Lose The Sandpaper, Grab The Razor
By Scott Wunder | Posted: 11/24/2013 11:56AM
One of the best finishing tips I’ve ever picked up came from an episode of “This Old House.”
Norm and Tommy were building some cabinets for a house, and they were spraying a lot of plywood. They showed how they used a razor as a scraper to knock off the nubs between finish coats. It looked simple, so I gave it a go, and I haven’t looked back since.
Hold the razor almost vertical and then lean the top the direction that you push. After about 3 seconds you will get the feel. Let me first start by saying that the razor isn’t perfect. It is flat and straight, so it doesn’t work for profiled edges or rustic, wavy surfaces, but it is great for big, open flat spots. I use it most often on sheets of plywood, but also use it on the flat spots of doors, including the stiles and rails.
The beauty of the razor is the simplicity and speed. With one razor blade, I can quickly smooth a surface between coats on a job that would eat up several sheets of sandpaper. The big difference is that the razor doesn’t clog up with finish like sandpaper does, it just scrapes off the high spots. This is especially helpful when I am trying to finish a job in just one day (which is usually the case). As long as the finish is set up enough to handle, I can start scraping with a razor and never have to stop. In the same scenario with sandpaper, it would clog almost immediately causing me to use more sandpaper and not get consistent results. The clogged sandpaper also tends to drop off little boogers of coagulated finish that stick to the surface. That never happens with a razor.
Using the razor is simple. Hold it up nearly vertical to the surface, lean the top into the cut and pull or push the direction you want to go. It works just like a cabinet scraper, only on a smaller scale, and it doesn’t need to be sharpened. When the razor is dull, just grab another one and move on. I often flip the blade around and cut the opposite direction to make the edge last even longer. If it feels like it isn’t cutting, flip it around. If it still isn’t cutting, just grab another one and get back to work.
Quick tips for using a razor:
- Make sure the finish is dry before scraping.
- Make sure runs are super dry before scraping. The finish should scrape off in shallow layers, not rub off in big chunks.
- Always use a new razor. Old razors can have nicks that scratch the finish.
- Use a razor on flat surfaces. Razors do not work on profiled edges.
- Watch the sharp corners. The corners of the razor can easily scratch the finish.
- Use a light pressure to start. Apply more pressure as you get more comfortable.
About the Author
Scott WunderFrom felling the trees through installation of the final piece Scott Wunder, owner of WunderWoods in St. Charles, MO, shares his woodworking knowledge with anyone that will talk to him about wood. Whether you want to learn about milling lumber or need help on a project, get your fill of woodworking infotainment at WunderWoods.com. Scott writes about all aspects of woodworking and specializes in finishing (mostly because no one else likes to sand). Scott can be reached at firstname.lastname@example.org. Check out Wunderwoods' website at Wunderwoods.com.