Rabbets, Dadoes, and Grooves Use Your Router to Master the Building Blocks of Basic Joinery

joinery made simple Rabbets, Dadoes, and Grooves Use your router to master the building blocks of basic joinery

By Craig Bentzley

Rabbets, dadoes, and grooves are Better?” on page XX), you’ll discover that the router essential joints, used in most furniture and is the most efficient and least expensive way to get cabinet projects. They also rank among the easiest started. While a hand-held router excels in some joints to make provided you have the right tools. So, cases, a table-mounted router may have the edge in if you’re fairly new to woodworking, or you need to others, providing more accuracy, stability, and safety. brush up on your skills, here’s your chance to master We’ll cover both approaches. After the dust settles, these three “building block” joints and achieve cleaner, you’ll have the confidence you need to machine more accurate cuts every time. dead-on, snug-fitting joints for any number of Though other tools can fashion rabbets, dadoes, project assignments. and grooves (see “Router or Table Saw: Which Is

Right-on rabbets

A rabbet is a two-sided, open- easily and accurately. Second, ended recess that runs along the it creates more gluing surface, DEPTH edge or end of a board as shown providing greater load-bearing in Figure 1. Typically, you’d capability than a butt joint. That WIDTH size the rabbet to accommodate said, glued rabbet joints offer the thickness of mating shelves, little in the way of strength and cabinet backs, and glass in a picture usually need to be reinforced frame or door. You’ll also find with nails or screws. As a rule of them in shiplapped backboards thumb, never exceed two-thirds and overlapping cabinet doors. of the stock thickness when Fig. 1 Occasionally, you’ll even see them in determining a rabbet’s depth. the construction of utility drawers. smaller rabbets having widths and A nthony aul In addition to speedy machining Rabbets with a depths that match up with a common P and assembly, a rabbet joint offers hand-held router rabbet bit set, setup is easy. (See “A

several advantages over a butt joint. A hand-held router provides the most Bigger Bit Bang for Your Buck,” page photos: First, it enables mating parts to align common way to cut rabbets. For XX). Just select the right bearing, set

14 woodcraft magazine A p r i l /M a y 2 0 0 8 your depth of cut, and go at it. Things get trickier when making wider or Rabbets, deeper rabbets. Here you’ll need to use a larger straight bit and an edge guide feed direction accessory, or a straightedge clamped to Dadoes, your workpiece. Some manufacturers’ edge guides have large openings that can’t be adjusted (Photo A). This can B scrap hamper registration with the edge of and the stock at the beginning of the cut. A You can close this gap by attaching Clamp boards side-by-side to create a longer bearing surface for the edge guide. wood strips to the edge of the guide. If Make wide rabbets with a large Scrap placed where the bit exits the wood Grooves you don’t have an edge guide, you can straight bit and an edge guide. prevents tear-out. screw or clamp a piece of wood to your router’s subbase. Regardless of your setup, make sure your workpiece is secured with clamps, double-faced tape, or other means, so it doesn’t move during the cut. Note, too, that the direction of feed is always left to right when doing hand-held rabbeting. Add scrap at the exiting end of the workpiece to eliminate tear-out as shown in Photo B. Rout end grain before edge grain; and, for the best cut quality, don’t remove more than 1/8" of material in a pass. If you have 1 C bearing D a fixed-base router, you can place /8" hardboard strips under the router base and remove one after each pass until A rabbet bit with a bearing is the When making end rabbets, a squared you achieve the desired depth. For best choice for cutting rabbets cutoff can provide backup and prevent on curved edges. rabbeting curved stock, see Photo C. tear-out at the end of the cut.

Rabbets on the router table when you need to make multiples. should always be from right to left, and Although you can do most rabbeting Here, with one setup, you can for the best quality cuts, never remove with a hand-held router, certain dispense with the large assignment in more than 1/8" of material per pass. applications call for a table-mounted short order. Follow your workpiece with sacrificial router. Some examples: small projects When working on the router table, scrap as shown in Photo D. (like jewelry boxes), picture frames, and remember that your feed direction

Router or Table Saw: Which Is Better? Straight bits can cause tear-out at the edge of the cut. While a table saw can cut most of the joints featured here, several issues come into play. First As an alternative to is cost. A quality dado set is expensive (up to $300). Also, some saws do not have arbors long using a sacrificial

enough to hold a complete dado set. To cut rabbets, you need to attach an auxiliary wood face t piece of scrap as to the fence to “bury” the unneeded portion of the dado set. You’ll also need a dedicated zero- r in Photo B, make clearance insert for each setup you use whether you’re cutting rabbets or dadoes. A dedicated a pass from right sled is best for dadoing large parts, and stopped dadoes made on the table saw require a lot of to left, taking 1/16"

handwork to clean them up. Also don’t forget that dado sets take valuable shop time to set up. ale tip of the material off. If you have a lot of joints to make, setting up a table saw is probably worth the effort. One After making this advantage: You can make wider and deeper cuts in one pass. This saves time in the long haul. “climb-cutting” skim pass, rout Still, when you only have a few rabbets or dadoes to make, a router will get you to the finish line from left to right to much faster. finish the rabbet.

w w w . W o o d c r a f t M a g a z i n e . c o m woodcraft magazine 15 joinery made simple

