JoineryBasics

Joinery

BASICS

popularwoodworking.com

FROM THE EDITORS OF

POPULAR WOODWORKING MAGAZINE

SPONSORED BY

Finger Joints

Dovetails

PLUS:

Text to come

Mortise-&-Tenon Joints

Learn 6 Classic Joints

ts

Includes

Plane-Storage

Project!

10 11 1 2 6 3 7 4 8 5 9 12 14 15 13 16

Accurate joinery begins with precision layout. Cumulative errors in marking or measuring can quickly add up to ill-fi tting joints. For good measure, Veritas makes a wide variety of precision marking and measuring instruments

that repeatedly score good marks among woodworking enthusiasts. And to help you complete all your cuts with equal precision, Veritas offers a fi tting selection of high-quality chisels and handsaws.

1. 05T05.01 Veritas® _{Dovetail Saw, 14 tpi $69.00}

2. 05T10.01 Veritas® _{Gent’s Saw, 20 tpi $49.00}

3. 05E14.01 Veritas® _{Journeyman’s Brass Mallet $32.50}

4. 05N10.12 Veritas® _{14° Dovetail Marker $6.50}

5. 05N10.10 Veritas® _{1:6 & 1:8 Dovetail Markers, pr. $11.50}

(only 1:8 shown)

6. 05N56.10 Veritas® _{Large Saddle Square $17.50}

7. 05N56.15 Veritas® _{Miter Saddle $14.50}

8. 05N44.02 Veritas® _{4” Sliding Bevel $46.50}

9. 05S21.12 Veritas®3_{/4” PM-V11}® _{Bench Chisel $88.00}

10. 05S26.16 Veritas® _{1” PM-V11}® _{Butt Chisel $84.00}

11. 05N43.01 Veritas® _{Square Level $24.50}

12. 05N36.01 Veritas® _{Carpenter's Gauge $24.50}

13. 05N70.10 Veritas® _{Dual Marking Gauge (with Shaft Clamp) $65.00}

14. 05T03.01 Veritas® _{1:6 Dovetail Guide with Saw $59.50}

15. 05N35.01 Veritas® _{Precision Square, Imperial $24.95}

16. 05D20.05 Veritas® _{Workshop Striking Knife $10.95}

Shipping and N.Y. sales tax extra.

Helping you make

great connections

Find us on:

1-800-683-8170

www.leevalley.com

To order these products, call or visit us online. Browse or download our 296-page

woodworking tools catalog.

CONTENTS

popularwoodworking.com ■ 1

2

Mortise

&

Tenon Basics

Learn how to cut this workhorse joint and have it last for centuries.

BY C H R I S TO P H ER S C H WA R Z

9

Shop-made

Mortise Jig

An inexpensive shop-made jig makes quick and accurate work of router-cut mortises.

BY G LEN D. H UE Y

11

Better

Finger

Joints

This nifty shop-made table saw jig helps you cut accurate machine-age fi nger joints.

BY RO BER T W. L A NG

18

Mitered

Half-lap Joinery

With a router, straight bit and a scrap of plywood, learn how to turn a weak joint into a solid and strong mitered corner.

BY G LEN D. H UE Y

20

Cut Accurate &

Clean Rabbets

Discover three good ways to cut this joint: by router, by table saw and by hand.

BY C H R I S TO P H ER S C H WA R Z

25

Dovetailed

Plane Cabinet

Learn to cut dovetails by hand as you make this handy and handsome storage cabinet.

BY C H R I S TO P H ER S C H WA R Z

PHOTOS BY AL PARRISH

9

25

EDITOR’S NOTE

S

ure, you can use metal fasteners

(nails, screws etc.) and build nice-looking projects. But if you want your work to outlast its maker, you need to learn how to cut solid joinery – it makes your projects stronger, more attractive and more durable.

In “Joinery Basics,” you get a intro-duction to some of the most useful and common joints in woodworking: rabbets, fi nger joints, mortise-and-tenons, dove-tails and more. With these must-know joints in your tool kit, you’ll be well on your way to making most any project – and making it to last.

You’ll fi nd a combination of hand- and

power-tool techniques – approaches that can be achieved with the tools and machinery found in most woodwork-ing shops – from some of our best-loved and most experienced writers: Glen D. Huey, Robert W. Lang and Christopher Schwarz.

Plus, the fi nal article, Christopher’s dovetailed plane cabinet, not only teach-es you hand-cut dovetails, but groovteach-es and dados, too. And of course, when you’re done with that project, you’ll have improved your skills and have a nice-looking storage piece for your planes.

These articles fi rst appeared in older issues of Popular Woodworking and

Wood-Solid Joinery for Several Lifetimes

11

working Magazine – the two publications

that combined to make Popular

Wood-working Magazine (PWM). In every issue

of PWM, you’ll fi nd skill-building tech-niques for hand tools and power tools, shop tricks you can put to use right away, great-looking projects with step-by-step instruction and more.

I invite you to visit us online to fi nd out more about the magazine, read the Editors’ Blog and Christopher Schwarz’s hand-tool blog, free project and tech-nique articles and more. You’ll fi nd us at popularwoodworking.com.

2 ■ JOINERY BASICS

A

lot of woodworkers spend a

lot of time, effort and money to avoid making mortise-and-tenon joints. Bis-cuits, dowels, commercial loose-tenon jigs and expensive router bits are just a few of the “work-arounds” developed this century so you don’t have to learn to make a mortise and its perfectly matched tenon.

But once you learn how straightfor-ward and simple this joint can be, you

will use it in every project. Why? Well, it is remarkably strong. A few years ago we decided to pit this venerable and traditional joint against the high-tech super-simple biscuit. So we built two cubes, one using biscuits and one with mortises and tenons. Then we dropped a 50-pound anvil on each cube. The results were eye-opening.

Both cubes were destroyed. The bis-cuit cube exploded on impact. Some of

the biscuits held on tightly to the wood, but they pulled away chunks from the mating piece as the joint failed.

The second cube survived the fi rst hit with the anvil – the joints held to-gether even though the wood split at the points of impact. A second hit with the anvil ruined the cube entirely, though most of the tenons stuck tenaciously to their mortises.

The lesson here is that biscuits are indeed tough, but when they fail, they fail catastrophically. The mortise-and-tenon joints fail, too, but they take their time, becoming loose at fi rst rather than an immediate pile of splinters.

So when you’re building for future generations and you know how to make this stout joint with minimal fuss, you won’t say “Why bother?” You’ll say “Why not?”

Choosing the Right Tools

There are so many ways to cut this joint that one big obstacle to mastering it is choosing a technique. I’ve tried many ways to cut this joint – backsaws, com-mercial table-saw tenon jigs and even the sweet $1,000 Leigh Pro Frame Mor-tise and Tenon Jig.

