Old, weathered stain or paint can wear unevenly or become dull and lifeless, so it's tempting to just cover them with more. But the new coat won't adhere or wear well if it's not applied to a clean, smooth surface. Instead of covering the old finish, remove it with a chemical stripper or heat gun.
Work in a well-ventilated area such as the patio itself or your open garage. Make sure your work area is dry and dust-free. Use masking tape to secure a large drop cloth or tarp to the ground or floor to prevent potential stains from spill and splatter.
You can remove any flaking, loose paint or varnish by first scraping it off with a paint scraper. Using a medium-sized paintbrush, apply Woodsman® Premium Wood Stripper evenly over the surface in a thick coating, with a single pass of the brush. You don't have to brush it out the same way you would a coat of paint. Let it soak 20 to 30 minutes then remove the old finish using a plastic scraper or a smooth, round-edged putty knife. Wait until the finish has bubbled up before trying to remove it. The surface may be soft so be careful not to damage it with the scraper. Allow the bench wood to dry completely.
Always follow manufacturer's instructions and wear rubber gloves and protective goggles when using strong chemicals.
Never strip furniture near an open flame as stripping chemicals can ignite.
Use chemical strippers clearly marked "no cleanup" or "will wash away with water." However, the "no cleanup" type stripper may leave a residue, which must be sanded away. Residue from the "wash away" type can be removed by rinsing with water. Be aware that water may raise the grain of the wood. Lightly sand to reduce this effect.
Using a heat gun is a quick and effective method for removing the finish from flat surfaces. Heat a small area of the bench with the heat gun until the finish bubbles up. Then scrape off the residue into a plastic bag or another container to discard later.
The heat technique can leave residue in the pores of the wood or in detailed areas and crevices that can't be scraped away. If that starts to happen, stop using heat and apply a chemical stripper to finish the job.
Always wear a heavy glove on the hand you'll be using to hold the heat gun and scraper because they can get very hot.