Sliding dovetail instead of a standard mortise and tenon

[Mike Hess]

I'm thinking of using a stopped sliding dovetail joint for my next project

This would be for a drop-leaf table where the rails meet the top of each leg. I'd like to use a very strong, stiff joint here as I won't be using a set of lower rails - they would be real shin bashers when the table is deployed in "additional dining area" mode.

Am I on the right track here, or would a standard mortise and tenon be plenty strong? Am I setting myself up for unnecessary frustration?

[Ben Davis]

I guess that depends on what would be faster for you to construct accurately. The M&T will be quite strong. The sliding dove tails might be easier if you have the right jig though. I say either way you'll be good to go.

[Mike Hess]

I guess that depends on what would be faster for you to construct accurately. The M&T will be quite strong. The sliding dove tails might be easier if you have the right jig though. I say either way you'll be good to go.

To make the slots, I'd use a large dovetail bit on the router, and then clean up the rounded end by hand. To make the dovetail shaped tennons, I'd use my (accurate, well aligned old Dewalt) RAS in crosscut mode, set with the blade a few degrees off horizontal (to match the slope of the dovetail). I'd make an angled cut across the end of the stock, flip the stock and repeat. May require some minute blade lowering to fine tune it, but once I had it positioned (and a length stop set) I could make all of the angled cuts easily. Then reposition the blade to vertical, reset the depth and the stop and make all of the shoulder cuts.

It would require some test pieces, but once I had the setup dialed in, it would be easy to run all of the pieces.

[Jamie Buxton]

If you believe in glue, the M&T would be just as strong. In fact, you can probably make it deeper than the sliding dovetail, so it would have more glue area.

If you don't quite believe in glue, you can also cross-pin the tenon. You can make it hidden by doing it from the inside, or you can make is visible by driving it from the outside.

[Mike Hess]

If you believe in glue, the M&T would be just as strong. In fact, you can probably make it deeper than the sliding dovetail, so it would have more glue area.

If you don't quite believe in glue, you can also cross-pin the tenon. You can make it hidden by doing it from the inside, or you can make is visible by driving it from the outside.

Hmmm - a pinned tenon is something I hadn't considered. Hmmmm.

[Mike Cutler]

You are very much on track.
Pick up just about any book on joinery and it will detail a joint very similar to what you're planning, for the same joint.

[Howard Acheson]

>> This would be for a drop-leaf table where the rails meet the top of each leg. I'd like to use a very strong, stiff joint here as I won't be using a set of lower rails

A sliding dovetail is frequently use for the joint you describe. It's inherently stronger than
a M&T joint. Properly made, it will be tight even with out adhesive.

It's a finicky joint to make right and you still need to worry about cross grain problems if the joint is longer than four inches or so.

[pat warner]

Not a lot of cutters for this and some corner joinery may require reinforcement (cornerbraces, hardware etc).
The whole picture at DW (http://www.dewalt.com/us/articles/article.asp?Site=woodworking&ID=511).

[Doug Shepard]

There's some pics on this thread of some end tables I did with a joint that has the backside of the aprons attached to the legs with sliding DTs. Post #16 has closeups of the joint from the FWW issue I got it from.
http://www.sawmillcreek.org/showthread.php?t=15882
I did glue these, but I had a number of dry fits in order to get the joinery for the lower shelf laid out and cut. Even without the glue the tables were rock solid. The double miter thing is a bit overkill, but even just a single miter at the corners, with the rails sitting on a notched out shoulder at the top of the leg, combined with a DT at the back would be very strong. Plus you'd not be gluing endgrain.

[Rob Cunningham]

To make the slots, I'd use a large dovetail bit on the router, and then clean up the rounded end by hand. To make the dovetail shaped tennons, I'd use my (accurate, well aligned old Dewalt) RAS in crosscut mode, set with the blade a few degrees off horizontal (to match the slope of the dovetail). I'd make an angled cut across the end of the stock, flip the stock and repeat. May require some minute blade lowering to fine tune it, but once I had it positioned (and a length stop set) I could make all of the angled cuts easily. Then reposition the blade to vertical, reset the depth and the stop and make all of the shoulder cuts.

