I made these sandals a few weeks ago and have since taken a trip to the mountains in them so I can attest to their sturdiness. I did a lot of research to make these because I couldn't find a single tutorial with all the information I needed, hopefully this tutorial answers every leather sandal- making question you can ponder. This is a lengthy but simple process, no leather working experience should be necessary.
Step 1: Materials
Materials I Used:
1. Leather - How much, what thickness, what color, and what kind is completely up to you, I will offer more guidance on leather choice later on.
2. Contact Cement - Every pro cobbler tutorial uses Barge contact cement, I used some Wilsonart 500 contact cement intended for use on laminate countertops because I had it lying around, as long as it is strong waterproof and dries flexible it should work.
3. Leather Awl - my leather Awl is very nice it has a spot for a spool and the bottom holds extra needles but any leather needle Awl will do.
4. Exacto Knife and Scissors
6. Something to Cut on - A marble tile is ideal but a ceramic tile or a piece of wood will work too. Plastic mats are not ideal.
7. Masking Tape
8. Construction Paper
9. Gel Super Glue
10. Leather Cord/ Lacing - This will be for the ankle tie strap.
Step 2: Choosing Leather
To begin with I would highly suggest buying your leather from somewhere you can feel it. I don't know a lot about leather grades or types or tanning processes, and I buy all of my leather as scraps, so I didn't buy any leather for this project specifically.
I used two layers of cowhide and one layer of kangaroo leather, I do know that kangaroo leather is readily available in a wide variety of colors which is how I got the bright teal top sole. It is also not necessary to use three layers, a top and bottom sole are all that you need but I wanted to use the very thin kangaroo leather for my top sole and I did not want to feel the straps under my feet so I knew I would need a midsole.
For my straps I used a piece of cow leather that did not stretch when I tested it, this is the most important aspect of the strap leather.
My leathers approximate thicknesses are:
Teal top sole: 1mm
Bottom sole: 1cm
This makes the distance between my foot and the ground around 14mm, if you want more than that you can either use more or thicker leather or glue a *cringe* rubber sole to the bottom of your shoe.
These are very durable at this thickness and even with them worn in I don't really feel rocks under my feet, but I also enjoy walking barefoot, so to each their own.
My final suggestion on choosing your leather is that if you source it from somewhere random like I have you should test it with water and sandpaper to see how it will wear/ if the dye will release.
Step 3: Patterning
This step is pretty self-explanatory, get out your construction paper and trace your foot, take that and make it shoe-shaped, and then make one that is it's mirror. After you have two soles, you will want to figure out your straps.
I cut a bunch of 1-inch strips of construction paper and fit the straps on my foot and then bent them where they went under, and masking taped them on until I had them all finished. after this I detached the straps again and set them aside so I could use the sole.
Step 4: Cut Out Your Soles and Straps
Lay out the patterns on the leather, mark it with a pen on the side you won't see, and cut them out. for thin leathers like my blue one you may need to tape it down to create tension in order to cut it out with a knife. I didn't take photos of cutting out the straps but I just used a ruler to keep the knife straight and used the patterns to measure.
Step 5: Contact Cement Take 1
1. ONLY USE CONTACT CEMENT IN A WELL VENTILATED AREA SUCH AS THE OUTDOORS
2. FOLLOW THE INSTRUCTIONS ON YOUR CONTACT CEMENT NOT ALL CONTACT CEMENT IS CREATED EQUAL
3. USE GLOVES
Now that I am done yelling at you, I set up my contact cement station at the door of a garage on a piece of old wood. I taped down my soles so they wouldn't move when I painted on the glue and I sanded them so they would adhere better. Make sure you get the glue all the way to the edges. Once it is on allow it to dry until it is sticky but does not pull away with your (gloved) finger. Stick them together making sure to line them up carefully because there is no going back, smooth them out, lay another piece of scrap wood or something flat on top, and something heavy like a paint can and allow them to dry for a while. This is not totally necessary, they can be worked with immediately but I wanted to be safe, and I had other things to do in the meantime.
Step 6: A Mini Lock-Stitch Tutorial
I'm pretty sure that this is called a lock stitch, but do correct me if I am wrong.
First you want to fold over the top of the back straps so that they fit the cord you have through them. pull enough thread out of your Awl to go across the top of the strap and a little extra for tying. From here on out the photos do most of the talking; Poke the needle through the strap partway, and pull out the side of the thread that is not coming from the spool, thread the part of the tread that you pulled out through this loop, and pull the needle back down to secure, repeat this same process until you reach the end, tie a knot, and super glue it.
I tried my best but you may want to watch a YouTube video on this process before you go poking holes in your leather. We will use this stitch again so the straps are a good way to practice because they are a lot less leather and work to replace than the soles.
Step 7: Patterning Again
Mark about 5mm in from where the straps are and cut a hole in your pattern.
Step 8: Cutting Holes in the Sole
Mark your dried soles with the pattern, and cut holes for the straps. You will probably need to fiddle with this alot because you want the straps to fit snuggly.
Step 9: Fitting Straps
After you have cut your holes fit each strap to your foot again. Mark each strap on the inside where it fits and remove. Past this mark you want to "skive" the end of the strap, basically shave it to be gradually much thinner with an exacto blade. Do this with each strap. Because there are so many similar straps mark this skived edge with some sort of system that coordinates with your pattern so you know where each end of each strap goes.
Step 10: Finishing Bottom of Midsole
Skive the inside of the holes where the straps will sit so the leathers can blend together and be more flat to step on. You will also now want to rough up the bottom of the midsole for when you glue it. You need to do this before sewing so you don't tear up your stitches. I did this by making quick hashmarks with my exacto blade.
Step 11: Contact Cement Take 2
Triple check the fit of your straps before you glue. Apply contact cement to the inside of the straps and the sandal where they will sit, after it is tacky stick them together. Be careful of squeeze out in this step.
Step 12: Sew the Soles
After you have your straps glued in it is time to stitch all the way around the soles. This is the same stitch as with the straps, but a little different in the beginning and end because there are no edges. In your first stitch pull the end of the thread all the way through, with enough length to go all the way around the sandal and then tie. Then stitch all the way around, when you come to the end pull the needle down so you get the end of the thread out the bottom and tie a knot and glue.
Step 13: Contact Cement the Final Chapter
Contact Cement the shoe upper to the bottom sole, so that the shiny side of the sole is on the ground. Make sure you cover it completely because there will be no stitching holding these layers together. Press them firmly together. After this hammer the soles around the edges, contact cement holds better the more pressure that is applied so hammering around the edges makes them extra strong.
Step 14: Sanding
Next is sanding and this is a lot easier if you have access to a belt sander, but it can be done by hand with sandpaper on a dowel rod or a sanding block. First take your unused sole pattern and cut around the edge so it fits inside the straps and tape it in place to keep the insoles clean when you sand. I used the skinny end of a horizontal belt sander and I am satisfied with the edge this gave me, the edges can also be burnished or finished with wax if you wish you can find tutorials for that pretty easily. Edge smoothness is what stops the separate edges from catching and pulling apart, so the smoother the edges the stronger the shoe.
Step 15: Lace Um!
Cut enough of your lacing to go around your ankle and tie. Make a masking tape needle as shown and thread it through your straps.
Step 16: Done!
Happy crafting! Feel free to comment questions or advice.