Shoemaking School Pt. 4 — Outsole Stitching
One of the distinguishing features of truly high end shoes is that they usually hand stitch the outsoles. While a machine can typically do the stitch much quicker, they still can’t get quite as high SPI as a hand stitched outsole, or as close of a welt. That being said, doing a good outsole stitch is no easy task!
Once you’ve finished welting, make sure to take out all the nails
Ideally, you should cut the inner portion of the holdfast all in one go. That way, you can save it and reuse it to fill the void over the stitching.
In this case, I cut quite shallow at the toe area so I had to use cork to level it out. If you can’t do a single cut, or if you didn’t save your cuttings, cork will work just fine to fill that area out.
Make sure to roughen up the bottom of the insole and welt with a rasp before gluing the cork, that helps it adhere. Cover everything within the stitches with a layer of cork, then start shaping it with a rasp. You want the front 5 cm to be completely straight, while maintaining a bit of a round shape at the ball of the foot and the arch.
Don’t make too much of a round shape at the ball though, that will show when you put the outsole on and make the shoe unstable. This is about what it should look like, depending on the last.
Mark out 5 mm around the welt and trim, make sure you’re trimming the welt at a 90 degree angle, otherwise you’re going to have more work later when you shape the outsole.
To prepare the outsole you must first soak it for 5 hours, depending on the thickness of the outsole. Once its soaked, dry it on a newspaper a bit, then roughen up the flesh side with a roughener. Make all of your strokes in the same direction with the roughener, then dry only the flesh side of the outsole. You can use a heater, or a blow dryer. Once the flesh side is dry, apply glue and let it dry for about 30 min. It’s important here to make sure you’re really getting the glue into all of the ridges and such, also apply the glue evenly. If you glob it on, it wont dry completely and adhere properly. Before applying glue to the bottom of the shoe, make sure to use a rasp to roughen the welt. This is especially important because if you don’t get a proper adhesion on the welt, it makes stitching much harder.
Trim the outsole and shape with a glass as best you can make it at this stage, you want it close to the final shape before you channel the outsole. Make sure your cut on the outsole is 90 degrees again. If you angle in after you’ve already trimmed your welt to size, its really hard to straighten things out. When using glass, you should find a straight edge and do long strokes in a pushing motion, applying quite a bit of force. Make sure you’re holding it perpendicular to the edge, so it doesn’t get crooked.
Fudging wheel
When doing the fudging, make sure the welt is wet, then heat the fudging wheel. You don’t want it so hot that it will burn the leather, but hot enough that you can’t just hold it with your bare hands.
It’s okay to go back and forth with the wheel, as long as it stays in the same grooves. Ideally, you do it all in one go, but if you have to lift the wheel make sure you put it back down in the grooves. At the toe, make sure you’re pivoting the wheel as well so the lines are perpendicular. Once this is done, mark out your stitching line. You should make the stitches so that when you look down at the shoe, you can see only half of the thread. Don’t worry too much if your grooves aren’t perfect or deep enough. At this stage, you’re just marking out where your stitches will go. In the finishing process you go over it again multiple times with the fudging wheel.
Stitching awl. I had to modify the point so that its less curved up. Also, don’t be shy about sharpening it.
Using a slightly different thread this time, no putting together multiple strands and spinning, but you still have to use pitch and wax. Unravel the ends so you can attach the bristle.
Use the roughener to comb out the ends before attaching the bristle. The rest of the steps are the same as making the other thread, apply pitch, use a cloth to seal it, attach the bristles, then give a generous coating of beeswax or paraffin.
You want the top part of the welt to be as neat as possible, but if you are off slightly don’t worry too much. After you compact the outsole it closes up the awl holes and makes it look neater. Also, fudging helps hide imperfections in the stitching a bit.
When you’re ready to channel the outsole, trim the edges slightly first, this will help you set the blade.
This is about the depth you should be cutting, and how you should hold the knife. Use your fingers to guide the blade on your right hand, and push it with your left hand. Make the cut at a slight angle, but not too deep. If you start cutting up, through the edge, just back it up a bit and restart. If you don’t cut the channel wide enough in the first go, you can always come back and widen it on the second pass.
Make the cut on the inside of the waist a bit wider than the rest.
Make a few holes with the awl to see about where its coming out.
Use the channel groover where the awl holes come out. Its helpful to mark it out first with a pen, then make a slice with a knife before using the channel groover, otherwise it goes all over the place like in this picture.
Its a good idea to put some tape along the bottom of the shoe before you use the fudging wheel, otherwise you get these marks… Make sure to dust the tape first, or use a tape that doesn’t have a very strong adhesive, otherwise it will take the surface off the leather. When using the awl, you should almost come in vertically as pictured. Make sure to wax the tip of the awl, when you encounter resistance, take it out and rewax. I usually do it in two goes. You start by bringing it in vertically like this, then do a scooping motion and try to come out in the channel. If you notice that your awl head is coming out a bit too far out, just back out and adjust. Its okay if your holes are big, you’re going to compact everything with a hammer later.
Stitching is similar to welt stitching, except you do the twist on the top side of the welt. Always start with the toe of the shoe pointing towards you, make a hole with the awl, put in the left hand side thread and take it under the thread on the right as shown, then thread the right hand side thread and tighten.
Detail shot of the thread going behind the other on the top. Make sure you do this twist on each stitch. Use your hand protector and awl to tighten the stitches.
Don’t forget to periodically moisten the outsole.
Take your last stitch in and leave it untied. This way you’re not leaving a bulge with the knot, and it will all be glued and under a heel anyway. Once done, fold the leather over the channel with the back of your hammer.
When you soak your insole and pierce it with the awl, it spreads the fibers of the leather out. To compact the insole and shape it, just start hammering away at the edges. Before you do this step, you should dye the top side of the welt since the dye can penetrate more before the leather is compacted and the awl holes are closed up, I’ll cover that more in depth in the finishing section.
Besides compacting the outsole, you’re shaping it with the hammer. Here you can see how the left side is raised higher than the right side. Hammering more on the right fixes this. You can see its also dyed here, and some of it got on the upper. Again, this highlights the importance of taping your uppers before doing any of these steps.
After you finish hammering and shaping the edges, do the same with the inner portion of the outsole. Afterwards, use the haft of the hammer to smooth out all of the marks from hammering the sole. Once you’re satisfied with how smooth it is, use your bone folder to open up the channel again.
Finally, use a rasp to roughen up both sides of the channel and apply your contact cement. After waiting about 15–20 minutes to let it dry thoroughly, close the channel and use the bone folder to make sure everything is flush.
This article is also posted on my website, www.arnoshoes.com
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