Making a solid connection

34_solid_connection_02Traditional joinery methods - dovetails, dowels and tenons - have been with us for a very long time and have served us well. Unfortunately, some of them require a lot of time to lay out, mill and clamp. In the current business climate, more than at any other period in recent history, time truly is money.

So it may be time to rethink tradition and take a closer look at some newer, quicker connections that can do the same job in less time.

Festool's Domino

The Domino system is a very quick way to create floating mortise and tenon joinery and do so at the high level of accuracy and reliability professional shops need. The joint is far stronger than a traditional biscuit joint, although the technology feels very familiar to anyone who uses a biscuit joiner.

34_solid_connection_01Essentially, the machine mills a round-cornered mortise in each part to be joined and factory-made floating tenons fit perfectly into these. The system has several advantages over traditional hollow chisel mortisers, not least of which is that it's portable (think job site or milling large parts where the machine moves so the wood doesn't have to). Because the machine makes both mortises with a single setup and there is no need to mill tenons, the time savings can be considerable. Festool's floating tenons are made from solid beech, which tends to expand a little (like biscuits) as it absorbs glue, making for snug fits.

Several tenon sizes are available, including a new, small version (4 x 20 mm) for drawer and small face-frame construction. Other sizes handle bigger jobs such as boards being joined to create panels and the tool's fence can also be adjusted for bevel joints (as in Lazy Susan cabinets, etc.). The beech tenons have glue expansion slots on their wide faces and a guide window on the tool makes for very fast alignment when locating the mortises. Cuts are made with a carbide-tipped spiral plunge bit that can be changed very quickly when it eventually dulls or a different size is required.

36_solid_connection_01JessEm's Zip Slot

A similar system to the Festool, the Zip Slot Mortise Mill from JessEm uses a special drill bit chucked into a standard hand drill to plow mortises. The jig is clamped in place and the drill bit is inserted into a hardened guide. The jig then moves the guide from side to side with a lever handle and this enlarges the drilled hole into a slot mortise with round ends. The guide is a bearing-guided bushing mounted on a carriage assembly. The entire carriage slides back and forth on two shafts while guiding the drill bit.

36_solid_connection_02Mortises can be cut up to 3-1/2" long and the standard model jig, No. 8100, comes with a 3/8" bearing mounted drill guide bushing and a 3/8" mortising drill bit. The standard jig (called a Mortise Mill) can be bench-mounted or clamped directly to a wooden workpiece. A smaller, pocket-sized version is available for occasional users. Zip Slot loose tenons come in 1/4" (50-pack), 3/8" (40-pack) and 1/2" (30-pack) sizes to match the included 3/8" bit or optional larger and smaller bits.

Source list

Beadlock, Rockler Cos. Inc. Tel: 800-233-9359.

CMT USA Inc. Tel: 888-268-2487

Dowelmax, O.M.S. Tool Co. Ltd. Tel: 877-986-9400.

Enlock Joining Systems

Festool USA Tel: 888-337-8600.

Hoffmann Machine Co. Inc. Tel: 866-248-0100.

JessEm Tool Co. Tel: 866-272-7492.

Kreg Tool Co. Tel: 800-447-8638.

Lamello, Colonial Saw Co. Tel: 781-585-4364.

Miller Dowel Co. Tel: 866-966-3734.

MLCS Ltd. Tel: 800-533-9298.

Route-R-Joint, Woodline USA Tel: 800-472-6950.

Three joints from Lamello

The inventor of biscuit joinery, Lamello AG has been around since the end of World War II and Colonial Saw in Kingston, Mass., has been its exclusive importer in the U.S. for more than 40 years. Lamello has come up with three innovative joinery solutions that use a standard biscuit joiner to cut slots into which three very distinct pieces of hardware are inserted. All three are designed to save time.

37_solid_connection_01Fixo biscuits (which are used primarily to create face-frame joints) are made from durable glass fiber and reinforced plastic and look like half of a traditional biscuit. The two wooden parts to be joined are butted up to each other and a traditional biscuit joiner is used to cut a biscuit slot across both parts (half the cut in each part). Then, the Fixo biscuit is tapped into the cut and it pulls the joint together as it is driven home.

37_solid_connection_02A small steel plate is used to set the plastic biscuit flush or even slightly below the surface. Lamello recommends gluing the joint, but because the Fixo biscuit acts like a clamp, there's no need to waste time clamping or waiting for the glue to cure. Grooves are cut in both workpieces simultaneously, which cuts milling time in half. A pattern of barbs and curved ridges on the biscuit enable it to pull the joint closed. Lamello suggests that the system has "a multitude of applications such as face frames for doors and furniture, plinth connections, supporting connections, extensions for boards and profiles, picture frames and fast repairing on site."

37_solid_connection_03Fixo biscuits work with existing biscuit joiners and are available in two sizes, and in 80-piece and 400-piece blister packs, or in 1,200-piece bulk packages.

The second joinery option from Lamello is called Fast. This, too, requires no new machinery or tooling and it consists of a two-part plastic biscuit. Self-cutting edges anchor one half of the connector in a biscuit slot in each of the wooden parts and the joint simply snaps together.

Fast is a great solution for parts that need to be assembled and sometimes detached, such as valance covers, mechanical access covers or decorative profiles. The Fast connectors come in blister packages of 50 pairs.

