Unlocking the Power of the Belt Sander

Ramon Valdez shares an in-depth guide to one of the most underrated tools in the woodworking shop: the belt sander. In this video, he demonstrates the proper technique for using a belt sander across a wide range of tasks, from flushing glued-up door frames and fitting drawer bottoms to sanding veneer, edge banding, narrow stock, and curved components. Whether you're a hobbyist or a professional woodworker, this video will change how you think about sanding and save you significant time at the bench. Find more woodworking content at Ramon Valdez Fine Furniture on YouTube.

TRANSCRIPT:

Hey gang, what is popping? This video is all about the incredible, versatile belt sander. I use this underrated and underutilized machine all the time for many tasks of all types. In this video I will show you the proper way to use a belt sander, and you will be amazed at how much time it cuts down on sanding.

Fitting a drawer bottom

Here I'm fitting a drawer bottom. Notice how I've clipped the corners at a 45-degree angle at the chopsaw to remove most of the bulk. Then, using my belt sander at probably 80 or 100 grit, I can quickly round those corners to fit the routed profile on the interior of the drawer box.

I'm not a big fan of grooves in a drawer box for a couple of reasons—you might check out those videos, I can leave a link in the description. But routing a rabbet to accommodate a drawer bottom this way means the drawer bottom edge is not showing, and of course it's still going to be very strong once you add some glue and clamps to hold it in place until the glue dries. Another strong key point: this method automatically squares up your drawer box.

Flushing glued-up door frames

This is really effective because of the platen—and I'm always talking about how it needs to be nice and flat. I've highlighted the platen from here to here. That's our footprint, and it's four inches wide. We can utilize that to not only sand where we want to, but also use those marks to keep from sanding where we don't want to. So we're going to sand these first, and yes, these overlapping rails will get some cross-grain scratches—but that's okay. Let me show you how this process works.

All right, in just a few seconds we're able to get the glue off and this is just about flush. I can feel a little bit of offset here—I can still see my pencil marks, so I know I haven't sanded much. This one is still showing blue and some offset, so we'll hit it one more time. The position of the door in relation to the camera is a little awkward, so I'm going to turn it around to do the left side, but normally I would just leave it in place.

You'll notice I make kind of small circles—or it doesn't really matter, you just want to keep that belt sander moving side to side. That's hugely important. Don't stop—if you stop, you're going to dig in. Truthfully, as I mentioned, it's a bit awkward. You can see my left elbow is up in the air so you can get a view. I should have put the camera on the right side, but no big shake—I need the practice. Anyway, bam, just like that, nice and flush.

Technique on narrow rails

Typically with a door your rails and stiles are a little bit wider. This is a style I've been doing where the rails are a lot narrower than the vertical stiles, and one of the rails—the top rail—will end up getting a handle. So at this stage they're pretty narrow, which makes it a little tight for the footprint of the belt sander to ride on. Typically, what I would do is start in here somewhere, then come across and let this edge sand right in here without introducing too many cross-grain scratches into this already-sanded piece.

It's a little hard to do on a narrow rail, so what I'll do is start here with very little pressure—almost having the belt sander hover, but it's not hovering, it's sitting down on the surface. You're just reducing the weight. Start the trigger there and then move to sand all of these components. The stiles and rails were pulled right off the jointer and planer and have never been sanded, so they just have light mill marks. Those come out fairly quickly. I'm using a 180-grit belt here.

Right out of the gate, you'll notice a couple of things—three things, actually. One, of course, moving the belt sander back and forth sideways. Two, goosing the throttle. And three, once I'm past that corner, I can keep the belt sander centered on that rail.

As I started sanding, I realized this belt is just polishing the surface—it's not doing a very good job. The reason is that I've been using an already-used belt to remove glue on the drawer fronts, and you can see right here at the seam where glue accumulates. It's not very effective anymore, so this one will probably get tossed. Let me get a fresher belt.