Each technique or jig has advan-tages in economy, speed or accuracy. The technique I’m outlining here is the one I keep coming back to year after year. It uses three tools: a hollow-chisel mortiser for the mortises, a dado stack to cut the tenons and a shoulder plane to fi ne-tune your joints. Yes, this is a little bit of an investment, but once you start using this technique, these tools

LEAD PHOTO BY AL PARRISH; STEP PHOTOS BY THE AUTHOR

Mortise & Tenon

Basics

B Y C H R I S T O P H E R S C H W A R Z

Discover a superior way to cut this superlative joint.

THE ’ANVIL’ TEST

The anvil is about to hit the cube made using #20 biscuits.

The cube made out of biscuits is de-stroyed on impact.

The mortise-and-tenon cube held to-gether after the fi rst hit.

The mortise-and-tenon cube collapsed after the second hit.

popularwoodworking.com ■ 3

4 ■ JOINERY BASICS

will become the foundation for much of your joint-making.

(For a simple and inexpensive jig to cut mortises with a router, see “Shop-made Mortise Jig” on page 9.)

■ Hollow-chisel mortisers: These

machines are nothing new, but the benchtop ones are now cheaper, more powerful and more accurate than ever. For about $240, you’ll get a good ma-chine.

Essentially, a mortiser is a marriage between a drill press and an arbor press that’s designed for metalworking. The drill press part has a spinning chuck that holds an auger bit that chews up the waste wood. The auger bit is encased in a hollow four-sided chisel that cleans up the walls of your mortise, making the auger’s round hole a square one.

The arbor press part of the machine is the gear-and-lever system that push-es the tooling into your wood. This mechanism gives you an enormous mechanical advantage compared to outfi tting your drill press with a mortis-ing attachment – an accessory I don’t recommend for all but the most oc-casional mortising jobs.

Shopping for the proper mortiser is tough. I don’t consider all the ma-chines equal. Some are weak and stall in diffi cult woods such as oak, ash and maple. Many have problems holding your work down against the machine’s table. In a review of the machines on the market in our August 2001 issue, we preferred the fast machines (3,450 rpm) instead of the 1,750-rpm slow machines (back issues are available by

calling 855-840-5118 or online at shop woodworking.com). The fast machines were almost impossible to stall. How-ever, the marketplace seems to prefer the slow machines. While none of the machines is perfect, I prefer the fast-speed Bridgewood and Shop Fox and the slow-speed Jet and Fisch machines.

■ Dado stack: A good dado stack will

serve you in many ways, but I use mine mostly for cutting tenons and rabbets. When it comes to choosing one, buy a set with 8" blades instead of 6" blades, unless you own a benchtop table saw. Stay away from the bargain sets that

cost $50 or less – I haven’t found them to be very sharp and the teeth aren’t well-ground. The expensive sets ($200 and more) are nice, but they’re probably more than you need unless you are making your living at woodworking. My favorite mid-priced set is the Freud SD208. It’s about $100 and does a fi ne job.

■ Shoulder plane: No

matter how accurately you set up your machines to cut mortises and tenons, some will need a little tuning up before assembly. And nothing trims a tenon as well as a shoul-der plane. These hand tools really are secret weapons when it comes to joints that fi t together fi rmly and are airtight. Why is that? Well, shoulder planes are designed to take a controlled shav-ing that can be as thin as .001". I can tweak a tenon to a perfect fi t with just a few passes. Trying to tweak a tenon with a chisel or sandpaper is more diffi cult. You are more likely to gouge or round over the surface of your ten-on and compromise its mechanical strength.

Buying a shoulder plane gets easier every year because there are now many quality tools on the market. Unless you build only small projects, you are going to want a plane that is at least 1" wide. Most casework tenons are 1" long, so a 1"-wide plane is perfect for trimming up the face cheeks and shoulders of the tenon.

My advice is to stay away from the newly made Stanley shoulder planes. I’ve had some sloppily made Stanleys go though my hands (vintage Stanley shoulder planes can be good, however).

Lie-Nielsen makes several

shoulder-Lever

Tape squares table

Hold-down

Table

Hollow-chisel mortisers excel at boring square holes. Here you can see the hold-down (which is usually inadequate with other machines), the table (which must be squared to the chisel before use) and the lever (which makes the machine plow through almost any job).

A shoulder plane tweaks tenons to fi t perfectly. Avoid the modern Stanley shoul-der planes (not shown). Spending a few dollars more will get you a much better tool.

popularwoodworking.com ■ 5

trimming planes worth saving your money for. The large version is a tool of great mass and presence and does the job admirably – it’s a $250 invest-ment. Lie-Nielsen also makes a rabbet-ing block plane that can be easily used as a shoulder plane; it costs $175. It’s the tool I recommend to most people because it does double-duty as a low-angle block plane.

Veritas, the tool line made by Lee Valley Tools, has a smaller shoulder

plane that’s almost 3_{⁄4" wide, quite}

com-fortable to use and reasonably priced at $189. The company also has a larger

plane that’s 11_{⁄4" wide; it costs $229.}

Other new and vintage brand names worth checking out include Shepherd Tool (made in Canada) and the British-made Clifton, Record, Preston, Spiers and Norris.

Of course, you’ll need to sharpen the tool. And that’s why we offer a free tutorial on sharpening on our web site – to fi nd it, visit popularwoodworking. com/magazineextras and scroll down to the April 2004 header.

Designing a Joint

Once you have the tools you need, you can learn about the mechanics of the joint. Study the illustration below to learn what each part of the joint is called.

The fi rst question beginners always ask is: How thick and how long should my tenons be? As far as thickness goes, the rule of thumb is that they should be one-half the thickness of your

work-piece. So a tenon on a piece of 3_⁄4"

mate-rial should be 3_{⁄8" thick.}

As for length, that depends on your project. Typical casework tenons that are 1" long will be plenty strong. For

large glass doors, make them 11_{⁄4" long.}

For small lightweight frames and doors,

stick with 3_{⁄4"- or} 5_{⁄8"-long tenons.}

What beginners often don’t ask about is the size of the edge shoul-ders on their tenons. This is a critical measurement. If you make these edge

shoulders too small, say 3_{⁄16" wide or}

so, you could run into huge problems at assembly time when building frames and doors.

Here’s why: If your tenoned piece forms one of the outside members of a frame, your mortise wall is going to

be only 3_{⁄16" wide and it’s going to be}

weak. The hydraulic pressure from the glue or the smallest amount of racking will cause the tenon to blow out this

weak mortise wall, ruining everything. It is because of this that I recommend

edge shoulders that are 3_{⁄8" wide in}

most cases. Note that your edge shoul-ders can be too big. Once they start

getting larger than 1_{⁄2", you run the}

risk of allowing the work to twist or warp in time, ruining the alignment of the parts.

Of course, if your tenoned piece is not on the edge of a frame, you can have narrow edge shoulders without any worries.

Designing the mortise is a bit sim-pler. It should be the same dimensions as your tenon with one exception:

Make the mortise 1_{⁄16" deeper than}

your tenon is long. This extra depth does two things: It gives your excess glue a place to go and it ensures your tenon won’t bottom out in the mortise, which would prevent you from getting a gap-free joint.

