Tag Archives: dovetail

Wraparound Dovetails – How I Fit Them

Most of us are familiar with the techniques for fitting dovetails during construction.  You cut the pieces to size, mark your dovetails, and cut away.  Even if you machine-cut, the process is basically the same.  Everything is measured from the end of the board.  However, there are times when this approach doesn’t work.

This blanket chest is a perfect example of this.  Christopher Schwarz’s Anarchist’s Tool Chest is another.  In both cases, a base or dust seal wraps around the basic structure of the chest, and is dovetailed into place.  The problems start to arise when you realize that the pieces cannot be precut to length, but must be fitted to the existing structure to ensure a good fit.  No, measuring with rule is not a substitute for a good direct measurement.  Of course, your measurement doesn’t tell you how far past the end of the casework the board should extend for the overlap that will give a good, snug dovetail.  This is how I do it:

Dovetail Tuning 1

Start by dovetailing one corner to act as a reference, leaving the board overlong.  Then, with the assembled dovetail snugged into place, mark the corner of the casework on the other end.  A marking knife will work, but I find that a pencil will angle into the corner more easily without wandering.

Dovetail Tuning 2

Next, stand the opposing board (or an offcut of the same) on edge on this board, with the inside edge flush with your pencil line, and mark the location of the outside face.  This measurement isn’t really critical – you just don’t want to be too short.  Next, crosscut the board to just outside this last line to establish the rough length.

Dovetail Tuning 3

Now comes the trick.  Take your marking gauge, which you already set while cutting the first dovetail, and place it against the sawn end of the board.  There will probably be, as shown above, a gap between the knife/pin and the pencil line.  Simply plane away the excess with your shooting board (you do have a shooting board, don’t you?) until the marker touches the far edge of the pencil line.  If your marking gauge was set correctly in the first place, you should now have the correct amount of overlap to yield a dovetail that wraps snugly around the casework.

With a little thought and modification, this technique will also work with dovetailing jigs.  Simply set your marking gauge to the base of the first dovetails, and proceed as above.  Since all you’re doing is effectively cutting a board to length, the dovetailing method is really irrelevant.  Give it a try!

Blanket Chest – A Firm Foundation

The base of the chest was intended from the start to be simple.  My wife didn’t want any feet, openings, or anything of the kind.  She just wanted a simple base or skirt of the type you’d find on a tool chest.  And what mama wants, mama gets.  Besides, what could be easier?

Having read Christopher Schwarz’s The Anarchist’s Tool Chest, I chose to dovetail the base, rather than using miter joints.  This chest would sit on carpet at the foot of the bed, and be dragged back and forth when vacuuming.  Due to this, I felt the extra strength of dovetails would be worth the trouble.  There’s no point in going into the details of cutting through-dovetails – that has been covered by others ad nauseum.  I will, however, cover my technique for getting tight-fitting wrap-arounds with dovetails in my next article.

Blanket Chest 36

I decided on cutting my base 3 1/2″ wide.  This was done by the scientific approach of laying different widths of wood up against the bottom of the chest and, with my wife’s input, deciding which one looked best.  Once the dovetails were cut, the same approach was used to determine how far the base should overlap the bottom of the chest.  We settled on a 2 7/8″ reveal before applying the cove molding.  Yes, that’s almost the entire width of the frame.  However, there are still the bottom boards that project below the frame to be taken into consideration.

Blanket Chest 37

I cut internal supports for the chest from whatever plywood was handy around the shop, and believe me, my pile is as bad as anyone’s.  After ripping to width, they were glued and brad-nailed into place.  As you can see, there’s still an adequate amount of recess to make everything secure.

Blanket Chest 38

Then, the dovetails were glued together around the chest, and the base was attached to the bottom boards with pocket screws.  As we know, in cabinet construction, there’s primary wood, and secondary wood.  But, as the above picture shows, there’s also tertiary wood.  This is one case where your ugliest plywood is perfectly acceptable.

Blanket Chest 39

Here you can see the base fully assembled with the dovetails planed down.  The construction, as it stands, is perfectly acceptable.  However, there’s a certain starkness to it, as though something is missing.

Blanket Chest 40

That’s where the molding comes in.  It adds that needed transition, and harmonizes with the smaller cove molding around the panels.  If I had been using a clear finish, I would have used 23 gauge pins.  However, a painted finish allowed the use of spackling compound, so I stuck with the bigger brad nails and glue.

That finishes the body of the blanket chest!  Now, it’s time to turn my attention back to the lid.  Stay tuned!

Herman-Style Sawbench – Stretcher Joinery

After I finished the dovetails, and was satisfied (reasonably), I cut the ends to a final length of 19″.  Yes, I know that I said the bench would be 20 1/8″ tall.  However, like Ron Herman’s bench, mine will have feet added to the bottom.  This provides a replaceable bearing surface so that the end of the sides don’t get torn up, and provides a ledge to support the ends of boards clamped vertically.  I made it a point to do this after the dovetails were cut to my reasonable satisfaction.  By not cutting to length any sooner than necessary, I had the option to redo a dovetail that went bad.

