Tool Test: 3x21-Inch Belt Sanders

By Chris Kulczycki

Publication Date: May/June 2003

Beads of sweat collect on my brow whenever I hand out belt sanders during the boat building classes I teach. In the wrong hands these powerful tools can easily do more damage -- like sanding through the hull of a boat in seconds -- than good. The same is true for belt sanders on the jobsite. A racing abrasive belt under a rookie's guidance might spell disaster for those built-ins, stair parts, or custom oak doors. After years of using these tools for installing finish work and building boats, I've learned that getting a good, flat finish is about control, and control comes from skill, experience, and good tool design. While we can't do much about your skill and experience, we did test seven 3x21-inch belt sanders: the Bosch 1274DVS, Craftsman 27725, DeWalt DW431, Hitachi SB75, Makita 9903, Porter-Cable 352VS, and Ryobi BE321 Type II. We looked for the good design features that'll help you achieve a flat, smooth surface and good performance: nice balance, comfortable handles, straight tracking, easy adjustments, and good finish quality. We also looked at power for knocking off tough materials like paint.

I worked the sanders for a month on site and in my shop on both hard and softwood projects. I used them to surface glued-up stock, remove paint and varnish, resurface a maple countertop, sand a badly weathered deck railing, and clean hardened epoxy off boat building projects. I also built a jig to test how well they reached inside corners and edges. To keep things fair, I used the same brand of 40-, 80-, and 120-grit belts on all seven machines.

Body Styles and Handles.

There are two distinct body styles in this test: low profile and traditional. The Bosch, Ryobi, and Craftsman units have motors in-line with the belt and their handles are at the far ends of the tools. The result is a long, narrow, and low-profile tool, about 1-1/2 inches more narrow than the more traditionally designed DeWalt, Hitachi, Makita, and Porter-Cable tools. These four higher-profile, more traditional designs have motors that spin transverse to the belt. Their handles also are above the belt rather than at the ends of the tool, a design resulting in a wider but shorter sander.

Though I've always used belt sanders with the traditional layout, I like the low-profile tools' balance and feel, especially for working wide, flat surfaces like a glued up panel or hardwood floor repair. The Bosch in particular is light, nicely balanced, and has well-shaped handles. Of the more traditional tools, the Porter-Cable and Makita units have exceptionally comfortable handles and well-distributed weight, although the Porter-Cable is a bit heavy. I found the DeWalt's handles a little too close together, making the tool uncomfortable to hold.

Flat Tops.

The Bosch, Craftsman, Ryobi, and higher-profile Makita sanders have flat tops so you can flip them belt-up for use as stationary tools. This is great for shaping small parts or working to a scribe line. Each of these sanders worked great when I used them upside down to work the edge of a piece of trim. This position also was excellent for minor adjustments to little pieces of base molding that I had to fit over a threshold. You can even put an edge on a chisel or flat bar for rough work with the tools in this position.

Fences.

Fences turn these belt sanders into proper little sanding stations that are great for installing built-ins, trim, or boat interiors. You can already use the Bosch belt-up, but to get even more utility out of it, the company sells optional accessory fences and hold-downs. DeWalt sells similar fences and hold-downs, making it the only traditionally designed unit with this accessory package.

Switches and Cords

For final sanding procedures like leveling a floor repair or sanding a countertop, it's handy to lower the sander's speed because it's less likely to gouge the work. All of the sanders in the group have variable-speed dials, which I like, except the Hitachi; it only has a high-and-low speed switch, which makes it more limited. The Bosch, Craftsman, Makita, and Ryobi have dials that are easy to reach when the machine is running. The DeWalt's dial is tough to reach; it's on the handle so you must move your hand to get at it. Porter-Cable's and Hitachi's speed switches are a difficult reach, too.

As for cords, when will tool companies realize we want them long? The Makita has a 16-foot cord -- kudos. The others are 6 to 9 feet long, which is too short for my liking.

Belt Release.

The metal belt-release lever on the Makita is notably easy to use. By contrast, the thin metal lever on the Hitachi is painfully sharp. I have doubts about the durability of the plastic release levers on the Craftsman, DeWalt, Porter-Cable, and Ryobi tools. While they all work as intended, they feel stiff and seem like they could snap off. The Bosch lever is particularly stiff.

Tracking and Adjustment.

Tracking is the tendency of the belt to stay centered and not wander off the rollers, as happens on some old belt sanders I have. Once in a while, as the belt wears, you might need to tweak the tracking to keep the belt centered. Also, you must reset the tracking for each new belt.