Beware of other tune-ups that some books and magazines suggest. One bit of common advice is to chamfer all the sharp edges of your tenons to improve the fi t. Another bit of advice is to chamfer the entry hole of the mortise. These are unnecessary if you design your joint properly.

One thing that is important, how-ever, is to mark the outside faces on all your parts. It’s important to keep these straight during machining and assembly.

Tenons First

Some traditional woodworkers tell you to make all your mortises fi rst and then

Face cheek Tenon thickness should be one-half of your stock’s thickness Edge cheek

Edge shoulder should be at least 3/8" to avoid blowing out the mortise

Face shoulder Rail

Stile Mortise

These sample mortises are useful for sizing your tenons. I usually make a new one every season or two, because they can get worn from use.

6 ■ JOINERY BASICS

make your tenons fi t that. This is good advice if you cut the joint by hand with a backsaw and a mortising chisel be-cause there is more opportunity for the mortise to be irregular in size. But you will work much faster and with much less measuring if you try it my way.

Before you cut your first tenon, you should fi re up the hollow-chisel mortiser and make a sample mortise with each size of bit you use. The three

most common sizes are 1_⁄4", 3_{⁄8" and}

1_{⁄2". These mortises should have}

per-fectly square walls and be 11_{⁄16" deep}

and 2" long. Write the month and year on each mortise and make a new set next season.

Why make these sample mortises? Well, because the tooling to make your mortises will always produce the same

width mortise, you can merely size all your tenons to one of these sample mortises as you cut them on your table saw. This will save you time down the road, as you’ll see.

With your sample mortise in hand, set up your table saw to cut your tenons. Install the dado stack blades and chip-pers on the saw’s arbor. The rule here is to install enough blades to almost cut the length of the tenon in one pass. For example, to cut a 1"-long tenon, set up enough blades and chippers to make

a 3_{⁄4"-wide cut.}

Next, position your saw’s rip fence. Measure from the left-most tooth of your dado stack to the fence and shoot for the exact length of your tenon. A 1"-long tenon should measure 1" from the left-most tooth to the fence, as shown

in the photo at left.

Get your slot miter gauge out and square the fence or head of the gauge to the bar that travels in the table saw’s slot. Attach a wooden fence to the face of the gauge (usually this involves screws through holes already drilled in the gauge). This wooden fence stabilizes your workpiece and controls tear-out as the dado stack blades exit the cut.

Set the height of the blades to just a little shy of the shoulder cut you’re after. You want to sneak up on the perfect setting by raising the arbor of the saw instead of lowering it. This does two things: One, it produces fewer waste pieces that result from overshooting your mark. And two, because of the mechanical backlash inherent in all geared systems such as your table saw, raising the arbor eliminates any poten-tial for it to slip downward because of backlash.

You are now ready to make a test cut. First put a scrap piece up against your miter gauge, turn on the saw and make a cut on the end of the board. Use fi rm downward pressure on the piece. Don’t let the end of the board touch the saw’s rip fence. Then bring the scrap piece and miter gauge back and make a second pass, this time with the scrap touching the rip fence as shown below. Flip the scrap over and repeat the

A 6" rule will help you set the length of your tenon. Once you do this a couple of times you’ll hit this measure-ment right away every time.

When making tenons with a dado stack in your table saw, the fi rst pass should remove the bulk of the material. Keep fi rm downward pressure on your work, which will give you more accurate cuts.

The second pass has the work against the fence and defi nes the face shoulder. Note there isn’t any wood between the fence and blades, so the chance of kickback is minimal. The backing board reduces the chance of tear-out at the shoulders.

Cut the edge shoulders the same way you cut the face shoulders and cheeks.

Backing board

No wood trapped between blades and fence

popularwoodworking.com ■ 7

process on the other face. Usually you aren’t supposed to use your rip fence and miter gauge in tandem, but this is an exception. This cut is safe because there isn’t any waste that could get trapped between the blades and the fence, producing a kickback.

Check your work with your dial cali-pers and see if the tenon will fi t your sample mortise. The tenon is likely going to be too thick. Raise the blades just a bit and take passes on both faces of the scrap until the tenon fi ts fi rmly and snugly into the sample mortise with only hand pressure.

If you can shake the sample mortise and the tenon falls out, you’ve overshot your mark and need to lower the arbor and try again. If the fi t is just a wee bit tight, you can always tune that up with a shoulder plane. Let your dial calipers be your guide. Sometimes you haven’t used enough downward pressure dur-ing the cut to make a consistent tenon. If something doesn’t fi t when you know it’s supposed to, try making a second pass over the dado stack and push down a little harder during the cut.

Using this setup, mill all the face

cheeks on all your tenoned pieces. When that’s complete, raise the arbor

to 3_{⁄8" and use the same routine to cut}

the edge shoulders on all your boards. Your tenons are now complete.

Use Your Tenons Like a Ruler

One of the major pains in laying out the mortise is fi guring out exactly where you should bore your hole. You end up adding weirdo measurements and subtracting the measurements of edge shoulders. If you lay out mortise loca-tions using math only, you will make a mistake someday.

Troy Sexton, one of our contribu-tors, showed me this trick one day and I’ve never done it any other way since. Say you are joining a door rail to a stile – quite a common operation. Simply lay the tenoned rail onto the edge of the stile and line up the edges of both pieces so they’re fl ush. Take a sharp pencil and – using the tenon like a ruler – mark where the tenon begins and ends on the stile. That’s it; you’ve just marked everything you need to know to make your mortise.

If you are placing a rail in the middle of a stile, there is one more step. You’ll need to mark on the stile where the edges of the rail should go. Then line up the edge of the rail with that mark and fi re away. There’s still no addition or subtraction. With all your mortises laid out, you can then get your hollow-chisel mortiser going.

A Finicky Machine

I’ve used a lot of hollow-chisel mortis-ers and fi nd them fussy to adjust. In a nutshell, here are some of the impor-tant adjustments not covered by some manuals:

■ Make sure the chisel is at a perfect

90° angle to the machine’s table. I’ve set up a dozen of these machines and only one has ever been perfect. The solution is to use masking tape to shim between the table and the machine’s base.

■ Set the proper clearance between

the auger bit and the hollow chisel that surrounds it. Some people use the thickness of a dime to set the dis-tance between the tooling. Some people measure. Either way is fi ne. If the clear-ance is too little, the machine will jam and the tooling can burn. Too much distance makes a sloppy-bottomed mortise.

■ Square the chisel to the fence. The

square holes made by the chisel should line up perfectly. If the edges aren’t per-fectly straight, your chisel isn’t square to the fence. Rotate the chisel in its bushing and make sample cuts until everything is perfect.

■ Center the chisel so it’s cutting in

the middle of your workpiece. There might be a clever trick to do this, but I’ve found that the most reliable method is to make a test cut and measure the thickness of the mortise’s two walls with a dial caliper. When they’re the same, your mortise is centered.