Ron used a screwed haunched tenon for the upper stretcher, and a screwed butt joint for the lower.  Both are perfectly serviceable and quick to make.  However, I’m always concerned about screwed joints in components that will get a lot of “wiggle” and, while Ron’s stool has stood up quite well, I decided (as usual) to try something different.

Sawbench 5

I opted for a lap dovetail for the lower stretcher, and a lap half-dovetail for the upper.  I’m not sure why I opted for the half-dovetail for the upper joints.  It doesn’t have any real advantages over the full dovetail.  It just seemed like a good idea at the time.  A close inspection of the above photo will show that the shoulders still need a bit of cleaning up prior to assembly.  Not to worry – I didn’t forget.

Sawbench 6

After all the tails were cut,  I cut the matching sockets (the term pins doesn’t really apply here) in the edges of the end boards.  The basic cuts were similar to dovetail pins.  I sawed to the line, and then removed the bulk of the waste, leaving a small amount to be removed to the baseline, as shown below.  However, this was not the time to grab the chisels and start paring.

Sawbench 7

Lap Dovetail Diagram

While lap dovetails resemble conventional dovetails, they are structurally quite different.  On a regular dovetail, the matching sides of the pins and tails are the primary glue surfaces, and provide the strength.  The baselines where the parts butt together are all endgrain, and have no glue joint strength.  As a result,  we usually undercut the baselines a bit when chopping out the waste without weakening the joint.  On a lap dovetail, the matching surfaces are edge grain on the tail, and end grain on the socket.  The baseline of the socket is actually side grain, which mates with the face grain of the tail.  This is the part that provides the greatest glue strength, while the dovetail shape provides racking resistance.  As a result, the baseline can’t be chopped as in a dovetail, but must be smooth and flat to provide the best glue surface with the underside of the tail.    The question is, what’s the best way to do this?

My tool of choice for this was the router plane.  This modern take on an ancient tool allows you to trim smoothly to a precise depth.  Yes, the power router can also do this, but the router plane has one tremendous advantage:  A slip of the hand won’t ruin the entire piece.  Yes, you can make a jig for the router, but that’s an extra step, and requires electricity.  Aside from this, the setup for either tool is remarkably similar.

Sawbench 8

The first step was to clamp a block of wood level with the edge of the workpiece.  This will provide an additional bearing surface for the router plane’s base to ensure that it remains level throughout the cut.

Sawbench 9

My Veritas router plane has an excellent depth stop.  This allows me to set the maximum depth of cut to the finished depth of the socket.  Then, I can back off and slowly work down to that point.  Believe me, the last thing you want to do is try to cut too deep with a router plane!  As you can see above, a good sawing job on stock removal doesn’t leave a lot for the router plane to remove.  If you’ve got a bit more, you could of course use a chisel to get close to the baseline before switching to the router plane.  The result is a glass-smooth bottom on the dovetail socket in a very short period of time.

Sawbench 10

After a good dose of Old Brown Glue, the whole lot goes into the clamps.  Hmm, you know, it’s actually starting to look like something!  Next time, we’ll make the feet and attach them.  Stay tuned!

Herman-Style Sawbench – Panel Prep

Sawbench Crosscutting

Once the panels were out of the clamps, cleaned up, and planed flat, it was time to start building.  The first step was to cut the panels to final length.  This was the perfect job for my Disston No. 7 12ppi crosscut panel saw.  This is not a common filing, but it’s perfect for this sort of cut, where you want as smooth a finish as possible.  The next stop would be the shooting board, and the better the finish here, the less work there.  As you can see, there was a considerable amount of overhang on my existing sawbench, which was one of the reasons for wanting a new one.

Sawbench Shooting

As usual, I cut just outside the line for final length, and used my shooting board and Veritas jack plane to trim things up.  This plane, coupled with a 25 degree iron, is ideal for shooting board work.  It has plenty of mass, is easy to adjust, and leaves a beautiful finish on the end grain.

The two end pieces were a little bit wider than the top, so I ripped them to rough width, again on the sawbench.  My ripsaw kept bumping into the splayed legs of the bench, causing me aggravation and giving yet another reminder of why I was doing this.

Sawbench Planing to Width

Once I had the boards to rough width, I clamped them together and planed them simultaneously to the same width as the top.  A careful examination of the above photo will show a slight difference in width remaining as the planing progresses.  I probably should have clamped the pair lower down to give me a better planing angle, but dropping them in the top of the face vise was convenient, and the angle wasn’t too bad.  In any event, I didn’t have any trouble with it, so all’s well that ends well.

Sawbench Dovetailing

The last task for the day was to cut the dovetail joints connecting the top and sides.  This was a treat, as it was my first chance to use my new Bad Axe Wyatt Earp hybrid dovetail/small tenon saw on a real project.  I won’t bore you with the details of cutting dovetails, since this subject has been (more than) adequately covered by other writers.  Suffice it to say that the Wyatt Earp did a fantastic job on the thicker stock, providing a perfect balance of speed and control.  Dovetailing pine is a mixed blessing.  It’s easier to get a good fit between pins and tails due to the compressibility.  On the other hand, I tent to overrun my baselines when chiseling out the waste due to the same softness.  It’s not the pine’s fault, I just need more practice.

