All,
I've been following this thread with no little interest to see where it might go before I jumped in and dropped "the bomb", as this essay has become
'Edge Closing 101"--
Note: "round closing" (plus "flat closing" ), "split and lift" closing, being called butt seaming here, are a family of sewing stitches known as "edge closing", i.e., sewing "with a split-hold" (the awl splits through the substance of the leather--the stitch is only biting through part of the substance at the edge)--versus "stabbing", or stitching straight through, in one side and out the other like a sewing machine does. The "hold" (the purchase taken in either piece of leather being joined in depth and in distance back from the cut edge) is made with a very small curved awl blade (1 1/2" to 2" long) entering the surface, dipping down, then exiting the cut edge, entering the other cut edge, then curving up and exiting on the surface of the other piece. Bristles are essential for sewing this seam. I recommend you use linen thread, the same wax you use for inseaming, and loop the thread on the left-hand side to form a half-cast stitch (half-hitch knot) as when welt sewing. Pre-spun linen machine twist in 3 cord 18, 3 cord 25, and 3 cord 35 are available in small spools in white, brown, and black from Windmill English Saddlery (Ohio, USA), or from Abby Saddlery (UK). Bonded nylon machine thread will be too stretchy, and good on you if you can make a taw on the end, much less keep your bristles on nylon thread. Three cord up to 7 cord linen stitcher threads work fine here as well, if you have this on hand.
These stitches are made one at a time by eye (you may trace a faint line a little in from the edges to follow if you must), i.e. pierce the hole, make
the stitch, pierce the next hole, make the next stitch, etc. No pre-holing, or nothing will align right. This sewing is done by eye--actually by feel--because when you pierce with the awl or pull the stitches in tight the leather puckers-up into the round bit, and as you sew along the leather may get softer/firmer so you will need to carefully adjust your hold to compensate. Under no circumstances should you slavishly follow pre-marked holes rolled-out by a pricking wheel. The result will be anything but precise, because the leather will not accept the stitches evenly when drawn in tight. When correctly done there should be no evidence of sewing on the reverse side, at least no thread showing/breaking through.
The two pieces being joined are butted together edge to edge in their proper position over an arched wooden block (imagine the thick end of a baseball bat, sawed in half, about 5" long) "D" shaped with the flat bit down. This is held along the left thigh to keep the pieces in them in the proper attitude and alignment. You are of course working while seated on a low bench or stool, as for sewing the welt, etc. If the work is butted together on a flat surface, the leather is not arched, and the awl consequently cannot make a tight neat seam of proper depth close to the edge--the "secret" is, the leather must be supported from below in an arc over the "closing block"; then a stirrup strap is passed over the work to hold it in place leaving hands free for sewing, just like when you sew the welt/stitch the outsole. My stirrup for closing is 1 1/2" wide, and has a cut about 12" long down the center so it can be spread open to create an opening for working in. Half the stirrup is holding the work above, and half below the area you're sewing, working in the opening through the stirrup.
Any good leather can be "round closed", but for best results it ought to be tight, plump, whole-grain (not splits) veg (or a lot of veg in a re-tan) and preferably well curried and mellow. Best to test by closing some scraps first. If upon drawing in the stitches tight and hard with a hand leather (on the left hand) and using the knob provided for this purpose on the end of the awl-haft on the right as a capstan, the thread wants to cut right through, you're sewing through "cheese"--not advisable. If, on the other hand, when you pierce your hole with the awl (dipped in beeswax at each piercing for lubrication) the leather tears out as the awl goes splitting through--again, probably not advisable to attempt edge closing on that leather.
Absolutely no need for the uppers to be 8-9 oz veg! Who said that?
We routinely round close uppers varying in weight from 3.5-4 oz. to 5-6oz. maximum thickness. On the thinnest leathers you just have to be careful is all, and not be as strident with the awl or pull the stitches in as tight as you would on stronger skins. We are finding it increasingly difficult to get leathers that will hold high numbers of stitches per inch without cutting through. Eight to 12 per inch is about as fine as you dare try, though in the "old days" perfectly utilitarian uppers (not prize work at all) were commonly edge closed at 12 to 15 or more spi. Chrome leathers are not as satisfactory for edge closing as veg, but then chrome leather is not as satisfactory in most respects, as it is about as close to lifeless plastic as one could make from an otherwise perfectly good animal skin IMHO.
After you've closed your seam, tap it down flat (lightly!), the butt of the awl-haft works nicely for this. Or, you can find/make a light wooden
version of the iron paste-fitters' hammer. Take the sharper end of a bone folder, or other similar stick, press it up against the outside of the row
of stitches and push them in hard towards the middle of the seam to straighten-out any errant stitches, and make a nice clean line of it. Do
both sides of course. Then rub down the "round" hummock bit hard to burnish it. There are (were) special iron seam-setts for setting the stitches (IOW round closing, flat closing, and stabbing seam-setts), used heated to momentarily soften the waxed threads and thus easily move the rows tightly up into a line. Afterwards the seam is painted (with your finger) with gum tragacanth ("gum dragon" ) to saturate and harden it. But, all this is probably too much fuss and finesse if you're only doing this once in awhile, or using chrome leathers.
Someone asked about edge-closing on the grain, on the outside of the work. This is risky, but it can be done. My advice is to take care that the point
of your closing awl is not sharpened off round the sides or it will tend to cut the grain on either side of the actual hole, especially if you wiggle it through, as most of us are in the bad habit of doing. When pulling-in the stitches, you must expect a little cutting of the grain on either side of the stitch hole, but if after an inch or two of experimenting on scraps, the grain separates, cuts, or comes up in tatters at each hole, that leather will not do for edge closing.