To locate the mortise, put the tenon across the edge of the stile where you want your mortise to go. Use a sharp pencil to mark the tenon’s location on the edge. Bingo. You’ve just laid out the mortise’s location.

Stile Rail Mortise ends here Mortise begins here

By cutting over your line slightly, you give yourself just enough forgiveness at assembly time. A little wiggle can mean a lot when you are trying to close up the gaps as you clamp up your work. Line marked on stile Mortise is cut slightly past that line 02_1406_RA_M&TBasics.indd 7 3/18/14 9:25 AM

8 ■ JOINERY BASICS

Simplify Your Mortising

As you make your mortises, here are a few tips for making things a whole lot easier.

■ I like to cut a little wide of the

pencil lines that defi ne my mortise.

Not much; just 1_{⁄32" or so. This extra}

wiggle room allows you to square up your assembly easier. It doesn’t weaken the joint much – most of its strength is in the tenon’s face cheeks.

■ As you bore your mortises, don’t

make your holes simply line up one after the other. Make a hole, skip a distance and then make another hole (see the photo below). Then come back and clean up the waste between the two holes. This will greatly reduce the chance of your chisel bending or breaking.

■ Keep your chisel and auger

lu-bricated as they heat up. Listen to the sounds your machine makes. As the auger heats up, it can start to rub the inside of the chisel wall and start to screech. Some dry lubricant or a little canning wax squirted or rubbed on the tooling will keep things working during long mortising sessions.

■ Finally, make all your mortises

with the outside face of the work against the fence. This ensures your parts will line up perfectly during assembly.

Final Tweaks

No matter how careful you have been, some of your tenons might fi t a little too tightly. This is where the shoulder

plane shines. Make a couple of passes on both face cheeks and try fi tting the joint again. Be sure to make the same number of passes on each cheek to keep the tenon centered on the rail. If your parts aren’t in the same plane when as-sembled (and they’re supposed to be), you can take passes on only one cheek to try to make corrections.

If the joint closes up on one face but not the other, you might have a sloppy shoulder. The shoulder plane can trim the fat shoulder to bring it in line with its twin on the other side of the tenon. If the tenon still won’t seat tightly, try chiseling out some meat at the corner where the edge shoulder meets the face cheek – but don’t trim the outside edge of the edge shoulder itself.

Finally, get a sharp chisel and clean out any gunk at the bottom of the mor-tise. Keep at it – a tight joint is worth the extra effort.

Assembly

You really don’t want any glue squeeze-out when you assemble your mortise-and-tenon joints. The trick to this is learning where to put the glue and how much to use. I run a thick bead of glue at the top of each mortise wall and then paint the inside of the mortise wall with glue using a little scrap piece. I try to leave the glue a little thick at the top of the mortise wall. Then, when the tenon is inserted, this paints the tenon with glue but drives the excess to the bottom of the mortise.

When clamping any frame – re-gardless of the joinery you used – you don’t want to use too much pressure or you will distort the frame. Tighten the clamps until the joints close and no more. You also want to alternate your clamps over and under the assembly to keep the frame fl at – no matter how fancy your clamps are.

Once you do this a couple of times, I think you’ll fi nd a whole new level of woodworking open to you. Web frames for dressers (or Chippendale secretar-ies) will seem like no problem. Morris chairs with 112 mortises will be within your reach. And your furniture is more likely to stand the test of time – and

maybe even the occasional anvil. PWM

Christopher is a regular contributor to Popular Wood-working Magazine and the publisher at Lost Art Press

(lostartpress.com).

Shoulder planes are capable of extraordinarily precise work. Just try to set your table saw to remove .001". It’s not possible. For a shoulder plane, it’s simple.

A thick bead of glue at the top of the mortise wall makes the joint strong without squeezing out a lot of glue. Use a small piece of scrap to paint the mortise wall before inserting the tenon.

Scrap

popularwoodworking.com ■ 9

R

eproduction furniture is my

main focus in woodworking, so I think one of the most important construction joints is a mortise-and-tenon joint – and not simply the use of a stub tenon, but a full-blown tenon that ranges between

1" and 11_{⁄4" in length depending on the}

project and if there’s adequate depth in the material.

Due to the number of these joints I make, I have a dedicated mortising ma-chine. But if you need to create a mortise and tenon and you don’t have a dedicat-ed machine to use, whip up this simple jig from a few scraps of wood and use a plunge router, a properly sized guide bushing and an upcut-spiral router bit. (You can use a straight router bit, but an upcut bit lifts waste material out of the mortise, so it makes a cleaner cut.)

Make a Guide Bushing Slot

The fi rst step in building this jig is to

create a slot in a piece of 1_{⁄2" plywood}

to guide the bit’s location as you plunge into the workpiece – plywood’s stability makes it a better choice. Don’t create a slot that matches the router bit size; you need to match the slot to the guide bushing’s outside diameter.

Select a bushing with a diameter that’s larger than the router bit. For

standard 3_{⁄4" material, I use a} 3_⁄4

"-out-side-diameter bushing for two reasons; this diameter is a standard drill bit size and the slot matches the thickness of the stock with which I’m working.

When working with 3_{⁄4" material, select}

a plywood scrap that’s about 33_{⁄4" wide}

and at least 12" long, then establish a

centerline. Chuck a 3_{⁄4" drill bit into a}

drill press.

To determine the length needed for your specifi c mortise when using

LEAD PHOTO BY AL PARRISH; STEP PHOTOS BY THE AUTHOR

Shop-made Mortise Jig

B Y G L E N D . H U E Y

You don’t need fancy tools or a special machine to create a traditional joint.

A mortise-and-tenon joint is one of the strongest, most useful joints in woodworking. With scraps from the waste bin, you can create a jig that does the job and is simple to use.

12" 3_{⁄4" guide bushing} X+1⁄2" X 33⁄4" 1_{⁄4" router bit} MORTISE JIG

a 3_{⁄4"-outside-diameter bushing and a}

1_{⁄4" router bit, add} 1_{⁄2" to the fi nished}

length of your required mortise. The additional opening allows for the dif-ferences between the router bit and the guide bushing.

Next, lay out the fi nal measurements on the centerline of the plywood. Posi-tion a fence so the center point of the drill bit aligns with the centerline on your plywood. Drill the two end holes fi rst, making sure to position the

10 ■ JOINERY BASICS

side diameter of the bit’s cut with the outside location of the layout.

Once the ends are established, re-move the additional waste with your drill bit while keeping the workpiece tight to the fence. When fi nished, the slot has smooth sides. (You can touch up the sides with a rasp or fi le if you need to.)

Two Side Pieces

Complete the Jig

For step two, position two additional scrap pieces on either face of the mate-rial to be mortised while holding one end of each piece fl ush with the end of the workpiece. Next, clamp the three pieces into a bench vise. These scraps or side pieces should be nearly as long as the slotted top piece of the jig.