Cutting sharp, clean dadoes

Dadoes For Plywood

3 As you may already know, /4" plywood does not typically 3 measure /4" thick. The same 1 holds true for /2" plywood. Although it might not seem like much, the difference can result in a sloppy fit in a case piece (Photo G). To make a snug dado or groove for undersized plywood, take two passes with a smaller bit, or rout a shallow Fig. 2 Fig. 3 rabbet along the edge of the mating piece on the hidden face. Perhaps the best option: A dado is a square-sided, flat- accordingly. Normally, dadoes are Use an “undersized” router bit bottomed recess that runs across made no deeper than one-half of the that manufacturers created to the grain as shown in Figure 2. It’s stock thickness. cure this problem. primarily used to house the ends of While dadoes on larger pieces are shelves and cabinet floors, as well most easily and accurately made with as retain drawer runners. The most a hand-held router, dadoes on small common type is a through dado, which project parts, such as jewelry box runs the full width of a workpiece. For dividers, often require a table-mounted a cleaner look, a stopped dado, shown router. You can clamp a straightedge in Figure 2, may be substituted. As to your workpiece as a guide, or use the name implies, the stopped dado a shop-made “T-square jig” as shown stops short of one, or both edges. The in Figure 3 and Photos E and F. The mating piece must then be notched advantage to this jig is that it saves time

The perfect dado on the left was 23 made with a /32" router bit. The dado on the right was made with 3 a standard /4" bit.

notch by showing the location of the cut, and guarantees your cuts are square to your reference edge. The only disadvantage to this jig is that you’ll need a dedicated E F one for each router/router bit combination. If you’re routing dadoes Align the notch in the head of the Start the router in the notch and that are wider than your bit, attach two T-square jig with the layout lines, maintain the position of the router to fences to the head of the T-square and and then clamp the jig in place. the straightedge through the whole cut. make your dado in two or more passes.

16 woodcraft magazine A p r i l /M a y 2 0 0 8 FORMING SNUG GROOVES

The only difference between bit in a router table. Like dadoes, a groove and dado is grain grooves can run the full length of the orientation. While a dado runs workpiece, or be stopped. across the grain, a groove runs with A plunge router works best for the grain as shown in Figure 4. (This stopped grooves on large panels, but definition gets hazy when working for smaller pieces choose a router table. with MDF, but “grain” generally runs It’s a lot easier to take the workpiece to along a panel’s longest dimension.) the tool than clamping it in a manner Common uses for grooves are housing that won’t interfere with the router. To Fig. 4 drawer bottoms, door panels, and make the cut, butt the stock against the cabinet backs. You can cut grooves right hand stopblock and slowly lower If you need to cut narrow through with a straight bit and edge guide it onto the spinning bit. Then feed to grooves, consider slotting bits as shown in using a hand-held router, or a straight the left hand stopblock, as shown in Photo I. Because they come with a guide Photo H. Turn off the router and lift bearing, these bits can be used in a hand- it up when the bit comes to a stop. For held router. Mounted in a router table, deep grooves, make the cut in two or they can be used for all sorts of grooving more passes. chores, on edges, ends, and faces.

A Bigger Bit Bang For Your Buck

stopblock Rabbet bit sets make for a worthwhile investment. They’re especially useful in hand-held H routers. The bearings allow for accurate, repeatable cuts, and you’ll never have to fuss with To rout a stopped groove cut an edge guide. They are also on the router table, slowly lower the best way to rabbet concave the workpiece onto the spinning or convex edges (Photo C). bit. Maintain inward pressure Also, the cutting edge geometry against the fence so you won’t creates a smoother, cleaner spoil the cut. 3 1 5 3 7 1 cut than a straight bit. The /16", /4", /16", /8", /16", and /2"). Whiteside set shown here includes As a bonus, a full-sized bearing eight bearings, which allow you to enables the unit to pull double 1 make seven different rabbets ( /8", duty as a flush trim bit.

ce-PLU n S ie n

e WOODCRAFT # price

v BUYING GUIDE

o c 1. Pinnacle Premium Router Tabletop #148487 $199.99 2. Pinnacle 36" Router Table Fence #148488 $179.99 3. Rousseau Router Table Stand #148646 $119.97

4. Whiteside Rabbet Set (1/2" shank) #143223 $59.99

5. Whiteside Straight 23/32" Plywood Bit (1/2" SH) #24K19 $19.99 I 6. Whiteside Straight 31/64" Plywood Bit (1/2" SH) #24K17 $17.99

7. CMT Three-Wing Slot Cutter 1/4" H, 17/8" D #820305 $23.99 Slotting bits are great for making 8. CMT Slot Cutter Arbor w/Bearing (1/2" SH) #820307 $10.00 clean, square-bottom grooves on the router table. Above items available at Woodcraft stores, woodcraft.com or by calling (800) 225-1153.

w w w . W o o d c r a f t M a g a z i n e . c o m woodcraft magazine 17 FREE YEAR! 2 YEARS for $29.99!

go to woodcraftmagazine.com and click SUBSCRIBE -or- Complete the form below and mail in an envelope addressed to: WOODCRAFT MAGAZINE PO BOX 7020 PARKERSBURG WV 26102-9916

□ Payment Enclosed □ Bill Me Name Address City State Zip Country E-mail

Best-ever DECORATIVE FINISHES Build Better Send in now to get LUMBER RACK Done Right with a CUT LIST

Projects, Techniques and Products

Build this 2 Years for $29.99! classic SPICE BOX And learn how to… I Dovetail a case

I Divide a cabinet into compartments or go to woodcraftmagazine.com and click SUBSCRIBE I Create a cornice

By providing my e-mail address, I am indicating I’d like to receive information about my subscription and other offers from Woodcraft Magazine via e-mail.

Outside of the U.S and Canada add $30 for postage. Plus… I 4 more projects Foreign orders must be prepaid. Payment in U.S. Funds only. I Famous furniture