Friday, July 16, 2010

Cutting A Channel

With the heatwave over, we can work much more comfortably in our workshop. In fact, we had a tropical downpour midweek, which left us with water leaking all over our work on the shelves. Not good! A typical British summer then.



This week, we have had an intern working with us from the Brit School, who was delightful and a pleasure to work with. He even designed a shoe with us which we think we are going to sample. Watch this space.

We have had a request from a shoe mender for a description of cutting a channel in a sole. So Simon, here you go.

Most leather soled factory shoes are stitched straight through the sole into a groove which protects the stitches. While this method is perfectly functional, it is not the most aesthetically pleasing option, as the stitches remain visible.

With handsewn bespoke shoes, we always hide the stitches by cutting a channel. This is a flap cut into the sole, which is lifted, so that when the stitches come through and the flap is flattened down again, they end up being hidden and, thus, invisisble.
You end up with a perfectly smooth and unblemished sole - gorgeous!

Once your shoe is welted, the shank and cork filler put in, you are ready to attach the sole. The first thing to do is soak your sole leather. This is vital because if you don't, it will be too hard to cut the channel.
Soak for at least an hour and then leave it to dry until it is mellow (about 85-90% dry). At this stage, the leather should still be flexible and supple and dry enough for the glue to work.

Place the shoe on the flesh side and draw round it leaving a 5mm margin and a 1cm one around the heel.




You now need to hammer the sole to compress it so that it lasts longer. If you don't do it, the sole will wear out very quickly. Don't hammer the edges however, because it will be too difficult to stitch through.
You need to use a flat hammer. If you don't have one, grind a domed one down on a grinding machine.



Now trim the sole to the line.



Place the shoe on the sole and holding the two together, trim closer, so that not much spare sticks out. If you don't need to aim for a specific final sole thickness, you can leave more spare leather. If you need a specific final sole thickness, you need to skive the sole to the desired thickness and then trim it very close to the welt. At the end of this process, draw a line on the sole where the welt sits, so that you can place the shoe on the sole accurately after you have glued it.



Now you are ready to glue the sole on. Use rubber solution because if you need to repair the shoe, you can take the sole off without pulling out the cork filler and the shank. Put the glue on both surfaces and let it dry for ten minutes. Place the shoe onto the sole following the line you drew previously.





You now have the shoe and the sole attached. Turn the shoe over, sole side up. You need to nail the heel in place. Mark your heel points. Draw a line around the sole so that the nails will go in about 1cm away from the edge. The line must finish 1cm from the heel marks.



Using 20mm nails, hammer them about 15mm apart, stopping behind the heel marks. Make sure the nails go in at an angle in towards the centre of the heel. About 15 degrees off vertical.
Leave the top of the nails sticking out.



Clip the top of the nails off with nippers.



Punch the nails with a punch so that they sit just under the surface.



Trim any excess leather off the sole, so that the welt and the sole are perfectly aligned. You are now ready to cut the channel.



Drag your nail around the edge at 45 degrees so that you leave a mark on the edge. This is your guide for cutting the channel.



Using this guide line, and starting just behind the heel mark, start cutting the channel with your exceptionally sharp knife. Things to bear in mind. You must cut the channel deep enough to stop the stitches making the bumps on the finished sole. But you must not cut it so deep that you cut through the sole. If you do this, you must start again. So no pressure then. Aim to cut about one third the thickness of the sole.
The angle is about 15 degrees and the channel must be about 8-10mm wide.
Go all around the shoe to just behind the other heel mark.



Open up the channel with a screw driver.



Now you need to make a small groove in the channel for the stitches to sit in. I use a broken awl which I have sharpened into a point.
Drag it round the channel on the inside edge.



You are now ready to start stitching.

By the way, that paste oozing out of the shoe in the last picture is because I use paste on the welt because rubber solution can leave a tiny line on the finished edge. Paste avoids this problem but is more of a fuss to do. Your choice.

Hope this is clear. Please get in touch if you have any queries.

Good luck and until next week, happy shoemaking.