The key to building this jig straight and centered is in the fi nal step. Lay out the mortise on your workpiece; I fi nd it best to do the layout work using the overall length of the slot, keeping in mind that my fi nished mortise will be

1_{⁄2" shorter. Position the plywood piece}

on the three pieces in your vise, align the slot with the layout lines at the top and bottom, and with the edges of the workpiece looking side to side. Once you’ve got the slotted piece properly positioned, add a couple clamps to hold everything in place.

Attach the slotted top to the two

side pieces with #8 x 11_{⁄4" screws – two}

screws per side. Counterbore the holes for the screws. This is not the time to split or crack the side pieces. Pull the

assembly from your vise and remove the workpiece. The fi t should be snug so it will take some muscle to remove the workpiece from the jig.

Plunge a Mortise

Set up your router with the guide

bush-ing and a 21_{⁄2"-long router bit. You’re}

now ready to work. A bit this long allows

you to plunge a mortise just over 11_{⁄4" in}

depth into the workpiece after passing

the jig’s 1_{⁄2"-plywood top.}

Match the jig’s opening to the layout lines on your workpiece and clamp the two together in a vise or with oth-er clamps. Zoth-ero out the routoth-er bit by plunging down (with the power off and the router unplugged) until the bit touches the workpiece, then lock the plunge mechanism. Use the router’s depth stop to set the plunge depth.

The base of the router sits securely on top of the jig and the bushing, which fi ts snugly in the slot, adds to the overall

stability. To create the mortise, release the locked plunge mechanism and pull the router setup tight to one of the ends. With the bit standing above the work-piece, start the router and hold tightly against the slot’s end as you plunge to full depth.

Allow the router bit to retract from the hole, slide the router to the oppo-site end and plunge a second hole. To remove the material for the balance of the mortise, repeat the plunge action, each time positioning the router setup over an unexcavated area.

Once most of the waste is removed and no section remains that bridges the two sides of your mortise, return to one end of the slot, plunge to the bottom of the mortise and make a pass along the entire length to clean and straighten the sides. Make it a point to travel the length while holding the bushing fi rm to one side, then make a return pass holding tight to the opposite side. The result might be slightly wider than the

1_{⁄4" router bit, but because you make the}

mortise section of the joint fi rst then match the tenon, this won’t be an issue.

This jig is easy to build and can be used repeatedly with consistent results. The only decision you’ll need to make is should you round your tenons to match the mortise, square the mortise ends to match the tenons or create tenons with wiggle room – not snug to the mortise’s rounded ends. I always opt

for wiggle room. PWM

Glen is the former managing editor of Popular Wood-working Magazine; he is now the editor at American

Woodworker.

The overall length of your mortise is deter-mined by the slot cut into the jig’s top. Make sure to compensate for differences between the bushing and router bit.

Once the plunging cuts are completed, fi nish the mortise with a pass along both faces of the slot. This last step smooths and cleans the slot. Once the parts of the jig

are positioned around the piece to be mortised, add screws through the top to complete the jig.

popularwoodworking.com ■ 11

M

ost woodworking joints

can be traced back in time for centuries. Ancient Egyptians excelled at dovetails and the Romans relied on mortises and tenons. Joinery was all handwork until the Industrial Revolution mechanized most processes in the middle of the 19th century. Mortisers, table saws, tenoners and dovetailing machines were all in common use well before 1900.

In addition to new ways to make old joints, machinery and tooling were developed to create joints that weren’t common at the time, but became popu-lar because they could be made quickly. The fi nger joint, also called a box joint, is an example of this development.

Before the machine era, this joint was used only to form a wooden hinge. When first developed, and until re-cently, it was strictly utilitarian, used mainly to make strong shipping boxes and crates. With our current infatua-tion for visible and decorative joinery, the fi nger joint has moved from utility to visibility.

The effort to cut a fi nger joint en-tirely with hand tools is at least equal to the effort to hand cut dovetails. In

LEAD PHOTO BY AL PARRISH; STEP PHOTOS BY THE AUTHOR; ILLUSTRATION BY MATT BANTLY

Better Finger Joints

B Y R O B E R T W. L A N G

The dovetail’s machine-age cousin is fussy to cut and assemble;

we’ve fi xed both those faults.

A shop-built router jig can make large, accurate fi nger joints. The solution for mak-ing a better jig proved to be fi ndmak-ing a better duct tape.

12 ■ JOINERY BASICS

many ways it takes more effort, and the return for the effort is dubious. It is a more demanding joint to make, and it lacks the inherent mechanical advantage and aesthetic appeal of the dovetail. But it is signifi cantly easier and faster to make fi nger joints by ma-chine, if one is willing to work precisely to set up the tools.

For example, a jig we used to build a blanket chest (you’ll fi nd that proj-ect free online at bit.ly/1k7vvnN) was

intended to have slots and fi ngers 5_⁄8"

wide. When completed, the overall

width of the jig was 1_{⁄16" bigger than}

planned. That translates to an error in each component of .0025", about half the thickness of the average human hair. Because the parts are all the same size, the joints produced fi t together nicely, and if I hadn’t told you about the variation, you wouldn’t notice it in the fi nished piece.

If you’re trying to cut fi nger joints with a fi xed-width cutter such as a dado stack or router bit, that half-a-hair is about the outer limit of tolerance. If you can’t set up, measure and adjust in those teeny increments, you’ll be dependent on luck alone to make a nice fi nger joint. But working to that degree isn’t as hard as you might think.

A Rout of Passage

Making fi nger joints is a good oppor-tunity to develop skills. Even if you

abandon fi nger joints after one or two tries, the exercise will expand your woodworking vocabulary. You may decide to move on to more attractive joinery, or you may decide that this is a worthy method for much of your work. In either case, the effort will make you a better woodworker. The lessons learned in finger joints will serve well in other areas.

Finger joints are very strong. The amount of interlocking surface area makes a corner with a large area of

long-grain to long-long-grain glue surface and good mechanical strength. The only weak area is the way the joint resembles a hinge. A sharp impact directly on the corner can cause the joint to unfold or come apart. Except for that disastrous scenario it’s as strong as a joint can be, and a good choice for small boxes and drawers.

The type of wood used will make a difference in how forgiving the joint is to put together. Softer woods, such as pine or poplar, will compress when

A good fi t on a fi nger joint can be assembled with hand pressure only. If you need to beat on it or clamp it to get it to close, it is too tight.

Clamp the work securely to the miter gauge and make certain the cut is within the waste area.

Confi dence in cutting is the key to a success-ful joint, whether it is cut by eye or by jig. An attachment to the miter gauge shows the exact location of the cut, allowing you to make ir-regularly spaced joints.

popularwoodworking.com ■ 13

assembled. White oak or maple aren’t as cooperative, and may require more force to assemble, and more fi nesse to make the joint. This is a place where the science of the machinist and the art of the woodworker converge. The tolerances are close, but the joint should be made so that it can be assembled without resorting to clamps or ham-mer persuasion.