Lamello's third biscuit-shaped offering is the Clamex S-18. The key here is that the Clamex can be disassembled by means of a built-in cam lever, rather than by simple friction release (as is the case with the Fast). Made from fiberglass-reinforced plastic, the standard Clamex comes with a metal cam lever and is ideal for mitered joints. The metal provides a strong, interlocking connection for parts that require frequent installation and disassembly, so it's ideal for jobs such as trade show booths and art gallery exhibits.

A less rugged version of the Clamex, the S-11, comes with a plastic lever instead of a metal one. This is a more economical solution for joinery that will rarely be disassembled. Clamex does require that a special cutter is installed in Lamello brand biscuit joiners. Called the HW-Reversing cutter (part No. 132108), it mills an 8 mm wide groove and it runs $150. Clamex also works with other biscuit joiners by making two separate plunges/cuts to form an 8mm slot.

In simple terms, the Clamex system begins with an extra-wide slot into which half of each biscuit-shaped connector is screwed. A small hole is drilled for a Torx key in one of the surfaces and the key then turns the cam that locks the two parts together. The only visible sign of the joint is the small (6mm) hole, which can usually be placed on the inside of the joint, out of sight. The S-18 connectors are available in 18-pair blister packs and bulk packaging. A small, optional jig is available to guide the 6mm drill bit, especially on angled joints.

Miller Dowels

This is a variation on traditional dowel joinery with a couple of very innovative differences that help cut time and cost. The system uses a special stepped drill bit to drill right through the face of one furniture or cabinet part into the second part. Glue is applied and then a special matching stepped dowel is inserted and tapped until it is seated in the hole.

The shape of the dowel draws the parts together and, after the glue cures, the protruding end is simply trimmed and sanded or scraped flush. Three sizes of dowels are available, depending on the size of the parts being joined and the frequency of the dowel locations. Advantages over other joinery systems are an increased resistance to shear (as in benches, chairs, etc.); speed of installation (one hole drilled in both parts simultaneously); minimal setup and no special tooling; and the convenience of being able to work through an appearance face and have the hole automatically plugged.

Also available are the 1XSR dowel and bit that have been specially designed for commercial cabinetmakers.

Miller Dowels are available in red oak, black walnut, birch, cherry, ipé, purple heart, teak, mahogany, white oak and black locust.

Hoffmann dovetail keys

While the Hoffman system is no substitute for hand-cut hardwood dovetail joints, it nonetheless takes advantage of the bow-tie shape of dovetails to draw together face frames, door stiles and rails, moldings and other mitered and butt joints. Engineered and manufactured in Germany, the keys come in more than 35 different sizes from 1/4" to 4" long.

They are made from a high-quality polymer compound in a medium-brown color designed to blend with most finishes. Two hundred custom colors are available in the plastic keys (10,000 key minimum order for colors), as are solid hardwood versions in cherry, oak, walnut, mahogany and maple.

For European casework, solid aluminum keys come by the linear foot and can be cut to size in the woodshop. Oak keys are available in both solid wood and three-ply laminations. The solid wood is all end grain, while the stronger laminated keys can be used for higher strength applications.

Slots for the dovetail joint keys are milled by one of several machines Hoffmann offers through its Web site. They range in price from $585 to $22,980, depending on whether they're hand-held (the basic version looks like a biscuit joiner) or industrial duty floor models designed for larger cabinet shops.


Enlock is an Australian company that says it developed the plastic dovetail ties independently for joining its residential window units.

35_solid_connection_02The Enlock design has been espoused by CMT (they of the orange tools), who have developed it into a system available in the U.S. that includes, of course, an orange-colored jig. CMT's version is designed to handle T-joints and miters, using its patented E15 and E10 dovetail keys. It's ideal for face frames. The dovetail slots are milled using the jig and a standard portable router equipped with one of two differently sized bearing-guided dovetail bits. Rout half the butterfly in each part, then tap the plastic key in place.

35_solid_connection_01According to CMT, "the Enlock dovetail key expands when the cap is forced in. This widens the dovetail, producing a strong clamping force across the joint. No other dovetail system on the market produces this clamping force."


37_solid_connection_04A fairly simple joinery system offered by Woodline USA, the Route-R-Joint, is perhaps best suited to small shops and individuals than high-volume casework manufacturers. Primarily designed for drawer boxes, the jig makes traditional half-blind and through dovetails, but it also mills decorative heart-shaped dovetails.

The company claims that Route-R-Joint is easy enough to set up and be used by "amateurs, children and professional woodworkers," and some reviews affirm that opinion while others are not so sure. One notable difference between this and traditional dovetail kits is that the milling is done on a router table, so the wooden part rather than the cutter is in motion.

36_solid_connection_03Fast Joint

A more comprehensive version of the decorative dovetail system is offered by MLCS Woodworking. Called the Fast Joint, it uses a sled with a template edge and a bushing-guided straight bit chucked in the router table to mill up to 11 different variations of decorative dovetails.

Other systems

39_solid_connectionThere are several other commercially available jigs that use mechanical or wooden fasteners to create quicker joints.

Among the most popular are the Kreg Jig and pocket screw system, and the Beadlock loose tenon system, which uses a series of drilled holes to create a mortise for factory-made tenon stock.

Lesser-known options include Dowelmax, which is an aluminum block that is milled to high tolerance and acts as a self-centering guide for up to five inline wooden dowels. The advantage here is shear strength, which in basic terms is the ability of a joint 38_solid_connection_01to resist sideway pressure. Measured in pounds per square inch, the five-dowel joint scored 890; a standard mortise and tenon was 600; pocket screws were at 420 and biscuits came in at 285, according to test results conducted by the company.

This article originally appeared in the March 2010 issue.