Same key points: start in the corner, goose the throttle. You'll see as I come to the other corner, I'm just moving the belt sander side to side until those two components are flush. We've introduced a few light cross-grain scratches—no big shake. This is 180 grit, so they're pretty fine. Everything looks pretty good. All the mill marks are gone, nice and flat, crisp corners. Again, we've got some cross-grain scratches in this area, and I can see some scratches going the other direction from the prior sanding stage.

If this were a wider rail, I could keep the sander right on it and bring it under this stile—just use this edge, and with a light touch, I won't dig a trench. I'll just sand out the mill marks and then blend the stile sanding marks with the rail sanding marks using an orbital sander. Remember, when we initially sanded these stiles, we were going across the rails, so the mill marks from the planer are already gone. It doesn't take much to sand in this corner area where two adjacent components meet.

Sizing and sequencing cuts

At this stage, I would cut these doors and drawer fronts to size—they're not flush at the ends and need to be sized correctly. This bottom rail— actually, I'm not sure it's the bottom anymore since I forgot to mark it because I was too worried about making a video—but I can look at the other ones, match up the grain, and figure out the orientation. Let's pretend for the sake of this video that this is the bottom rail, and that's the top.

I'll be adding some handles. This handle is 3/16-inch, so I'll subtract 3/16 off that distance. When sizing the door, I'll start with these cuts first. The reason is that if there's any chip-out when I make these cuts, it takes that chip-out off. Sequence of cuts is always important. I don't want to start with these cuts here, because then when I make this cut, there's a tendency for small chip-out, and I'm talking small chips, but it all adds up. It's the accumulation of all those little details that makes a big difference in the end.

All right, the handles are glued on. You'll notice zero glue squeeze-out in there. When I put the handle on, I chase it in this direction—I place this edge first and bring it this way, which pushes all the glue forward. That glue and the little overhang on the handle got cut off at the table saw with a rip fence, so everything is flush. This rail has been sanded as well as these corners, so it's finish-sanded. The panel is finish-sanded. Now we'll start on the back side, get everything finish-sanded, then finish-sand the handle, the rest of the frame, and the edges—and we're done.

I know that sounds like a lot, but it's really not. Essentially, what I'm doing is: once everything is glued up, I rough-sand with a 180-grit belt sander to remove glue, flush everything up, and get rid of mill marks. Then I cut the door to size—because you might bang or scratch it on the sliding table saw. Once it's cut to size, I bring everything back and finish-sand with a DA at 180 grit. That's about as high as I go. Really, it's just two sanding steps to get these doors nice and smooth.

Sanding grits and finish types

Nobody likes sanding—me included—and with two steps I can get everything accomplished. Since I'm using a top-coat finish, usually conversion varnish or lacquer, I don't need to go crazy smooth. I actually don't want it too smooth, because I need a little tooth for the lacquer or conversion varnish to bond. However, if you're using an oil-type finish—something called a penetrating oil, not a film finish—then yes, you can sand higher: 320, 400, 600, as high as you want. Those types of finishes soak into the wood, and the wood itself needs to be smooth. With a top-coat finish, the finish itself is what becomes smooth. Hope that makes sense.

Sanding small parts and dividers

So I'm adding some little dividers to a shop drawer. They're a little thicker than I wanted, but it won't matter. I had some old drawer stock—when I make drawers, I just make long lengths and edge-band them, and for some reason, these ones weren't sanded, so there are saw marks on them. I just ganged four of them together, and I can quickly sand them all at once. The edge banding is typically pre-sanded, but this way is quick and easy—all the parts come out the same height, and everything gets sanded smoothly.

Perfect. And here is what those little pieces were for—just some dividers in a shop drawer. I love this thing. I use it all the time. Although I have a bigger edge sander, I have more available grit sizes with this one. I do have plans for it on my website—I'll leave a link in the description. It may not fit your particular belt sander since this is the Makita 9401, but it will give you the idea of how to make one. You'll love it.