The location of the sweet spot for fi tting will also vary with the width of the joint or the number of fi ngers. It’s a matter of compounding errors, and like compounding interest, a number that seems insignifi cant can grow large enough to defeat you. A handful of fi n-ger joints for a drawer is fairly easy. A fi nger joint the size of those used on the blanket chest (especially in a hard, unforgiving wood) is pushing the limits, but not beyond possibility for the careful craftsman.

Consistency and repeatability is the key to fi nger joints. If you can cut accurately (and stay on the right side of the line) you can line up each cut individually. Attaching an L-shaped backer to the table saw’s miter gauge shows the exact location of the cut, and this can be used quite effectively to make precise cuts on the table saw. If the spacing of the fi ngers varies as shown, and you’re only making a few joints, this is a faster method than mak-ing a dedicated jig.

Regularly sized and spaced fi ngers shout for a jig. It’s fussy work, but repeti-tious. The secret is to use a method that builds consistency into the process. If the work is small enough to safely travel vertically over the saw blade, the jig pictured at right is an old standby that works well.

Time-tested Method

This is the classic method of producing a fi nger joint with a jig that attaches to the table saw miter gauge, and it works very well for small pieces. It’s reason-able to run a drawer side vertically over the table saw, but longer or wider work becomes unwieldy. If you’re uneasy about holding the work on the table saw, try the router jig on the next page.

Because the table saw jig requires the

Jig construction for the table saw method starts with cutting a notch in the plywood backer that attaches to the miter gauge.

One half of the joint is cut against the guide block, forming a notch. The other half is held away by the spacer, cutting out the corner. The hardwood guide block must match the width of the slot exactly. It’s right when you can feel some resistance as you press it into the slot by hand.

Both pieces are cut at the same time. After the fi rst cut, the pieces are placed with the notches over the guide block.

An extra piece of hardwood is used to set the distance between the blade and the other block. Make it long enough to be held against the blade front and back.

As the cuts continue, each cut registers the next cut, and if the setup is correct, the work proceeds quickly.

TABLE SAW FINGER JOINTS

14 ■ JOINERY BASICS

saw to be set up with a dado head, cut all the parts you need before changing over to the stack dado set. You should prepare the parts for the jig, the parts you intend to join, and several extra pieces of stock for making test cuts.

You’ll need a piece of plywood, at

least 1_{⁄2" thick and about 6" x 12". In}

addition, you’ll need a piece of hard-wood the exact thickness of the width of the cut and about 12" long. I rip the hardwood a little thicker than neces-sary, then use a handplane to sneak up on a good fi t in the slot. It doesn’t hurt to have an extra piece on hand in case you go too far with the plane.

Simple Concept – Precise

Execution

After installing the stack dado head

(we used 1_{⁄4", but the fingers can be}

any width) make certain the head of the miter gauge is square to the blade and adjust the height of the blade to the thickness of the parts to be joined. Hold the plywood vertically against the miter gauge and make a cut near the end. The exact location isn’t critical,

but leave at least 3_{⁄4" to 1" beyond the}

cut. From here on, you need to be as precise as you can be.

Reduce the thickness of the hard-wood guide block until you can press it into the slot in the plywood. You need only worry about the thickness, not the width, as long as the width is less than the height of the slot. A set of cali-pers will help in letting you know how close you are. If you measure your plane shaving, you will be able to predict the size as you work, and you should check the fit of the actual piece in the slot frequently.

When the piece fits, cut a couple inches off one end and glue it in the slot. I use cyanoacrylate (CA) so I don’t have to wait too long for the glue to dry, but any wood glue will work.

After letting the glue dry, place the longer piece of hardwood against the edge of the dado stack. Slide the miter gauge into position, then move the ply-wood laterally until the two hardply-wood sticks are touching along their lengths. Don’t throw the longer piece away; you’ll need it again in a few minutes.

A NEW WAY TO ROUT FINGER JOINTS

W

hen we began to plan this article, the emphasis on fi nger joints was a given, but the specifi c techniques weren’t. We knew we would feature the table saw and dado method for small parts, but we weren’t comfortable milling larger pieces that way. Our fi rst thought for large case pieces was to use a commercially made router jig. That is indeed a workable solution, and many well-made jigs are on the market.

But it didn’t seem right to offer no other alternative than sending read-ers out to make an expensive pur-chase for a joint they will likely make only on an occasional basis.

Being of frugal stock, I decided there must be another way. The key to fi nger joints is equal sizes, and I realized that by making fi ngers and spacers from stock ripped at the same time, I should be able to put

together a jig that would perform as well as anything available on the market. In less than an hour I had a working prototype of the jig we used.

Rip the Strips

We were after joints with 5_⁄8"-wide

fi ngers and slots, so I began by rip-ping 1_{⁄2"-thick Baltic-birch plywood to}

that dimension. The reason for using the plywood was to eliminate wood movement from the equation. I made a couple test cuts and measured the results with calipers to get as close as possible to the proper size.

Ripping carefully from a wide piece of plywood stock yielded enough material to cut the 51_⁄2"-long

fi ngers and the 23_{⁄4"-long spacers.}

After cutting these parts to length, I attached the parts to a 23_⁄4"-wide, 3_⁄4"

-thick plywood backing strip with yel-low glue and 23-gauge pins. I laid a few beads of glue on the strip, started

FINGER JOINT JIG

3_{⁄4"-thick backing strip}

Backing board reduces tear-out Stop

23⁄4"-long spacers 51⁄2"-long fi ngers

Fingers and spacers are all the same width, ensuring con-sistency. After the jig is assembled, the joints are cut with a router using a top-mounted bearing bit.

popularwoodworking.com ■ 15

with a long piece, and made sure the fi rst piece was squarely placed then butted the parts against one another one at a time and nailed them down. A longer 23_{⁄4"-wide piece was added}

below to stiffen the jig and provide a place for clamping the jig to the bench.

A larger piece of plywood was glued and screwed at a right angle to the backing strip. I placed the screws below the fi ngers so that I wouldn’t cut into them with the router later on. This piece prevents the wood from tearing out on the back of the cuts, and provides a way to attach the work to the jig. One edge of the backer piece is aligned with the edge of the fi rst fi nger, and a small piece of scrap is attached to the edge to act as a stop.

Both panels of the joint are cut at once. The edge of one piece is placed against the stop with the show side out. The edge of the other is aligned with the opposite side of the fi rst fi nger, offsetting the joint one fi nger’s width.

Making the fi ngers of the jig the same size as the fi nished parts simpli-fi ed construction and reduced the chances of making an error in cal-culating the difference between the diameter of a router bit and a template guide. A 1_{⁄2"-diameter fl ush-trimming bit}

with a bearing mounted above the cut-ter would trim the work exactly to the edges of the jig.

