I’ve recently had the pleasure of watching the video The Way to Woodwork: Step-by-Step to a Perfect Finish, which was graciously provided by our friends over at the Woodworker’s Journal and Rockler. I wanted to share some of the great sanding tips that the video had to offer, along with a few of my own. But, before we begin the long journey to sanding perfection, you might want to eat some spinach first. Your forearm is going to look like Popeye’s once you’ve done all that sanding by hand.
Before You Start Sanding
Before you break out the sandpaper, it’s important to prep the area first. It’s always a good idea to break out some nice sailor tattoos like an anchor, skull and crossbones or a pirate ship for when your Popeye arm starts to grow strong. But it’s also a good idea to get your sanding tools and paper in order before you begin. I like to put my three sanding papers in a nice little row so I don’t mess up on the sanding order.
What’s the sanding order you ask? Why, it’s the sequence of differing grits that you use to create a fine finish on the wood. I prefer to start with an 80 grit sandpaper to remove the rough spots first. Then I transition to a 120 grit to knock down the lines from the rougher 80 grit. Finally, I smooth it all out with the 180 grit sandpaper. However, for softer woods, it’s a good idea to use a combination like 100, 150, and 220. But before you get your sanding arm tuned up, check for glue first.
Glue is the enemy of the finishing woodworker and more than likely, you’re going to find it somewhere. Sometimes it’s feasible to finish the materials prior to gluing them, so that once the glue dries, you can easily peel off any excess dried glue without hindering the finish.
But when you can’t finish before you glue, it’s important to check the wood for glue spots before you stain or finish, because if you don’t, they’ll show right through your finish. So how do you find out if there’s glue on your wood when the stuff is nearly invisible once dried?
I used to take a flashlight or other bright light to find these hidden imperfections when the light reflects off the shiny surface of the dried glue. But after watching Step-by-Step to a Perfect Finish, I found out there’s an easier way. Just rub the board down with some mineral spirits prior to sanding. If there’s any glue to be found, it will stick out like a sore thumb. Scrape or sand it away before you break out the stain or finish.
The Secret to a Good Sanding
One of the biggest issues I’ve ever had with sanding is when I go overboard and get a little nuts on the sanding. Either I sand too much off or not enough. But after watching the DVD, I found out what my problem was (at least my sanding problems). I wasn’t performing the sanding sequence correctly. Each step has its own reasons for using that particular grit and if you get too crazy on one phase of the process, the end result isn’t going to be the best it could be.
The idea behind using the rough grit sandpaper first is to remove any machine marks, level the materials and to set up the material for the next sanding stage. When sanding with 80-100 grit for the first stage, it’s a good idea to sand diagonally across the grain.
I know, I know. You’ve ALWAYS been told to sand with the grain. But that’s really only necessary during the final sanding stage. Going diagonally at first helps to knock down the rough spots easier and makes the job go much faster. Once you’ve removed the bad spots and made the surface flat, stop sanding! Unless you like the look of a huge forearm.
The objective behind the second pass is to remove the scratch marks from the first pass with the next higher grit. You don’t have to spend a long time messing around with this sanding stage either. Just be sure that you knock down the old scratch marks with your new ones and sand in the opposite diagonal direction during this pass. Once you’ve made your way across the material, stop and move to the next sanding phase.
This final step is just as easy. Continue in a diagonal direction (opposite from the last pass) and knock down the lines from the last sanding pass with the highest grit of sandpaper. Once you’ve got that taken care of, a quick pass with the grain of the wood and your project should be nice and smooth.
Alright, so you don’t want muscles like Popeye. That’s where a power sanding tool comes in handy. But one of the biggest mistakes made when sanding with these power tools is that the user tends to bear down on the tool too hard and make really quick passes. That’s a big no-no when it comes to sanding. You’re going to slow down the tool in the process making it take a lot longer than it should and you’re going to get telltale swirling marks in the woods surface affectionately called “pigtails”.
The best way to sand with a power tool is to let the tool do the work. Don’t press down on the tool at all, just let its own weight do the work for you. My other tip is to go slow. Move the tool about one inch every second for a good sanding without lots of passes. Be sure to change your sandpaper from the lower grit to the higher grit as your sanding sequence progresses and you can’t go wrong. Happy sanding!
If you’re interested in more great finishing tips (the few mentioned here are just the tip of the iceberg), take a look at this video from the Woodworker’s Journal The Way to Woodwork: Step-by-Step to a Perfect Finish. There are some unbelievable tips and techniques that are sure to give you the perfect finish every time. All photos courtesy of the Woodworker’s Journal.