Tongue & Groove

[Smoothjazz077]

My current joinery method for joining 2 pieces has been the Butt Joint. I make certain both edges are true as gap free as possible. Thus far, I haven't had a joint fail me yet . In a current project I am starting, I will be making a tabletop for an end table. I will be using Cherry as the stock, and am contemplating whether I should use a Tongue and Groove joint for added strength. How often do other woodworkers use this joint, and do they prefer it over the Butt Joint when joining pieces to make a solid panel.

Scott

[rwe2156]

Smoothjazz077 said:

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My current joinery method for joining 2 pieces has been the Butt Joint.

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A butt joint refers to joining the end of a board to another board. It is hardly even consider a joint and of the weakest nature, of necessity employing screws, dowels, etc.

A little terminology correction. If you are referring to a panel glue up, that isn't really joinery and certainly not a butt joint.

Quote:

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In a current project I am starting, I will be making a tabletop for an end table. I will be using Cherry as the stock, and am contemplating whether I should use a Tongue and Groove joint for added strength. How often do other woodworkers use this joint, and do they prefer it over the Butt Joint when joining pieces to make a solid panel.

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I do not use them at all but I have seen it done. Occasionally I will use a spline for thick material this is easier and faster than T&G.

For a table top glue up, I simply glue them up with no alignment helps.
Good Luck,
Robert

[Mike Brady]

That's a good question. The kind of joint used in a panel glue-up, such as for a table top, requires as precise a fit between the panel edges as possible. The way I do it is to plane the two mating edges at the same time so that the edges are perfectly complimentary to each other. At the same time, I take extra strokes that don't include either end of the joint. This insures that the ends meet; leaving a slight opening toward the center of the joint that is "sprung" closed with bar clamps.

A tongue and groove joint is usually not glued and allows for movement of the boards. It can be glued, but making the seam invisible is a challenge. I also would not use a T&G joint for a horizontal surface unless the panel is supported by structure or nailed to a frame.

Another way to look at this topic is that glued joints are to be as invisible as possible, while T&G joints are utilizing the joints in a decorative way while allowing for natural wood movement.

You will undoubtedly hear from folks who use various means, including dowels, biscuits, loose tenons, T&G, breadboard ends, framed panels, to make table tops. All can work.

[AHill]

If it's a panel for the top you're building from separate pieces, stick with the edge-to-edge glue-up. It's been used for centuries and it holds up extremely well. Just look at any large table, and you'll see that's how it's most commonly done.

[Admiral]

As Mike says, getting an invisible joint is the challenge, which is why splines are used as Alan said.

If you really want to use T&G, the only way I would use them is to celebrate the joint, in the sense of adding a chamfer to the edges to make it decorative. Depends on the style you want to achieve, likely this won't work for a traditional top, but can be very attractive in the right motif.

[Smoothjazz077]

Thanks Allen

[Carl Grover]

The glue in your butt joint is stronger than the wood anyway. I'd say you're good to go.




carl

[hbmcc]

Splines, or alignment for edge gluing were used years ago. I have a dining table and desk that have what look like half-hearted t&g edges. I think, from my reads, the surface advantage for glue bonding was over rated. My tables, both hard maple, had separation anyway.

Alignment dowels, or biscuits, are used occasionally for large glue-ups to more easily align the boards. Your end table is small enough it would never need anything more than flush edges.

You can always design and set up for breadboard ends, if you want more challenge.

[JimReed@Tallahassee]

Sometimes you see finger joints used in factory furniture for alignment. On the surface they look like T&G. Otherwise I think the panel glue up has been covered. Most of us just joint the edges and glue. Done properly with properly seasoned wood these panels will stay together for years.

Mating the top to the frame, however is another issue. Wood expands and contracts perpendicular to the grain when moisture changes. Securing these panels too tightly restricts movement and can lead to subsequent joint failures and even cracks. I like to use the less is more theory and attach tops lightly using Z clips. Everything from bedside tables, coffee tables, and even dresser tops have been attached this way with no failures in 40+ years. I even repair antiques using Z clips. Highly recommended.

[cputnam]

Once you have straight and square edges, or even a spring joint, I am of the opinion that anything else you do to those edges can only weaken the joint. If you believe that glue is stronger than the wood (I do) then you cannot improve the strength because the wood will fail. For alignment issues I tend to favor cauls clamped at right angles to the glue joint.