to do a regular truck bed,just wasnt to sure about the Aluminum.Guess we will just give it a try and see what happens.