By the way, the presence of the Bad Axe coffee cup was not contrived.  I just happened to be using that cup and, as usual, set it down by my work spot.  No, really!

We’ll get to the rest of the joinery next time.  Stay tuned!

Review: E.C. Emmerich Dovetail Plane

Most of us have something on our Christmas wish list that we didn’t get – the thing that you turn around and spend your cash gifts on.  In my case, it was a dovetail plane.

I like the idea of sliding dovetails for casework, but find fitting them to be a pain.  Routing the socket is simple enough, but fine-tuning the router table fence for a perfect pin fit can drive me to distraction – all I have to do is breathe wrong to get it too loose.  It seemed to me that routing the pin a hair fat and then final fitting with a dovetail plane would be a solution.  Since Lee Valley still had free shipping, I went ahead and ordered an E.C. Emmerich from them.

Dovetail Plane 1

Dovetail Plane 10The plane arrived in good condition, with the iron separately packaged, and included a wrench to adjust the nicker.  The body is beech with a hornbeam sole, and is built along the same lines as their moving filister plane, but without the depth stop.  The sole has a 10 degree slope, and has threaded inserts for the fence adjustment screws.  The fence itself is simple and basic, and has a small machined recess to prevent contact with the blade.  There is a metal button on the rear to act as a striking point for the plane hammer.  The wedge seems unusually long, and may interfere with the blade as it gets ground down.  Of course, the wedge can be trimmed to match when that time comes.

Dovetail Plane 11The blade was surprisingly well ground, and only required a couple of minutes to flatten to my satisfaction.  The skew angle is actually about 14 degrees, which seemed odd until I remembered that this is a compound angle situation.  The sole is 10 degrees, and the blade is bedded at about 45 degrees, requiring a different skew angle on the blade.  The bevel is 25 degrees, and I finished it off with a 27 degree microbevel.

Dovetail Plane 5This plane has the new-style square nicker that is adjusted by loosening a screw and rotating the point to set the depth of cut.  A word of advice here:  use the shallowest depth that will give you a clean cut.  An overly aggressive nicker setting will result in some serious shoulder tearout.  The instructions tell you to rotate to a new corner when the nicker gets dull, and then simply replace the nicker when worn out.  The problem is, I can’t find a source for replacement nickers. Even Emmerich’s catalog doesn’t seem to list one.  Oh well, there’s always sharpening.

I tried the plane in two different modes: dovetail from scratch, and trimming a router-cut dovetail.  Both of these were done both with and across the grain to simulate various types of applications.  I used a variety of woods for the test – the photographs below were of soft maple.

Dovetail Plane 9Cutting with the grain went very well.  The shavings were smooth, even, and full-length.  The only problem, shared by many planes, was that the mouth and side escapement tended to clog with shavings.  As you can see from the picture, the shavings tended to make tight curls, which bunched up and filled the space above the mouth.  This is a function of the fact that the blade’s cutting profile is skewed, and really is little more than an annoyance.

Dovetail Plane 8Crossgrain cuts, such as on the end of a shelf, proved more of a challenge.  The cuts here were noticeably rougher, and the plane tended to chatter more.  As you can see from the photograph, most of the roughness was concentrated on the widest point of the dovetail.  Just to be on the safe side, I resharpened the iron and tried again with the same results.  The best results were obtained by setting for as light a cut as possible and using a sharp iron – just like best results with any other plane.

Dovetail Plane 6There are several reasons for the rough cut.  First, you’re planing crossgrain – that alone makes for a rough cut.  Secondly, as you can see from the photo at left,  while the blade is skewed, the mouth opening is not (yes, that’s my blood on the hornbeam sole – skew points get sharp!).  This means that the gap in front of the blade gets wider as you move farther from the dovetail shoulder, giving less support for the cut.  Thirdly, as you can (hopefully) see from my crude diagram below, the grain at the far end of the dovetail is composed of very short fibers as a result of the nature of the cut.  In most woods you can get tearout here by flicking this point with your fingernail.  Given this combination of factors, crossgrain dovetail tearout is practically unavoidable.  The only possible fix I could think of would be to make a sole insert that would tighten the mouth and conform it to the cutting profile of the blade.  That may be a project for later on if the roughness causes joinery problems.

Dovetail DiagramAll in all, I’m very pleased with this plane.  The overall fit and finish are excellent, reflecting top-notch German craftsmanship.  It cuts well, and is perfect for removing that last hair from a routed dovetail.  You will, of course, need a 10 degree dovetail bit to match the plane, but that’s a minor expense.  My only suggestion for improvement would be a revision of the mouth to give a tighter opening and improve crossgrain cuts.  Final assessment:  an excellent, though specialized, addition to your plane collection.