All of the belts tracked steadily once adjusted, but some of the adjustments were easier than others. On the Porter-Cable and Hitachi models, the thread pitch on the adjustment screw is too coarse, which means a small turn of the knob moves the belt too much. The rest of the tools have finer threads, so more turning is required to achieve the same result; however, you have more control and don't find yourself twisting the knob back and forth repeatedly to get the adjustment where you want it. I found that the coarser adjustments on the Porter-Cable and Hitachi, actually make it more cumbersome to adjust belt tracking precisely.

Platen and Finish Quality.

To ensure a flat finish, a sander's platen should be flat. I checked the transverse flatness of the platens with a straight edge and found most of them to be flat or slightly convex. The DeWalt, Bosch, and Makita tools are closest to perfect; the Craftsman, Hitachi, Porter-Cable, and Ryobi also are very close to flat. The Bosch unit has a composite rather than metal platen and only the Ryobi and Craftsman lack a cork or rubber backing pad under their platens. Interestingly, I didn't detect much difference in finish quality between any of the sanders when surfacing glued-up cherry; all of them left an impressive finish here and throughout the test. Bosch, DeWalt, and Makita sell optional sanding frames for their sanders. The frames (which fit around the base of the sanders) make it much easier to achieve a really flat finish and prevent gouging on large surfaces such as countertops and floors.

Yaw.

None of the sanders in this group yawed or wandered, as some older models I've used do. They all run straight and true, even when I ran them one-handed. This is particularly evident when sanding to a scribe line. The Bosch, Craftsman, and Ryobi were easiest to keep on a line. I found that their handle locations (at the far ends of the tool) allow for better control. The Makita and Hitachi also were very steady working to a line.

Power.

While I wouldn't call any of these tools underpowered, the Hitachi, Porter-Cable, and Makita definitely have extra grunt and would be my choices for heavy stock removal, hogging off paint, or knocking down a hard finish. The Craftsman, DeWalt, and Ryobi models, on the other hand, feel a bit strained when pushed hard, but were still capable.

Sanding in Corners

The Hitachi's 4-inch-wide platen design is unique. The idea behind this feature is you can track the belt to the edge of the platen to better sand flush in corners. However, I found no advantage to this design, and the 3-inch platens on the Bosch, Craftsman, Porter-Cable, and Ryobi tools did just as well. In fact, the extra width of the Hitachi gives it an awkward and bulkier feel in tight spots. The DeWalt's platen isn't flush with the right side of the sander body. The body overhangs the platen on the right side by about 7/16 inch. Since the motor overhangs the platen on the left, this means it simply can't sand flush to a wall, backsplash, or other vertical surface.

The removable front handle on the Bosch unit is a thoughtful design feature. It helps the tool fit a little closer into corners and other tight spots. DeWalt's tool has a removable front cowling that exposes the front roller. This makes it easier to work in corners, but for obvious reasons, you've got to be careful not to bump anything you'll have to go back and fix later.

Dust Ports.

Dust collection is very important to me. All of the sanders tested have dust bags. While dust bags help, I typically find that the dust pickup is marginal, so I usually attach a shop vac. Fortunately, that's easy enough to do with any of the tools in the test except the DeWalt, which has a rectangular dust port and won't accept a circular vac hose.

Dust Bags.

The bags on the Porter-Cable and Hitachi are on the right side of the machine where they blocked my view when I sanded flush into a corner, but you can see the work just fine in other positions. If you do get stuck with the bag in the way, the Porter-Cable's pivots, which helps in corners. On very rare occasions, Hitachi's must be removed for corner work, which, needless to say, generates some dust. The DeWalt's front-mounted dust bag is hard to see around whether you're in a corner or not.

The Porter-Cable, Hitachi, and Makita have the largest dust bags, which I like, because they require less emptying. The Bosch, Craftsman, and Ryobi bags are on the small side and are positioned off to the left side of the sander. They might need to be removed in some tight spots like the Hitachi's, but that's still the best place for them on these low-profile tools.

Winners

I like the Porter-Cable and Makita sanders best, but choosing between them is tough. I really like the Porter-Cable's rock-solid feel, comfortable handles, and excellent overall performance. But the Makita deserves the top honor because it too performs well but also has a longer cord, better belt-release lever, nicer tracking adjustment, and a flat top for upside-down use.

The Bosch also is a great, if very different, tool. It has nice balance, tracking, and overall feel. Being able to use it as a bench tool is a huge advantage for some work, too. The Ryobi and Craftsman are much like the Bosch and would be a good choice for the budget conscious or for more occasional use.

The Hitachi is well made and powerful, but has a few features that need improvement. The DeWalt rounds out the group.