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A Strong Argument for Loose Tenons
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The most popular furniture joint just got a whole lot easier. The new Beadlock™ system is a dream to work with and delivers perfect mortise and tenon joints every time. Aside from their patented jig, the only tool required is a drill — no more chisels, mortising machines, table saw jigs or endless shaving to get that exquisitely cut joint. All you have to do is clamp the jig in place and drill a few holes, then insert a length of the company’s pre-milled tenon stock. It truly is that easy.

Why a Loose Tenon?
I shop tested the Beadlock™ system and discovered a number of surprises — not the least of which was that the system also makes a wonderful doweling jig for standard 1/2" and 3/8" dowel stock. But its true value lies with its designed function: creating mortises for the company’s premanufactured hardwood loose tenons. All loose tenons floats in the space formed by two opposing mortises, but beadLOCK’s version has a number of advantages over a standard squared tenon. The multiple flutes are, in effect, the equivalent of joining either three 1/2" dowels or five 3/8" dowels together. The innovative shape offers a large amount of side-grain gluing surface, for an extremely strong joint. The design also prevents the joint from wiggling from side to side and working itself loose over the years.

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Once the beadLOCK is clamped in place it’s a simple matter to switch from position A to position B and drill the holes required for your tenon stock.
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Position A holes are shown in blue;
Position B holes are shown in red.
Some Workshop Observations

Back in my shop, I took a long, hard look at the beadLOCK jig and its matching moldings. The kit I tested was the top of the line version, which included everything necessary to construct joints with both 3/8" and 1/2" thick tenon stock. The first thing I discovered was both the plate and the two guide blocks were made in the USA of hardened steel, so they’re as durable as they need to be for years of regular use. Block machining was top quality, and the set screws were big enough to grip and use.

The matching hardwood stock I received in my kit tested at 6 percent moisture, which is just about as dry as it can be in this part of the country. That’s good — if the molding shrinks too much after assembly you’ll end up with a loose fitting joint. The birch molding lay straight as a die on my bench, and came packed in 12" lengths. The individual 1/2" and 3/8" kits each contain two feet of molding.

One nice thing I discovered was the length of the tenon is only limited by the length of your drill bit. The beadLOCK jig itself places no limits on length. That means that, for small assemblies, you can use perhaps an inch of molding, while in large joints like tables or desks, a three or four inch long tenon can be used.

About the only thing I didn’t like about this system is that the shim package, designed to offset the jig for stock that’s thicker than 3/4", was made of plastic. I would have preferred steel.

Overall Impressions

I made several mortise and tenon joints in various species and thicknesses of stock, all without any mishap. Each of the joints I constructed fit like a glove. I followed the manufacturer’s instructions (beadLOCK is made by the Journeyman Tool Company of Horicon, Wisconsin) and trimmed the tenon stock 1/8" shorter than the combined depth of the two mortises: doing this, all my joints closed perfectly under clamping pressure. It didn’t take long to discover that such tight joinery doesn’t require a whole lot of extra glue. My suggestion is to mask the joint to collect the excess squeeze-out.

Once the beadLOCK is clamped in place it’s a simple matter to switch from position A to position B and drill the holes required for your tenon stock.The system requires that you clamp the jig to the work, then lock the guide block in place and drill three holes for the 3/8" stock (or just two for the 1/2" molding). Then you loosen the jig, slide the block to the right and lock it down before drilling the last two holes. I found the holes come out more evenly if you drill the first set of holes twice before moving the block, then slow the drill speed down on the second set of holes.

All in all, my impressions of the Beadlock system were overwhelmingly positive. This simple jig brings mortise and tenon joinery within the reach of all skill levels, providing an inexpensive way to produce perfectly fitting, repeatable, error-free joints every time, with nothing but a drill and saw.

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There are three steps to using beadLOCK's system. With the stock to cut to size, begin by drawing a witness mark across both pieces, right where the center of the joint should lie.
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Next, clamp the jig to each part in turn, lining it up with the witness marks. Drill holes with the jig at the "A" setting, then switch to the "B" setting and complete the drilling.
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The third step is to cut the tenon stock to length and dry assemble the joint to check the fit. Then you're ready to glue up and clamp the mortise and tenon joint together.
20772-1.jpg (4941 bytes)Loose tenon stock (available in 3/8" and 1/2" dowel diameters) should be trimmed about 1/8" shorter than the combined depths of the mortise to allow for glue relief. For offset joints, where the mortise isn't centered on a standard piece of 3/4" thick stock, the factory provides a set of shims.
Copyright Woodworker's Journal  Volume 24, Issue 1 February 2000
posted on February 1, 2000 by Rockler
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