Woodworking: How to use a sander and common mistakes

Sanders are used to smoothen the surface of your project so that you can create a clean, smooth finish. Sanders are very easy tools to use, and I’ve even let my 7-year-old cousin use a random orbital sander under my supervision.

However, sanders can be used incorrectly that will reduce the efficiency, effectiveness, and the sander’s life.


How to choose the right sandpaper

Before using the sander, you need to choose the right sandpaper. The sandpaper is arguably the most important part and more important than the technique itself.

To learn more about what to look for when choosing sandpaper, check out my article “Sander complete guide”.

Dry sandpaper grit ranges from 40-400 grit while wet-dry sandpaper ranges from 100 to 3000+ grit.

General woodworking projects

For most woodworking projects with unfinished wood, I use 120 grit, 220 grit, and then 320 grit sandpaper. Then I stain or paint and lightly sand using 320 grit sandpaper in-between coats, if it calls for it.

120 grit is used to take out major imperfections like wood splintering. You will know that you sanded enough if the wood feels slightly smooth and it doesn’t have a lot of splintering.

Note: 120 grit can be skipped for most plywood and pre-sanded plywood.

220 grit smoothens the wood further and is a gateway to finer sanding grits. You may not notice a huge difference but using 220 before 320 will make the transition smoother and will require less sandpaper.

320 grit sandpaper is the final step for most woodworking projects. The surface will feel smooth to the touch, but it will not be too smooth to where paint will not adhere to the wood.

Once you have sanded with 320 grit sandpaper, you are ready to move to the finishing.

To learn how to finish wood with paint or stain, check out my article here.

Removing varnish or paint

Most paint can be removed using 80 grit sandpaper. Varnish will likely need 40 grit sandpaper to start out with.

If 40 grit sandpaper does not seem to work, then you may need a paint stripper.

In my experience, I have tried 3 paint strippers, Citristrip, Jasco paint remover, and Klean strip paint stripper. Citristrip worked the best but was the messiest out of the 3.

Purchase Citristrip paint stripper: Amazon link

To learn more about the paint strippers, then you can check out my article here.

Wet sanding and polishing

Wet sanding is commonly used to create a mirror or highly glossy finish on the project. Wet sanding is commonly used in guitar and piano projects along with tables and other furniture when working with wood. Outside of wooden projects, wet sanding is commonly used in automotives.

Wet sanding is done after the protective coat is applied, like polyurethane, epoxy, or 2k clear coat.

Wet dry sandpaper ranges from 600 to 3000 grit.

When wet sanding, after you have ensured that you have enough clear coat, you can start with 600 grit and work your way up.

The finer the grit, the more polished the finish… generally.

Go to my article “Wet sanding” to learn more about wet sanding techniques to get a mirror-like effect.

How to use a random orbital sander

A random orbital sander is designed to prevent swirl marks and burning through sections of the wood.

  1. Get correct sandpaper
  2. Attach sandpaper to sander
    • When attaching sandpaper to a random orbital sander, you want to ensure the fabric side is facing the Velcro of the sander.
    • Align the holes of the sandpaper so they go over the holes on the sander.
      • This will allow for the wood dust to be blown into the dust collector and not pile on the workpiece.
  3. Lay sander on surface
    • Place the sander flat on the workpiece and grip it firmly with your hand
  4. Turn the sander on
  5. Move sander in a linear motion
    • Move the sander in a linear motion overlapping 50% with each pass.
    • Allow the sander to do most of the work for you
      • Do not press down on the sander, only use your hand weight.
      • Do not move the sander too fast or too slow.

How to use a block sander

  • Get correct sandpaper
  • Attach it to sander
    • If the sandpaper needs to be cut, cut it so you have enough sandpaper to tuck into the groove or clamp
    • Depending on the sander, you will need either tuck the sandpaper in the groove, clamp it, or hold it firmly with your hands
  • Sand in a forward and backward motion
    • Apply light pressure and prioritize quickness over force

How do you know if you sanded enough

Generally, 3 passes are enough when sanding, before moving to the next grit. This works because you move in increments instead of jumping to the highest grit.

You will not feel a huge difference between the grits, but if you trust the process, you will have a smooth finish in the end.

Sanding by hand vs with sander

Hand sandingPower sanding
Project typesDelicate and thin finishesGeneral projects and removing finishes

When to sand by hand

Sand by hand definitely takes longer than using a power sander and you are more prone to having imperfections, like scratches.

Hand sanding is cheaper than power sanding. Hand sanders range from 3 to 15 dollars.

Hand sanders are ideal for delicate projects and sanding between fine wood finishes. Hand sanders are also ideal for wet sanding a topcoat since you have fully control how lightly and slowly you sand.

When to use a power sander

Power sanders are much more efficient than hand sanders, but they cost more.

Power sanders are ideal for most woodworking projects and when sanding bare wood.

Sander common mistakes

Starting sander before placing it on the wood

Importance: ★☆☆☆☆

You are unlikely to have the sander perfectly flat when you place it on the wood. The side of the sander that touches the wood first will be sanded slightly more.

This is not a huge deal in most woodworking projects, but it is very important if you want a mirror finish.

Keeping sander in the same spot

Importance: ★★★★☆

You should be constantly moving the sander. Keeping the sander in the same spot will result in burning through the wood quicker than expected.

Sanding hard to reach spots by tilting sander

Importance: ★★☆☆☆

Many people use the edge of the sander to get to those tough spots. If you overlap your passes 50 percent, then you will uniformly sand the wood down.

Pressing too hard on the sander

Importance: ★★★★☆

Pressing down on the sander overworks the motor and reduces the sander rotations. Let the sander do the work for you.

Skipping sanding grits

Importance: ★★★☆☆

Jumping straight to the highest grit will not get you the smoothest finish. Additionally, you will use more sandpaper and it will take more time

Not overlapping passes

Importance: ★★★★☆

Not overlapping your passes will result in gaps and uneven sanding results. That it because, with orbital sanders, the edges sand slightly deeper than the center.

Not cleaning sander or removing dust

Importance: ★★★★☆

Letting saw dust build up on the workpiece and in the sander will overwork the motor and reduce efficiency because you are moving around loose dust and not actually sanding.

Sanding wet wood

Importance: ★★★★☆

Sanding wet wood will cause more wood to be removed and the sandpaper essentially “burning through” the wood.


In this article, we learned how to use a sander and how to pick the right sandpaper for your project. We also discussed sanding by hand vs using a sander and common sander mistakes.

Thank you so much for taking the time to read this article and I wish you luck on your woodworking journeys!


My name is Rachel Blanding and I am a woodworker. I started woodworking at the beginning of the COVID-19 pandemic. I mainly create and refurbish furniture and create art. In this site I will share with you the knowledge I have gained over the years, and what worked for me and what didn't.

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