Or so I thought. The pieces from my fi rst test cut went together too easily, leaving visible gaps at each joint. My quest for perfection was almost foiled by router and router-bit behavior. My measurements showed the bit and bearing to be the same diameter, and the width of the fi ngers and spacers to be equal. But the act of making the cuts produced slots a few thousandths of an inch wider than the fi ngers.

This wasn’t entirely unexpected. To get a bit with a 1_{⁄2"-diameter cutter}

and bearing, I had to use one with a

1_{⁄4"-diameter shank. Even with a pretty}

good router and a quality bit, enough runout existed to increase the width of the slots by a few thousandths of an inch. This error was consistent, and rather than seek perfection where it didn’t exist, I looked for an easy way to make an adjustment to the jig.

The fi ngers of the joints were undersized, so either the long fi ngers of the jig needed to be wider, or the spacers in between narrower. Either solution would mean taking the jig apart and starting over. The fi rst step was to see how much change was needed, and answering that question led to a fast and simple solution.

I put blue masking tape on the sides of each fi nger. My guess was the thickness of the tape would move the router bit enough to obtain a good fi t.

My instincts were good, but the bear-ing on the router bit destroyed the tape while cutting the fi rst test joint.

I headed down the street to the local hardware store in search of something thin, sticky and durable. The solution proved to be aluminum duct-sealing tape. This is not to be confused with common duct tape. Duct-sealing tape is much better.

This tape is a thin metal foil with a very sticky back. I cut small pieces off the roll with an X-Acto knife, peeled off the backing paper and placed a piece on the side of each fi nger. I pressed the handle of the knife over the tape to press it fi rmly in place. It held up well during routing, and the $9 roll of tape is likely a lifetime supply of an excellent shim material.

Using a router bit with a smaller diameter than the fi ngers is an advan-tage. As we experimented with differ-ent techniques, we found we achieved the best results by pushing the spin-ning bit straight in between the fi ngers to start each cut. This removed most of the waste without putting pressure on the fi ngers of the jig.

We then made two more passes, holding the bearing against each fi nger to make a light, clean cut. Both sides were cut by pushing the router into the jig instead of coming in on the left side and out on the right. This reduces tear-out that otherwise might occur as

The fi rst workpiece is placed with the end tight against the bottom of the fi ngers, and the left end against the stop.

The second piece is placed over the fi rst, with the left side fl ush against the outer edge of the fi rst fi nger on the jig.

Dial calipers will help you zero in on the exact measurement you need.

Second workpiece fl ush to the edge of the jig

Stop

16 ■ JOINERY BASICS

the router bit exits the work on the right-hand side of the slot. This may seem like extra work, but the fi nal two cleanup passes take little time and produce cleaner edges.

With the large pieces of the blanket chest, it was easier to place the backing piece of the jig fl at on the bench, clamp the work to the jig, then turn the jig and the work together to a vertical position before clamping the jig to the bench and routing the joints.

This was far easier than trying to hold the workpieces upright while aligning and clamping them to the jig. Fitting the end of the workpieces tight against the bottom of the fi ngers is critical to obtaining a good joint.

Ideally, the width of the work should be some multiple of the fi nger width. This leaves the joint with a whole fi nger or whole space at either side. The stop can be positioned to leave a partial fi nger at each end, as long as the second piece is offset by

the width of a fi nger.

I considered buying some alumi-num bar stock to make a permanent version of this jig – one that would last forever and be incredibly adjust-able for any size of box or fi nger confi guration. Luckily, I was talked out of that notion by a co-worker who pointed out that it was so fast and simple to put together this jig that it made more sense just to build a new iteration whenever the need occurred. — RL

Assembly is simply a matter of gluing and nailing the fi ngers and spac-ers to a plywood strip. After making sure the fi rst fi nger is square, butt one piece against another and nail in place.

Aluminum duct-sealing tape closes the gap caused by router and bit runout, and holds up well in use.

Clamp the plywood to the miter gauge and secure it with a couple pan head screws. If all went well, you’ll be in the right position. If not, the fl at areas un-der the screw heads will let you move the plywood side to side for a fi ne ad-justment.

First Cut – Testing, Testing

Both halves of a joint are cut at the same time. One piece is held against the hardwood protruding from the plywood, and the other piece is offset by the width of the slot. The extra piece of hardwood is used as a spacer to align the parts for the fi rst cut.

Clamping the two pieces together,

A NEW WAY TO ROUT FINGER JOINTS (CONTINUED)

and to the plywood attached to the miter gauge, allows you to make the fi rst cut safely. You won’t have to worry about the pieces slipping, and you can concentrate on moving the miter gauge smoothly forward with your hands away from the dado stack.

After making the fi rst cut, set the spacer aside. Each succeeding cut is made by placing the notch just made over the hardwood, as seen in the pho-tos on the facing page. The spacer will keep the work from slipping sideways, so you don’t need to use a clamp after the fi rst cut. You can pause after the fi rst few passes to see if the fi ngers and slots fi t together, but it goes fast enough that

I prefer to cut the entire width of the joint before making a test fi t.

There are three possible outcomes. In the best case, the two parts of the joint will come together with hand pressure only and have no visible gaps. If the joint won’t go together at all, the fi ngers are wider than the slots. To cor-rect this, loosen the screws holding the plywood to the miter gauge, and move the plywood so that the hard-wood guide is closer to the blade.

If the fi t is sloppy, the fi ngers are too small, and the plywood needs to be moved in the opposite direction. When adjusting either way, use the extra hardwood spacer as an aid. It’s

popularwoodworking.com ■ 17

The fi nal step is to trim the surfaces of the joint fl ush. Close cutting will mean little trimming. This may look crazy, but it works. Thin cyanoacrylate glue will wick into the joint after it is

clamped together and hold as well as any other method of gluing.

easy for something to slip a little as you hold things in position and tighten the screws. When you’re happy with the fi t, making the joints goes quickly, and as long as the parts are the same width, there aren’t many things that can go wrong. A similar jig can also be used on a router table.

Better Way for Bigger Boxes

On larger work, a better approach is to build a jig for moving the tool across the work. The fi rst choice for this is the router instead of the table saw. Our solution is the shop-made jig on the two previous pages. Equal-width material for the fi ngers and spacers is the key element to this jig. It is quick to assemble, adaptable to any practical width, and with a bit of tweaking is incredibly accurate.

Though fi nger joints look complex, the idea is that the cuts be made effi -ciently. With many joints, the bulk of your time will be in tweaking the fi t after machining. The opposite is true of fi nger joints; take your time getting set up to make the cuts so they will fi t nicely directly from the machine.

Make extra pieces to test your jig, your setup and your technique. I start with two pieces of stock, and if the fi rst

test isn’t quite where I want it, I trim a couple inches or so off the ends and try again. This leaves enough to have assembled joints to see if I’m really making progress, but doesn’t waste material unnecessarily.

A Crazy (Glue) Solution

The downside to the fi nger joint is that it takes some time to apply glue during assembly. Water-based glues will swell

the fi ngers and that can keep the joint from going together. Or the glue can begin to dry on one end before you have fi nished spreading the glue.