It would require some test pieces, but once I had the setup dialed in, it would be easy to run all of the pieces.

Either joint would be appropriate and strong. However, I cringe thinking about cutting the parts on a RAS.(Unless I misunderstand you) A dovetail bit in a router table I feel would be much safer and easier to set up.

[Tom Esh]

I like sliding DTs and they often work as well dry as glued. However if gluing, you have to be especially careful with these grabby PVA glues that the whole thing doesn't sieze up before you can slide it home. The dry fit is absolutely critical and should require little or no force. The way these joints bind and the way you free them is almost counter-intuitive, so if you haven't done sliding DTs before, use the dry fit to develop your assembly technique. ...and have a hammer handy when gluing just in case:D

[Mike Hess]

Not a lot of cutters for this and some corner joinery may require reinforcement (cornerbraces, hardware etc).
The whole picture at DW (http://www.dewalt.com/us/articles/article.asp?Site=woodworking&ID=511).

The third picture in Pat's link is pretty much just what I had envisioned.

Regarding the cross grain situation, the length of the tenon, whether it's rectangular or dovetail shaped would be about 3.5" so I don't anticipate it being a problem.

[Mike Hess]

Either joint would be appropriate and strong. However, I cringe thinking about cutting the parts on a RAS.(Unless I misunderstand you) A dovetail bit in a router table I feel would be much safer and easier to set up.

Unfortunately, I don't have a router table. It's on the "gear to get" list, but I'm just not there yet.

To cut on the RAS, the rails would lay flat on the table and be clamped against the fence, and then the blade passed through the end of them at an angle a few degrees off horizontal.

I don't think that would be terribly unsafe, unless I'm missing something?

[Vince Shriver]

I'm thinking of using a stopped sliding dovetail joint for my next project

This would be for a drop-leaf table where the rails meet the top of each leg. I'd like to use a very strong, stiff joint here as I won't be using a set of lower rails - they would be real shin bashers when the table is deployed in "additional dining area" mode.

Am I on the right track here, or would a standard mortise and tenon be plenty strong? Am I setting myself up for unnecessary frustration?


These folks make a jig for sliding (locking) dovetails. They show a picture of a cabinet locked up with the sliders and NO GLUE. The joint is significantly stronger than a M & T, but does take a little more effort to produce. Their jig should make it very doable, however.

www.allendesignsllc.com (http://www.allendesignsllc.com)

EDIT: I just taled to the guy at this company and they are temporarily (hopefully) out of stock. Apparently the guy who was supplying them went under and Allen Designs is trying to source another supplier. Vince

[Gary Curtis]

Mike, when I was constructing wall benches for my newly-built workshop I used sliding dovetails with Doug Fir 4x4's for legs, and 2x6's for aprons.

I used a HSS dovetail bit sold through the Craftsman Gallery ---- www.chipfly.com. The bit I used is 15/16", although they sell one even bigger--- a 28mm, which works out to be about an inch-and-a-third. Strength? Well, in order have some flexibility I didn't glue any of the 30 joints I cut. The benchs have knock-down cability.

Gary Curtis
Northern California:)

[Rob Cunningham]

Unfortunately, I don't have a router table. It's on the "gear to get" list, but I'm just not there yet.

To cut on the RAS, the rails would lay flat on the table and be clamped against the fence, and then the blade passed through the end of them at an angle a few degrees off horizontal.

I don't think that would be terribly unsafe, unless I'm missing something?

I think it would work that way, I'm just not a big fan of the RAS. You might want to make the cheek cuts first then your angle cuts.
Making a temporary router table wouldn't be too difficult. That way you are using the same bit to cut all the dovetails. It would eliminate fussing with the angle on the RAS.
If you do decide to use the RAS, just pay attention to where the blade. Be safe.