Sanding BASICS | What you need to know about sanders and sandpaper

Sanding BASICS | What you need to know about sanders and sandpaper

Sanding can be time-consuming, tedious and one of the dustiest, messiest, most boring tasks in the woodshop. But it’s also something that you’ll have to do in just about every single project. So let’s talk about the basics and how to minimize the monotony.

Sanding and sandpaper is a big subject. Big enough that there are actually entire books devoted to the topic, but I am limiting the scope of this article and video to the most common sanding you’ll use in a home workshop.

Sanding Basics.

My Sanders

(Note: some of my tools aren’t manufactured anymore so I’ve included tools that are nearly identical.)

Sandpaper Grits

All sandpaper, whether it’s in a sheet or for a power sander, comes in various degrees of coarseness. The bigger the number, the smoother or finer, the paper. And there are a lot of grades available. All the way from a super coarse 24 grit paper for removing lots of wood fast, to ultra-fine 1200 or even higher for polishing finishes.

Thankfully, you don’t need all of them for woodworking. I recommend keeping just three on hand and in roughly these proportions: 220 and 80 grit makes up about half of my stock and 120 makes up the other half.

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I have others too, but use them only occasionally for special purposes. I would only buy say, 600 grit for something specific. Nothing you need to stock up on.  I consider 120 grit to  be the workhorse of sandpaper. It is so versatile, that you can often get by with it alone.

80 Grit Sandpaper: Shaping

Technically, 80 grit sandpaper is a medium grit, but in my shop, I consider it coarse, since I don’t use anything rougher. It’s great for quickly removing sections of wood. This is especially useful if you’ve joined a couple boards together that aren’t quite flush.

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80 grit is aggressive enough that you can use it for shaping and carving. It’s also great for rounding over sharp edges.

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Sometimes, the faces of boards may have scratches or dents which are easy to remove with coarse paper. And 80 grit is useful for stripping paint or other finishes.

120 Grit Sandpaper: The Workhorse

It might take a bit longer, but all of the sanding tasks you can do with 80 grit can also be done with 120 grit paper. For some shaping tasks it’s a better choice. Since it’s less aggressive, you can maintain better control over the smoothing. It’s a good option if you want to just ease over sharp edges.

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Unless there are major scratches, dents or uneven spots, 120 is quite often the ONLY grit of sandpaper I use on my projects once they are assembled. It’s the best of both worlds: it evens out rough areas and smooths the wood to a finish-ready surface.

There are, of course, exceptions. For instance, after sanding with 120, I will sand wood even smoother with 220 grit paper if I am going to apply an oil finish such as tung oil.

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But if you are going to apply lacquer or polyurethane, I see no need to waste time sanding the wood any finer than 120. The finish itself is what will give your project it’s silky smooth feel.

And if you are painting a project, you can relax about almost all sanding. Just sand out dents, unevenness and imperfections. The paint will do the rest.

220 Grit Sandpaper: Finishing

Keep in mind that most fine grit sandpapers are for finishing and not usually used on bare wood. Sure you can work your way through grits of sandpaper all the way up to 1200 grit if you like and your project will feel incredibly silky smooth. You’ll love it.

But, you’ll want to apply a protective finish to most projects, which will cancel out all that work. Again, an exception might be if you are applying tung oil or linseed oil which will soak into the wood. I don’t include Danish Oil here, since it is a polyurethane blend.

I use 220 grit sandpaper for sanding between coats of polyurethane finish so each layer can bond to the next.

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For lacquer, the finish I use the most, you don’t need to sand between coats since each fuses into the next. With lacquer, I lightly sand the surface with 220 paper before applying the final coat. This is very important for removing all those little bumps and dust particles you can feel when you rub your hand over the surface. This is what separates a good finish from a great feeling finish.

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Also, do the same thing for small painted projects, toys and such. Sand the paint smooth before applying the second or final coat. You’ll be amazed at how different the surface feels.

One final note about finish sanding: I like to sand by hand rather than using a power sander. It takes a light touch and I like to sand with one hand and feel the finished surface for imperfections with my other hand. A power sander is likely to sand the finish completely off.

Random Orbit Sanders

The cheapest way to sand is to buy sheets of sandpaper and sand by hand. You can wrap the sandpaper around a sanding block or just use your bare hand.

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But for most projects, hand sanding will get old really quick. Instead, consider buying a random orbit sander. This is the most useful and versatile sander you can own.

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Its motion is called random orbit because it doesn’t just spin, but also moves around in random directions, helping to prevent circular sanding scratches on your work.

It uses sandpaper discs that attach using hook and loop, or Velcro. The holes are there to suck up a lot of the sanding dust as you are sanding. It either collects in this container, or you can attach a vacuum hose.

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Sanding is easy, just flip the switch and move it around. Generally, the advice you hear it to let the weight of the sander do all the work, but sometimes if I am trying to remove a deep scratch, I find that pressing down actually seems to help. But that could just be my imagination!

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A random orbit sander can cover large surfaces pretty quickly. Check your progress with your hand until it feels smooth. Also look at the wood surface from a low angle so see any imperfections you might have missed.