Okay now... "round closing" produces two parallel rows of stitches with a drawn-up round (hence the name) hummock of leather down the middle where the two cut edges met. The cut edges must be dead-plumb--there is usually no skiving or angle cutting involved. "Split and lift" closing, as used putting boot tongues into the opening in the bottom of the boot leg is a different matter. As the name implies, this seam "splits" the hold on the edge of one piece, and actually digs into the surface, then up and out on the other, hence "lift". In other cases, this stitch "splits" the hold on the thick side "A", and stabs through the folded-up edge of the abutting thinner piece "B" rather like this:
A=============I________________B
Both techniques are used on English riding boot tongues and expose no stitches to wear on the outside (where the stirrup iron can rub right through them). Why not just round close the tongues inside then? Traditionally/properly, the leather (flesh-out waxed-calf) is thicker for the vamp and counter, and marginally thinner/lighter for the boot leg. This means you're facing edge closing two different weights/thicknesses of leather--round closing only works satisfactorily when edge closing two identical weights of leather. Split-and-lift closing, as in the diagram above, is done similarly to round closing on the closing block, the work is held down by the stirrup. The awl enters the thicker piece (the vamp) first, exits its edge, then pierces (stabbing) right through the upturned edge of the thinner adjacent piece (the boot leg). This creates a combination hold: split on one side, stabbed on the other. No law says the seam must be the same hold on both pieces, but this is too complicated to get into here.
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Here is a detail shot of the side of a boot I made several years ago--nothing fancy, just bare-bones. It shows the juncture of the tongue, the vamp-wing, and the counter. On the upper left is a row of stabbing stitching the top-line of the counter to the boot leg (this seam can be done "split-and-lift" outside for a nicer effect, but I was in a hurry); the slightly angled seam going up and down in the middle joins the front-facing edge of the counter to the back edge of the vamp-wing, and is round closed on the outside (note how the round hummock protects and recesses the threads); on the right is a bit of the tongue-closing at the boot leg, done split-and-lift on the inside. As this was waxed-calf, the tongue closing (always done inside) is consequently on the grain. Hint: because a boot's tongue closed to the leg inside must stand for the life of the boot, and in nearly impossible to repair, this inside seam is nothing pretty. Use stout strong threads, plenty of wax, and adjust the hold, depth, and pitch of the closing with every stitch for maximum strength and solidity--it's better if stitches wander out of perfect alignment, as long as each stitch takes and grabs a good strong hold.
There is "flat closing" too, but this has gotten too long as it is. I would encourage any of you who want to try this to suffer(?) through reading John F. Rees 'The Art and Mystery of a Cordwainer' (London, 1813). He goes into excruciating detail on all these stitches, their applications, and the pros and cons of each in his rambling Georgian English. The important point to note is, edge-closing is much stronger than stabbing (over-lapping), because you are drawing the two edges together, butting them, and the quantity of thread and the all-important wax in the work is greater. Over-lapped and stabbed seams want to sheer, that is the over-lapping layers are pulling against the threads at a right angle=weaker. Even if you stab face to face, and open out the seam, it is still weaker than edge-closing. The little round hummock that rises up in the middle of the edge-closed seam stands proud of the thread protecting it from rubbing, and the threads are recessed on each side in the little valleys it creates. One would be rather hard pressed to find any surviving leather shoes or boots that were not edge closed in some manner from the late 1500s right up to the early-mid 1800s(when uppers got lighter-weight, and full linings begin to creep in). Edge closing proved its worth in strength, and left no lumps or seam allowances inside to rub the foot.. Throughout the 16th, 17th, and 18thc. most uppers were made un-lined in the modern sense, and stouter leathers were the norm (4-5-6oz.). Inside stiffening and reinforcement was done commonly by whip-stitching (not showing outside) pieces directly to the upper, at the toe, heel, or along the lower sides, i.e. side-linings.
I might add that the "rustic" appeal of the "dog-leg" side seams was for added strength. Even in modern Derby shoes, the side seam between the vamp and quarters is still a curved "dog legs". It is clear that a compound angled seam distributes the stresses placed on it tangentially to any one angle of the side-seam, so they are not so apt to pull apart or break open in wear. If you make your side-seam more or less vertical from the sole up, it is inherently weaker because the forces applied to it in walking are trying to pull it apart. For those of you familiar with making or wearing Civil War style bootees ("brogans" ), these combine the worst of both worlds so to speak. The side-seams are vertical, only slightly angled, and they are over-lapped and stabbed through, and they blow-out with not much wear at all. I've worn the same "dog leg" side-seamed shoes everyday for almost 20 years, and have never had a side-seam fail. The bottoms will let go long before the side-seams let go.
BTW, "tunnel stitching" is a made-up term circa late 1960s, invented from thin air by the late John Thornton to describe a running stitch that wormed (literally) it's way from one piece to another on Roman-Medieval sole repairs. The term has been imprecisely bandied about for all sorts of edge-closing seams, because people did not know the traditional terms. It's too late to make this term go away because it's already in print and current everywhere, but no shoe or bootmaker would have known what you meant by saying "tunnel stitch"--it's museum jargon.
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Here's a side detail of a plain-Jane, English-made, grain-out, top boot c.1780, recovered from the wreck of the British ship "The General Carleton of Whitby", now held by the museum of Gdansk, Poland. This boot brings to 7 or 8 the total surviving 18thc. English top boots we have to study. Note, it is entirely round closed inside (on the flesh), and still holding up quite well.
Al