One solution is to partially assem-ble the joint, and apply the glue with a brush. If it’s a large assembly, use a slow-setting glue such as liquid hide glue or polyurethane glue, and clamp the corners one at a time.

An alternative we found is to as-semble and clamp the joint without glue. Thin CA glue is then applied along the outer intersections of the joint and allowed to wick into the joints. Set one side of the joint horizontally, apply the glue and wait about fi ve minutes before turning the work and gluing the op-posite side.

With this technique the glue won’t dry instantly, but if left for a few hours it will become as strong as a convention-ally glued joint.

We tried this method with some other glues, including thin PVAs in-tended for fi xing loose joints in chairs. The “Chair Doctor” produced a strong joint, but sealed the end grain enough that it showed when the joint was fi n-ished. The CA glue left no visible traces after the completed joint was trimmed

with a block plane. PWM

Robert is executive editor of Popular Woodworking Magazine.

18 ■ JOINERY BASICS

O

ne of the strongest joints in

woodworking is a properly fi t mortise-and-tenon and the opposite in strength is a simple butt joint. For years I built base frames with mortise-and-tenon joints at the rear and mitered corners at the front. The miters were joined with biscuits. The rear joints were much stronger, so I wanted to add strength to those mitered front corners, but how? Not with mechanical fasteners; screws were out. I needed something quick to create and when assembled, I wanted the joint to retain a mitered look. The answer was a mitered half-lap joint. With a half-lap, there is plenty of fl at-grain glue surface, and that increases the holding power, big time.

Tools for the Task

Quick means simple in my book, so if a bunch of tools are needed, forget it. Goodbye, handtools. The process I came up with works with a router, a straight bit and a piece of plywood that’s a couple inches wider than your work-piece and long enough so it’s easy to add clamps. Trim one end of the plywood to a 45º angle to make things easier.

With this technique, the router sit s on top of the workpiece and kisses the fence on the fi nal pass. It’s best to have a straight edge on your router’s base plate, or make sure you have accurately adjusted a round base plate so the bit is centered. An off-center base plate, depending on how you hold the router each time it’s picked up, allows the possibility that you’ll miss the layout line as you plow out the waste.

The straight bit can be any straight bit that you have in your arsenal. You’re only going to use the end of the bit, so

even a top-mount bearing-guided bit works. A smaller-diameter bit is a bit easier to use, but because the cut is most

often 3_{⁄8" in depth (half the thickness),}

a larger diameter bit is no problem.

Keep the Players Straight

To begin, cut your pieces to their fi

n-ished length. For a base frame, miter the ends of the front rail at 45º – the adjoining returns are left square.

Chuck a straight bit into the router and set the depth of cut very shallow.

Grab a couple pieces of scrap and position one on top of the other leaving a few inches to the right of the top piece,

LEAD PHOTO BY AL PARRISH; STEP PHOTOS BY THE AUTHOR

Mitered Half-lap Joinery

B Y G L E N D . H U E Y

With a router, straight bit and plywood scrap, turn a weak joint

into a superhero of strength.

Mitered joints are a common woodworking joint. Most are splined or joined with biscuits and lack real strength. With a quick setup that uses your router, you can master the mitered half-lap. When assembled, this joint rivals a tightly fi t mortise-and-tenon.

popularwoodworking.com ■ 19

as shown above right. This makeshift fence allows you to fi nd the exact offset from the edge of your base plate to the edge of the straight bit. Make one pass with the base riding along the fence then measure the distance from the fence to the dado. This is the offset measure-ment. Remember it.

Layout is key. Form the half-lap on the wrong face of the pieces and you’ll lose the mitered look, so mark the faces to remove the bottom half of the miter-cut end and the upper half of the square-cut ends.

Draw an angled line (45º) on the squared ends beginning at the corner then square a line across the mitered ends beginning at the edge of the cut. Draw a second line, offset by the ear-lier measurement (the one I told you to remember), that’s parallel to the fi rst lines.

Position your plywood fence at the second layout line with the angled end toward the mitered end of your work-piece. Hold the fence fl ush with the bot-tom edge of the workpiece then clamp the fence in place.

After you adjust the bit to remove half the thickness of your workpiece, nibble away the waste beginning at the end of the workpiece and working toward the plywood fence.

On your last pass, hold the router

base tight to the plywood. At the end of the cut, the router base plate hangs mostly off the edge of the workpiece, so maintain pressure to keep the plate tight on the workpiece.

To clean the bottom waste from the miter-cut piece, align your fence with the square offset line, hold the bottom edge fl ush with the workpiece then nib-ble away the waste. Work slowly from the point to the fence.

With the waste material removed from both workpieces, your joint will slip together with both shoulders tight. The increased glue surface adds strength to the joint and when viewed from the top, the joint appears to be mitered. This is a great technique for base frames, picture frames or any-where else your woodworking calls

for a mitered corner. PWM

Glen is the former managing editor of Popular Wood-working Magazine, and now the editor of American

Woodworker.

The key to this technique is accuracy. Find the precise offset measure-ment through a sample cut to ensure you’ll have a perfect fi t.

If you’re comfortable with your router abilities, remove waste using a climb-cut, as well as in the traditional left-to-right manner.

Whether it’s an angled line on a square end or a square line on an angled end, the offset line is king. Plus it’s where to position your fence.

With accurate layout and routing, the completed portion is perfectly cut to accept its half-lap mate.

It’s easy to allow the router to tip into the cut portion as you work. Keep downward pres-sure on the base plate with one hand while steering the router with other.

20 ■ JOINERY BASICS

W

hen I was taught to cut

rab-bets in my fi rst woodworking class, we made them with two cuts on the table saw. You’ve probably seen this tech-nique in books and magazines before. For the fi rst cut, the work is fl at on the table. For the second cut, you stand the work on edge and press it against the fence as you move the work over the blade. The waste falls away and your joint is complete.

I’ve always struggled with this tech-nique. It never seemed to produce a perfect rabbet every time. The tech-nique does have its strengths: Most woodworkers have a table saw and a rip blade to make the cut; when it works, it does produce a nice smooth joint. But after years of doing it this way, I con-cluded that this technique has several serious weaknesses:

■ Standing the work on edge requires

a tall rip fence, perfect balance on your part and a zero-clearance insert in your saw’s throat plate.

■ The joint is time-consuming

be-cause it almost always requires two saw setups and several test pieces to get it just right.

■ You have to move the saw’s guard

out of the way for the second cut, no matter which brand of guard you have on your saw.

So we decided to look for a better way to make rabbets. We found two good methods. The fi rst uses two scraps and a dado stack. The second is an improved two-step process that’s virtually fool-proof. But before we get to that, a quick

LEAD PHOTO BY AL PARRISH; STEP PHOTOS BY THE AUTHOR

Cut Accurate &

Clean Rabbets

B Y C H R I S T O P H E R S C H W A R Z

Discover three methods: by router, by table saw and with hand tools.