Using a bench dog as a registration point

So this is kind of an L-shaped, two-part assembly with a drawer front and a handle. I just wanted to show you a couple of things. Notice this bench dog—I'm using it as a reference point where I place this handle. It aligns with the back, so when the belt sander is blocking my view, I know where the back end of my pad is. In the front, it's easier to see, but in the back, I don't really know where I'm at, and I don't want to tip and round over that back edge. By using that dog, I can keep track of where I am. Belt sander tricks, man—got to love them.

Grinding down protruding screws

All right, hear that? No, not the air compressor—those protruding screws. We can get those flush easily with a belt sander. And before you want to give me grief about starting a fire with sparks and sawdust—look, we've been doing it like this for over 40 years, and there's never been an issue. Not saying there couldn't be, I'm just saying there hasn't been, and I'm going to keep doing it this way. If you want to feel better about it, you could probably disconnect your vacuum—so that's an option.

Chamfers, edge banding, and shop cabinet work

Now, this ugly thing is actually a shop cabinet. I want to put a heavy chamfer on the bottom so that if your boot goes underneath or a hose gets caught, it's not going to chip that bottom edge. Yes, you could use a router—this is how I do it. It's fast, easy, you'll never know it's not a perfect 45-degree angle, and it's very effective.

Same cabinet, up on top. I didn't want pocket holes showing up there, so I just glued this into a rabbet. I've got a bunch of glue in the way. I'm using an old belt, probably 100 or 120 grit—we can knock that down flush and then keep going to get that edging flush with the top surface. Belt sander is king for stuff like this.

Now, sanding across the grain with the front of the belt sander sticking over the cabinet is the quickest way to get things flush, but it's also going to introduce the most scratches. So I can turn it at a slight angle, and then as I get closer to being done, I can sand more with the grain—and boom, everything's nice and flush and looking good.

Sanding a blade storage box

I'm working on this blade box, and I've got a few saw marks on some of the edging. It's very slight, but there are some areas that aren't quite flush and a little bit of glue. There are a lot of ways to clean that up—I'm going to use a belt sander. I'll start with the grain direction here, coming across the vertical grain on the sides. To start, I just put the sander in place and pull the trigger. By starting at the corner, that's your base point—you can register flat. And even though this material is about 19mm (3/4-inch) wide, not very wide, you can still balance that big old beast on that narrow edge. As I roll into the other corner, same thing—I'm keeping the sander moving and establishing flat right on the corner. I'll do that all the way around and then hit it with something like an orbital.

So yeah, sanding doesn't have to be a crazy long procedure. I start with a 180-grit belt sander and finish with 180-grit DA or orbital. Super easy—that's how you do it. And here's the finished product: a movable blade storage cabinet. You may have noticed I just numbered my drawers rather than writing the blade size and tooth configuration on them. I know that will change over the years, so I just made a cheat sheet.

Flushing up a workbench assembly

All right, to keep the audience from falling asleep here, I'm going to speed up the video, but I'm doing the same thing—establishing flat at the corners and rolling around. Here, I just need to sand everything flush. I don't need it pretty; this is going to get a countertop on top. I just need all these components to be flush with each other.

I love this thing—this is my Panther router cart. You may have seen the video on it. I don't know why it took me so long to make it. I guess I kept using the router and coming up with new ideas, so I wanted to make sure all the features were included. There's lots of storage in the front, and on the right end, I have a drawer that pulls out for more storage. I can also add this folding platform—I made it foldable so I could fit it inside one of the drawers. It indexes into some cleats and gives me a nice surface to collect more stuff—yes, another horizontal surface. I can also add this fence off my band saw, attach the black extension, and now I have a level support for long pieces. Works excellent.

Sanding thin veneer on a dashboard project

So I think you can see—it may not show up perfectly on camera—but these are just slightly proud. You can see little shadows from the low-raking light, and I just need to get that flush, clean up the glue, and get everything smooth without going too deep. The engraving is pretty deep, but this veneer is 1/42 of an inch, so we need to be really careful. The best tool for this job is the belt sander.

