Preparing a deck to accept new stain isn’t difficult because the liquid strippers and cleaners do most of the work. However, it’s the one step where some DIYers take shortcuts and that’s a huge mistake. If you fail to strip off all the old water/acrylic base finish, the new finish will fail early. The same applies to taking shortcuts with the cleaning/neutralizing step. Wood cleaner neutralizes the stripper, removes dirt, brightens the wood and opens the wood’s pores so it can more readily absorb the new stain. Prepping the deck properly is critical to achieving an even application that penetrates, adheres well, repels water, shields against sun damage and lasts the longest. Here’s how to prepare your deck for staining.
Strip Off a Water/Acrylic Finish
Protect plants around your deck with a fabric drop cloth or light colored tarp (not clear poly sheeting—the “greenhouse-effect” will fry your plants especially if the sun is out). Then wet down the siding near the deck using your garden hose. Wet surfaces are less likely to be damaged by splashes from the stripping products. Clean off all loose deck debris with a push broom or leaf blower.
Make sure you are wearing proper protective clothing including eye protection and acid resistant gloves. Shake the and pour it into a paint tray. Working in small sections, roll on a thick coating using a ½-in or ¾-in. nap roller and an extension pole. Wash off any stripper that may have splashed onto areas not intended for stripping. Let the stripper settle into the wood for 15-45mins. If the stripper starts to dry during this period, re-wet it with water. Then scrub the boards with a stiff bristle broom. If you have thick layers of stain, you’ll speed up the job by scraping off the residue with a floor scraper. If that’s the case, you’ll likely have to reapply more stripper for the scrubbing step. Rinse off the stripper and loosened stain using a stiff stream from a garden hose nozzle or a pressure washer set to the lowest setting. A pressure washer makes the job much easier. If you only have a garden hose, you’ll have to do some more scrubbing as you rinse.
Let the deck dry and areas that need additional treatment will be obvious. Repeat the stripping/scrubbing routine on those spots.
If, after several rounds of stripping you still have patches of stain, sand them with a random orbital sander. Now you’re ready to clean and neutralize the deck. Or, hire a professional floor sanding company to sand the entire deck.
Clean and Neutralize the Deck
Clean the deck using Mix a 50/50 solution of water and cleaner for reasonably clean wood, or use the cleaner at full strength for extremely weathered boards. Experiment with a small area to determine which is best. Wet the wood with your garden hose and apply a liberal coating of the cleaner using a pump sprayer. Let the cleaner sit for 10 to 15-min. before scrubbing with a stiff bristle broom. Then rinse the entire deck and let it dry.
Lightly sand the deck with a drywall sanding pad and 150-grit sanding screen. That’ll knock down any raised wood fibers and give much smoother finish. Blow off the sanding dust with a leaf blower and you’re ready to stain!