How to use a Sliding Dovetail

[Andrew Pitonyak]

I am building a Tansu (Japanese chest of drawers) for my wife. For this unit, think of a small chest of drawers about 24" tall and 18" wide and 9" deep. I am basing this off a blog entry and a unit that another person made (unsure if I can link to it). The directions are very vague and they recommend a sliding dovetail for the "shelves" that run between the sides on which the drawers will sit.

I have never done a sliding dovetail.

Do I glue the joint? I vaguely remember (from somewhere) that I should glue only a few inches in the front so that there will be no splits from expansion, and the front will stay put if there is expansion or contraction.

I have not decided if I will do a stopped dovetail or let it run all the way through (I am a bit torn on this).

Should I try to make a tapered sliding dovetail?

[Peter Quinn]

If using yellow glue,,you only want to glue the last few inches near the front or you will never get the joint together, it will lock up first from the pressure. If using a slippery glue like hide or epoxy you could glue more of the joint, but it will get messy as the dovetail essentially acts as a squeegee on assembly. There is no real wood movement issue as all the wood is moving the same direction typically. The tapered version is slightly harder to plan but much easier to assemble and glue IME. Consider that if possible.

[Steve Baumgartner]

+1 re taper. Non-tapered sliding dovetails are notoriously hard to assemble unless they are a sloppy fit. They get stuck part way in and then are nearly impossible to move either direction. With a tapered sliding dovetail, you can shave the tail down a hair at a time until it almost goes home and then be sure of a tight fit when you clamp or pound it all the way during assembly.

[Carl Beckett]

A tapered sliding dovetail just sounds to me like more ways for things to mess up. 9" isn't that far. Cut them so they slide in dry. Then add a 'little' glue along the length ( may not even be needed, but I always add some), and assemble. Have a clamp handy to pull it in place if it gets a little sticky

Run all the grain the same direction and expansion should all go together

[Paul Murphy]

I built a bookcase with regular sliding dovetails, and glued their full length with Titebond Polyurethane glue. The poly lubricated the joint, provided plenty of open time, and has no water content to swell the joint making assembly potentially difficult. All the work is in cutting the tail to the correct fit. That said, I admire the qualities of a tapered sliding dovetail, I just have yet to use them.

[Andrew Pitonyak]

My test joint today was a total failure.... I had one silly little problem after another (I guess that is why you create test pieces to see how it all goes).

I intended to cut the groove using my Festool router, which cannot take a 1/2" bit and almost all my bits are 1/2".

Next stop, the router table. I figured that I would start with two test grooves. The first groove was fine, and then the bit came loose in the second (never had that happen before).

Did not get the proper height when I put the bit back in.......

My front facing fence is a split fence.... and using what appears to be the standard trick of placing the shim on the board, well, at the split, the shim is no longer on the board..... Well, you get the idea.

Guess I will build a quick one piece fence out of plywood and give it another try when I have more time in the shop...

On the plus side, I was able to build my first drawer dividers for my newly built tiny chest of drawers. I really should get a bandsaw so that I can resaw thicker stock down to small stuff rather than running it through the planer until it is 1/8" thick for my small dividers. It was an excuse to use up some of my somewhat damaged stock that needed to be taken down to a small size to remove most of the flaws. One total failure, one success (that had my wife ooing and ahhhhing).

[Carl Beckett]

A couple thoughts Andrew, for consideration:

I wouldnt try cutting long boards crossways in a router table. I dont trust things not to move a little - meaning a groove that doesnt come out straight/square. Instead I recommend the hand router and using a 'dado fixture'. Just a guide that clamps on the board to track a router/bushing across it. You can search here and find a lot of designs (which are all simple, and work well).

Then take a pass on the table saw to make a square groove first. This gets out some waste (dont make it wider than the widest part of the dovetail groove). Having a bit work loose is scary. And possibly just taking too deep a cut. Removing some waste will help.

But a 1/2" collet for your router. I avoid using 1/4" whenever possible, so recommend its your 'goto' size shank whenever possible.

Am sure others will have some good tricks as well.

[Andrew Pitonyak]

I wouldnt try cutting long boards crossways in a router table. I dont trust things not to move a little - meaning a groove that doesnt come out straight/square. Instead I recommend the hand router and using a 'dado fixture'. Just a guide that clamps on the board to track a router/bushing across it. You can search here and find a lot of designs (which are all simple, and work well).

Yes, controlling "wobble" on the router table is tricky at best, which is why I wanted to run the groove with a hand held. Lot of work to remove my router from the table and the Festool simply cannot handle a 1/2" bit. I am leaning towards dumping the festool (1400 I think is the model) and replacing it with a second Bosch 1617. Then, I can do a bit more by hand. If I want something smaller, I can add a trim router to the mix. If my router lift supported a bigger router, I would pull my 1617 from my router table and drop in something with more gusto into the table (not that I have ever needed anything bigger.... but I have never tried a 3" panel bit).

So, I suppose pull my 1617 or get another router to run the groove.


Then take a pass on the table saw to make a square groove first. This gets out some waste (dont make it wider than the widest part of the dovetail groove). Having a bit work loose is scary. And possibly just taking too deep a cut. Removing some waste will help.

I think that I did not tighten it sufficiently.... but I also did not remove the primary waste on that cut either, so you could be right on the later. Turns out my straight bit that I used for the first pass was dull and it worked poorly. Need to sharpen it or get another bit. Sadly, I don't remember what I did to dull it... Hope it was fun whatever it was.

Thanks for your comments. I figured it would be easier to do the groove by hand. Nice to hear it stated flat out.

[Butch Edwards]

never tried to make a slider, but it sounds interesting....

[Frank Drew]

Rout the groove before the tails, then cut the tails to fit, but use the same router bit kept at the same height for both and you can get very precise results.

For the groove, use a straight bit first to remove most of the waste then finish the cut with the dovetail bit, cutting one side then the other if the groove is on the wide side. Keeping the router bit at the same height, run the sides standing up on the router table, checking then refining the fit by moving the fence in minute increments. Helps to have scrap pieces of the exact same thickness as your shelf material to get the cut correct.

I totally agree that a tapered dovetail is way easier at assembly time, but it is more trouble to make. In either case, this is essentially a mechanical joint and won't need much glue, so don't use much or it might lock up on you partway through as Peter and Steve noted.