You can see that I'm being super careful—I believe I have a 180-grit belt on there and I'm goosing the throttle, checking it, running it again. I don't want to take too much off. Just takes patience at this point. I don't want to remove all the pencil marks, just most of them. The belt sander is going to sand everything flat. If I were doing this with a DA or orbital, the edges would get rounded, and it's also easy to burn through.

Here, the video is slightly sped up, but you can still see the technique. Everyone knows about adding pencil marks to keep track—if you can still see your pencil marks, you know you're not going to burn through that veneer. And that low-raking light is a massive help.

I think you can see with the low-raking light that everything is just about perfectly flushed up. You can still see some pencil marks—there's one going right across where it says "Wipers." There's some glue here and there that'll all get cleaned up with the DA. This one I already did, and the letters look a little cloudy at this point — that's just because they're full of sawdust. I think it'll all blow out with air. That's what I call success.

If you didn't see the YouTube video, this is a replica—a kit car—of a Jaguar. 1943, Duke, something like that. Here are some finish shots of the dash. This is my father-in-law, Steve Brooks. The sun was starting to set, so it cast a nice amber tone. It's curly maple, the dash fit perfectly, and it turned out beautifully.

Flushing solid wood edge banding

Nothing too tricky here, but this is my favorite way to flush up a solid wood banding onto a substrate. I'll just mark some pencil lines—I'm only going to sand that area, I don't want to distort that panel at all. There's a little bit of glue sticking out, and the edge banding is slightly proud. You'll notice how I let the belt sander ride right at the tipping point, sticking over that front edge—that ensures the back wheel doesn't dig in. Super important and very effective.

Occasionally, I get the question: Why not use a lipping planer? Well, you could, but you would still have to sand to get things perfectly flush. Plus, you want a little bit of scuff for the glue to bond the veneer. So the belt sander handles it all in one step.

Sanding narrow stock and solid walnut pieces

Here we have some solid walnut—these were a pair of domino docks I gave away on Instagram. Yes, that top edge could be hit with a hand plane, and that would be very effective. But this video is all about the belt sander, so I'm showing you a way to get that smooth, get rid of any mill marks, with the component just about flush with the top of the bench. We can use pencil marks on the bench as training wheels. Balancing on about 3/4 inch (19mm) can be a little tricky, but with those pencil marks, I know I'm not going to lean over too far.

These four pieces of wood are part of the lug draws for Steve's Jaguar—solid walnut and maple. The maple in the center is about 1/4 inch thick (6.5mm), and underneath are strategically placed T-nuts that will grab bolts coming in from underneath, so all the fasteners are nicely hidden. The original design had carriage bolts going through the face, and we thought, nah, we can do better than that. The originals were also just oak and not inlaid—but this is for my eccentric father-in-law. I don't have a finished shot of these, but I can assure you they came out beautiful, and everything was flushed up with a simple belt sander.

Sanding curved shelf edges in a batch

Here's an older video of some shelves I added to a customer's bed. The goal was to quickly sand all of these radiuses, make everything consistent, and keep the edges square. Ganging them together and clamping is the easiest way to do it with a belt sander. Notice when I come around the corner and onto the flat area, I'm establishing flat with the belt sander flat on the flat area—that means everything is nice and true. Then I can roll back around to sand the curve nice and smooth, and just like that, I have six of them done with all the edges true at 90 degrees.

Keeping narrow stock flat

Getting narrow components smooth will not happen with a DA—don't kid yourself. Put a straightedge on a narrow board after you've hit it with a DA, and you will notice the edges are rounded. With a belt sander, all you have to do is find that balance point, and you can make that stock beautifully flat and smooth. Look closely here, and you can faintly see the pencil marks sanded pretty much even all the way across—that way I know I'm not tipping one way or the other.

Yes, another way to do this—and one I use often—is with a hand plane, but this video is not about hand planes. It's about belt sanders.

Wrapping up

All right, those narrow components made up this little tray, and I am so excited to share that entire project with you—so be sure to come back for that. Make sure you're subscribed if you're not already. Thanks a ton for watching.