Stub Tenon Groove

Cabinet Frame Assembly Mortise

Frame and panel construction is one of the hallmarks of traditional woodworking. It's the technique that's frequently used in making doors and cabinet frames.

Typically, a frame and panel is made by joining the frame with mortise and tenon joints. The panel rests in grooves cut along the edges of the frame.

But a mortise and tenon isn't the only joint that can be used on a frame and panel project. If the panel is plywood (or another man-made material). I often use a stub tenon and groove joint. The Oak File Cabinet (page 6) and the Shop Cabinet (page 18) are both examples of this.

mortise -wd tenon. On a traditional mortise and tenon joint, the long tenon and deep mortise provide strength for the frame, see Fig. 1. So. in a frame and panel unit built with mortise and tenon joints, the strength in the unit comes from the joint itself.

STUB TENON AND GROOVE

A stub tenon uid groove joint is a little different from a traditional mortise and tenon. The stub tenon and groove joint doesn't have a "true" mortise. Instead, the groove that holds the panel also houses the short tenon, see Fig. 2. (Also see pages 14 and 15 for more on the groove and stub tenon.)

But the most important difference between the two joints has nothing to do with the tenon or the mortise. It's that a stub tenon and groove joint has a panel that's glued in place.

GLl ED-IN PANEL? Wail a minute. I thought you weren't supposed to glue panels into frames. Doesn't the panel have to "float" so it can expand and contract with changes in humidity? Yes — (/'the panel is solid wood.

And that's one of the main things to understand about this joint. It's usually used with a plywood panel that won't expand or contract — so the panel ca n be glued into the groove.

l ntt strength. When it's glued into the groove, a panel becomes part of the joint. In fact, a frame with stub tenons and grooves gets most of its strength from the inner panel, not from the outer frame and joints. It's like the difference between a lobster and a fish — one gets its support from an outside shell, the other from an internal skeleton.

Aglued-in panel helps tie the frame pieces together so the corner joints don't need to carry all the weight. This means the tenon can be "stubby"; it only has to be as long as the groove is deep, see Fig. 2.

stub tenon. If the glued-in panel ties the frame together, why do you even need the stub tenon? Two reasons. The most important reason is the stub tenon keeps the rail (the horizontal frame piece) and stile (vertical piece) aligned and flush. Then the rail can't twist in relation to the stile. Secondly, the stub tenon fills the end of the groove.

glue surface. Is a stub tenon and groove joint really as strong as a mortise and tenon? No, the joint itself isn't as strong. But once the panel is glued into the groove, the whole unit is stronger. That's because of the increased glue surface. When a panel is glued into a frame, the glue extends all the way around the inside of the frame (the length of all four grooves). The glue isn't concentrated just at the corner joints like in a mor-tise-and-tenoned frame with a floating panel, see shaded areas in Figs. 1 and 2.

Also, modem glues are a lot stronger, and their holding power greater than glues available in the past. So when a piece of plywood (or other man-made wood substitute) is glued into a frame, the entire unit becomes very strong. Probably as strong as one solid piece of wood, but without the problems of w(x>d movement.

GLUING AND ASSEMBLY

Okay, so it's the glued-in panel that makes the stub tenon and groove joint work so well. What's the big deal about gluing a plywood panel into a grooved frame? It isn't a big deal, as long as you keep in mind the technique works because the glue bonds the frame to the panel as a unit. The secret to this bond is an unbroken (continuous) glue line.

mortise and tenon

SOUD-WOOD PANEL MUST "FLOAT" IN FRAME

mortise and tenon

SOUD-WOOD PANEL MUST "FLOAT" IN FRAME

Mortise And Tenon With Groove

stub tenon and groove

MAN-MADE PANEL CAN BE GLUED IN FRAME

stub tenon and groove

MAN-MADE PANEL CAN BE GLUED IN FRAME

Stub Tenons

dry assemble & on e. For the frame and panel to fit together properly as a unit, dry assemble and check the unit for tight joints and square corners before doing any gluing.

Then, to glue up the assembly, spread glue into the grooves of the rails, see Fig. la. Now place the rails onto the ends of the panel, see Fig. 1.

Next, spread glue on each tenon, and also into the grooves of the two stiles, see Fig. 1 b. Finally, slip these two pieces onto the panel.

ci am p. With the frame sections glued around the panel, clamp across the joints at both ends. Then, to keep the stiles from bowing out, place another clamp across the middle of the frame between the first two. see Fig. 2. Tighten this middle clamp until the width of the panel measures the same here as it does at the ends.

Shop Note: To keep the sides of the frame from twisting, the clamping pressure should be centered on the joints. It helps to use a spacer under each frame side, see Fig. 2a. Or you can place a rounded-over block between the clamp and the frame, see Fig. 2b.

EFFICIENCY

Besides being strong, stub tenon and groove joinery is also a quick and efficient way to build a frame and panel unit. After you've cut the grooves and tenons, that's all there is to it. You don't have to cut out a deep mortise.

Plus, both partsof the joint can be cut with just one tool. I usually use a table saw. but you could use a radial arm saw or router.

On pages 14 and 15 we show how to cut stub tenons and grooves using a table saw. Also, shown on page 17 is a jig for cutting tenons with a router.

stile

COTTON SWAB HELPS DISTRIBUTE GLUE INTO GROOVES

Stub Tenon And Groove

RAIL

second:

GLUE SULES ONTO PANEL AND TENONS

GLUE RAILS ONTO PANEL

note:

ALIGN ENDS OF TENONS WITH EDGES OF PANEL

COTTON SWAB HELPS DISTRIBUTE GLUE INTO GROOVES

second:

GLUE SULES ONTO PANEL AND TENONS

RAIL

SPREAD BEAD OF GLUE ON BOTH CHEEKS OF EACH TENON

GLUE RAILS ONTO PANEL

note:

ALIGN ENDS OF TENONS WITH EDGES OF PANEL

CLAMP ACROSS BOTH ENDS OF FRAME ASSEMBLY

Basic Wooden Frame With Halving Joints

SPACER STRIP CENTERS CLAMPING PRESSURE ON JOINT

ROUNDED-OVER BLOCK RE-DIRECTS PRESSURE TO CENTER OF JOINT

CLAMP ACROSS MIDDLE OF FRAME TO KEEP STILES FROM BOWING

CLAMP ACROSS BOTH ENDS OF FRAME ASSEMBLY

CLAMP ACROSS MIDDLE OF FRAME TO KEEP STILES FROM BOWING

SPACER STRIP CENTERS CLAMPING PRESSURE ON JOINT

ROUNDED-OVER BLOCK RE-DIRECTS PRESSURE TO CENTER OF JOINT

Stub Tenon Joints

ROUTED EDGE EXTENDS AROUND FRAME

THICKNESS CAN VARY

MOLDING APPLIED TO EDGE OF FRAME

Images Different Routed Edges

ROUTED EDGE CAN STOP AT CORNERS

Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

Get My Free Ebook


Responses

  • Anna
    How to glue plywood in stub tenon wood panel?
    7 years ago
  • Anita
    How to router groove frame panel?
    6 years ago
  • darcy
    How strong is a stub tenon?
    6 years ago
  • KRISTIN UNGER
    How to keep stiles from bowing?
    6 years ago
  • venla
    How to make stub and tenon cabinet doors?
    3 years ago
  • ward
    What does tenon and groove mean in furniture making?
    7 months ago

Post a comment