Quick Hits: Proper Sanding

Sanding is a critical step in woodworking that can significantly impact the final appearance and quality of your project. It’s not the most glamorous part of woodworking, but it’s essential for achieving a smooth, ready-to-finish surface. This guide will walk you through the process of sanding, from the tools you need to the techniques for getting the best results. Again, this isn’t typically fun but it’s one of the only times you can almost run on autopilot. 

Essential Sanding Tools

1. Random Orbit Sander: This power tool is a must-have for any woodworker. It combines the speed and aggressiveness of a belt sander with the ability to produce a finer finish. Remember not to push down too hard on a random orbit sander as it can cause the sander to stop spinning as it should.
2. Hand Sanding Block: For the final grit, it’s always a good idea to sand by hand with a sanding block, moving with the grain. This will ensure you get rid of the last of the swirl marks that a power sander may leave behind.
3. Vacuum Clamps: Vacuum clamps are handy as they allow you to sand without constantly having to clamp and re-clamp. This is particularly useful when you’re running through different grits.
4. Spindle Sander: A spindle sander works on inside curves. It comes with all different size diameter spindles and the sandpaper comes in tubes that slide down onto them.
5. Detail Sander: A detail sander picks up where your random orbit sander leaves off. It can get into tight corners because of its pointy tip but also because it’s lightweight.
6. Belt Sander: A handheld belt sander is probably the most aggressive sander in the shop. Its main purpose is for removing lots of material fast.

Sandpaper Selection

The type of sandpaper you use can make a difference. Aluminum oxide sandpaper is more durable and lasts longer. Silicon carbide is another option, especially for sanding sheets over 400 grit. Avoid buying the cheapest paper on the market. Good paper is made from good long-lasting materials.

Grit Selection

The grit of the sandpaper you choose depends on the finish you’re using. The deeper the scratches left in the wood, the darker your stains or dyes will be. If you hope to add a fair amount of color, you may go from 80 to 120 to 150 and stop. If you want a little less color, you may go from 80 to 120 to 180 instead of 150.

Sanding Techniques

1. Avoid Over-Sanding: Over-sanding can occur when you’re trying to make uneven joints flush. If you sand too much in one area, you can end up with a cupped board. To avoid this, make sure you sand equally along the length of the board. Making a pencil mark along the entire board can help. Sand until it disappears evenly.
2. Start with Lower Grits: Start with a lower grit sandpaper, such as 80 grit, and gradually move up to higher grits. This helps to remove larger scratches and imperfections first, and then refine the surface as you progress.
3. Reposition Your Project: To avoid bias towards one side, keep repositioning your project. This ensures even sanding throughout the process.
4. Have Good Dust Collection: Good dust collection is important not just for health reasons, but also because allowing dust to build up beneath the sander can cause those little pigtail scratches that look awful under finish.
5. Be Careful with Plywood: When you buy that nice oak or maple or birch plywood, you have to be careful not to sand through the ultra-thin veneer on the outside. Don’t use anything more aggressive than 180 grit on veneered plywood and be careful with that.

Final Thoughts

Sanding is a process that requires patience and attention to detail. While it may seem tedious, the time and effort you put into properly sanding your project will be evident in the final product. Remember, the key to a perfect finish is not to rush the process and make sure to eliminate all scratches before moving on to the next step. With these tips and techniques, you’re well on your way to achieving a professional-looking finish on your woodworking project.