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One drawback to a random orbit sander is that you can’t get into corners, say inside a cabinet. I usually sand those parts before assembling them. You can also sand them by hand or use a finishing sander like this one that has a point for getting into corners. But really, if it’s inside a cabinet or drawer, you probably don’t need to bother sanding that much anyway.

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Belt Sanders

A belt sander is super aggressive and I don’t recommend it for much woodworking. It’s very easy to gouge your work piece and often causes more damage than it’s worth. It’s best for construction projects or very rough carpentry where you need to remove a lot of material.

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One way you can use it effectively in a woodworking shop is to mount it upside down and take the workpiece to is. That will give you a lot more control.

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Benchtop Sanders

I have two benchtop sanders that are relatively inexpensive and are very handy to have. The first one is a combination strip sander/ disc sander. If you are interested in getting a benchtop sander, this is the one I recommend. It’s my go-to sander for all kinds of tasks.

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I mostly use the disk for shaping and removing material. It is especially handy for sanding off ridges left by bandsaw cuts and for sanding curved pieces down to exact lines.

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One of the main benefits is that it has a tilting table. This helps you keep your pieces square while sanding, or you can tilt it to create bevels.

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My sander has a one inch wide strip sander on the side. When I first bought this sander I thought I would hardly ever use it, but wow…it comes in very handy. You can sand wood using the table, but mostly I like to sand freehand up here for hard to reach spots and even to carve shapes. And it’s great for sharpening tools.

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There are two drawbacks to this unit. The first is that changing the discs is a real pain since it uses adhesive backed paper. You can probably guess, I only use 120 grit paper. And I just use it until there’s hardly any grit left on it! The strips are easier to switch out, but still, I only use 120 grit.

The second drawback…really just a limitation…is that you can’t sand inside curves with the disc sander.

You can wrap sandpaper around a dowel or even a can for a hand sanding solution. Or you can get  various diameter sanding drums that will fit into a drill or drill press. You can also get pretty good results with a random orbit sander if it will fit in the curve.

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A number of years ago a viewer sent me this oscillating spindle sander which makes sanding inside curves a breeze. It comes with a number of different sizes of spindles that are easy to change out. It has spinning and up & down movement to maximize all the paper and reduce circular scratch patterns in your board.

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Safety

Sanding is one of the safest power tool activities in the shop with one exception: the fine sawdust sanding creates. Whenever I am sanding, I make sure I have good airflow through my shop and attach my ShopVac to the tool. And I always wear a dust mask.

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12 COMMENTS

  1. I’m a little leary of your statement that sanders are fairly safe. They are to a degree, but belt sanders especially require some respect. I’ve seen people grind fingertips to the bone on a belt sander. And similar to a lathe, never wear loose clothing around a belt sander, as it can get caught and drag you in.

  2. Must be a little strange but I don’t mind sanding. I use a lot of reclaimed lumber (I’m a bit of a dumpster diver) and I like watching a REALLY dirty board turn into something almost like new. I do spend a fair amount of time removing screws and nails but I can provide a bit of labor for free wood. I do hate the dust though. I do not at this time have an adequate dust collection system. That is on my bucket list.

  3. The grits I use:
    60, 120 or 150, 220, 320, 400, 600, 1000, 1500, and 2000

    Granted, I generally sand bare wood to 320 (I find 220 a bit coarse), and 400 and higher are for leveling finish coats – and, of course, sharpening. A chisel or plane blade polished to 2000 grit is a wonder, though I now there are those to go to 120,000 and beyond.

  4. I use 60, 80, and 120 for most bare wood, and 400 and/or steel wool for finishing. There are exceptions.

    Now, the tools used depends on the workpiece. If have deep gouges in a small piece, I’m probably just going to run it through the planer — that much sanding is going to change your thickness anyway, and if you don’t sand the entire board evenly, you’ll end up with a wavy surface.

    The belt sander however is a very useful tool in my woodshop. I use it often on large panel glue-ups or table tops. Even with biscuit alignment seams often don’t perfectly align and a few passes with a plane, and then smooth out the plane marks with the belt sander, and then a quick pass with 60 grit on the orbital to remove belt scratches, then 80, 120 and finish.

    The other caveat to this is the type of wood you are using. If you generally work with pine, cedar, fir, or other soft woods, I would NEVER use a belt sander. You can remove a lot of material fast with 60 or 80 grit paper in soft wood.

    However, if you are working with hard woods like walnut, ash or hard maple, you will burn up your whole vacation trying to sand out gouges and ridges on a 24 x 48 panel with 80 grit paper on an orbital sander. Don’t be afraid of using your belt sander on hardwoods. Like all tools, you just have to know how to use it.

  5. This was fantastic for someone like me that is just starting out. Any chance you want to do something similar for the basics of staining?

  6. greetings from Puerto Rico. God bless you
    i want to know how tough two pieces of wood glued stays with carpenter’s glue

  7. Great article! Now you have me rethinking whether or not I need to use the higher grits on some projects. What you say makes sense. On my pen turning projects, I sometimes use exotic woods and some –Padauk for example –are very open grain. So after sanding, I’ll take my air compressor and blow out the dust before finishing. Or I’ll sometimes use denatured alcohol to wipe off dust and let it evaporate fully. I will use either a CA finish or friction polish on my pens.

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