Strip, smooth and scuff. The three essential sanding stages have not changed over the years, and they are the keys to a great end result when it comes to refinishing wood. But here’s the good news: There are lots of innovative products to make the job easier and safer – and help you get an amazing finish.
Before you begin, protect floors and other surfaces with a leak-proof, puncture-and solvent-resistant runner. For added safety, choose a floor runner that grips and stays in place yet is repositionable. Also, make sure it is slip-resistant when wet.
Next, protect yourself with a NIOSH-approved disposable respirator and, if needed, protective eyewear. Choose a respirator that is rated N95 (at least 95 percent filtering efficiency) and is designed for sanding. There are a couple of options with disposable respirators:
The important thing is to have effective protection against particles related to nonharmful dusts that are created during the sanding process. Today’s disposable respirators promote easy breathing while being lightweight and comfortable to wear, so there’s no reason to sand without protecting your health. It’s also a good idea to wear eye protection if a lot of dust will be generated or flying particles could be an issue.
If the surface is painted, be sure to check for lead before you sand – especially if any of the surfaces were painted before 1978. Traditionally this has been an involved test, but now there are disposable EPA-recognized swabs, and the entire test takes only about 30 seconds. Just swab the surface, and if the swab turns red – red means lead. Remember, it is important to check all coating layers and to always review directions included in the kit. If the surface is coated with lead-based paint, follow EPA-issued lead-safe work practices while stripping and disposing of all contaminated materials.
To strip to a bare surface, use a professional-grade 60-80 grit abrasive. You’ve got a lot of options, from sanding sponges and pads to sanding sheets to specially developed abrasive coatings and minerals. Today’s sophisticated sanding products are designed to cut faster, load less and finish finer on curves and details. All of these advancements go a long way to increase ease of use and productivity.
Abrasive sponges are great for getting into nooks and crannies and working with detailed woodwork. To strip a surface or smooth out a bump, though, it’s hard to beat a folded sanding sheet and good hand-sanding technique. We’ve been hand sanding for over 100 years, yet only recently have we seen sandpaper with the back of the sheet treated with an “antislip” coating, so it stays put when folded and gives you more control. This helps reduce hand fatigue because the abrasive sheet is not slipping and sliding as you sand. Because of this technology, you’ll be able to sand longer and cover more area with less fatigue, while maximizing the use of each sheet.
Once the original coating is off, smooth the surface to remove defects, using a 100-150 grit smoothing abrasive. Remember to always sand in the direction of the wood grain. Use a tack cloth to remove all traces of sanding dust from the surface and run your fingers across it to feel for bumps or divots. Brushing or wiping the surface with an ordinary cloth is not enough, because even the smallest amount of dust can leave a defect in the finish.
When you feel sure the surface is smooth and as defect-free as possible, scuff it using a 180-320 grit abrasive before applying a coating – and between coats. This helps ensure maximum adhesion of the coating to the wood and to the previous coat. Make sure the coating is fully cured before scuffing between coats (so it powders rather than gums), and use a tack cloth to remove every speck of dust before applying the next coat. This is your path to velvety smooth, evenly coated, beautifully refinished wood.
On woods with large pores like oak, mahogany and ash, increase pressure during stain application to work the stain into the pores. Apply a liberal amount of stain, remove any excess with a dry cloth, wait until the surface dries, then sand it and tack cloth it before applying another coat of stain or adding a layer of varnish.
There could be a fourth “S” added to the stages of sanding – smile. There’s simply nothing more satisfying than coaxing out the beauty of flawlessly refinished wood. All the prep work pays off, as your customers will agree. APC
Lynn Ogburn and Bill Ryan are marketing managers for 3M.