Recently I had the outside of my home painted. The contractor wrote a good contract, but I failed to realize that some things were not in it. It reminds me of the car dealer who offered a good price on a new car but failed to mention that it did not include tires. My contractor failed to specify that lattice under a porch was included. So the painters did not paint it. To his credit, he did instruct them to paint it when I brought it to his attention. If I had the job to do over again I would look for an individual who came with referrals from happy customers rather than a franchise owner..
Back to the article. You can add water to all latex based paints / thinner to oil based paint. The tinting base has absolutely nothing to do with it. Say you are working outside and throughout the day you have to add a little water to keep the same consistency. If somebody really tried to add 20% to 50% water they no longer would be painting they'd be performing a whitewash or pickle finish.
If less than half the old paint is left, however, it may be worth stripping it all off. Guertin gets rid of stubborn remnants using shrouded grinders (like the PaintShaver), infrared paint strippers (such as the Speedheater), or chemical strippers (like Multi-Strip), then smooths the wood with a course or two of sanding. When siding (or bank accounts) can't take the shock of a total strip job, Rich O'Neil, of Masterwork Painting in Bedford, Massachusetts, has successfully hidden rough, well-adhered paint under Peel Bond, a thick primer.
O'Neil patches shallow holes and divots with Ready Patch because it dries fast, sands smooth, and stays flexible. Deep cracks and rotten spots are best repaired with two-step epoxies, such as those made by Advanced Repair Technology. (For a step-by-step instructions, see Repairing Rot with Epoxy.) The days of using polyester auto-body fillers on wood are over. "They cure too hard," says Portland, Oregon–based painting contractor Kathleen George. "They look good at first, but then they peel away."