Introduction: Wet Formed Leather Harmonica Case With 3d Printed Logo
I have had this harmonica since I was a wee lad (as you can see in the picture) I was recently going through some old boxes and I found it again. I decided that it was something worth protecting and decided I would make a leather sheath for it. I also decided that I wanted it to be a bit more than just a leather sheath so I decided to add an embossed logo.
Don't forget to check out the video at the top of the page and feel free to ask any questions in the comments below.
Below are links to tools and materials I used in this article. It is either the exact tool/supply or something very close.
Beginners leatherworking kit (includes needles, thread, slicker, stitching chisels, and more!)
Note: The amazon links in this article are affiliate links, meaning, at no additional cost to you, I may earn a commission if you click through and make a purchase.
Step 1: Design and Print Logo
I used fusion 360 to design the stamp. I first took a picture of the harmonica and imported it into fusion 360 as a canvas. I took the picture on top of my seal healing mat that way I could calibrate the image to be the correct size. I also reversed the image so that the stamp I made would be correct after embossing it.
I created a new sketch and traced out all of the letters using lines and arcs to get as close as possible. I created a bounding box that was a bit offset from all of the letters. This will form the base of the stamp.
I extruded the letters 3/64" up and extruded the base 3/32" down. The last step was to add a fillet on all of the edges to ensure that the fibers of the leather do not get cut when stamping.
I exported the model as an STL and printed it on my ender 3 pro.
If you don't have a 3d printer you can skip this step (and the next one).
I have included the stamp STL file incase you happen to have the same bluesband harmonica (they still sell them, check the link in the supplies section!)
Step 2: Emboss Logo Into Leather
I used 5-6oz veg tanned leather for this project. I first cut a piece that was larger than I needed (as it is always easier to trim later) and then wet it down with water. I placed the stamp in the middle and clamped it in place.
After waiting overnight I removed the clamps and now had an embossed "blues band" logo in the leather.
Step 3: Design and Print Form
Back to fusion 360 to design the mold for the case. I took the rough dimensions of the harmonica and created a stand in model for it. I then offset those dimensions and created a U shaped mold. The mold is 15/32" thick with a 3/32" gap between the harmonica and the mold.
The last thing I did was add a fillet on the inside edges to give it a rounded over appearance.
I exported the model as an STL and printed it on my Ender 3 pro.
If you don't have a 3d printer you could instead use three pieces of wood as the mold. Cut the pieces to size and attach them into the same U shape and you will have a perfect mold (and it would probably be faster to make!)
I have included the STL file for the mold for the harmonica, just in case you have the same harmonica as me (if you want one, they still sell them, check the supplies links at the top)
Step 4: Wet Form Leather Around Harmonica
I filled a bucket with an inch or two of water and submerged my piece of veg tanned leather. While the leather was soaking I covered the harmonica in plastic cling wrap. This will protect it from getting water/rusting.
I placed the leather over the harmonica and used my fingers to mold it to shape. After I got it close I placed the mold on top. I lightly clamped it in place (don't go too hard because you don't want to squish the bottom leather.)
After letting it sit for 24 hours I came back and was left with a perfect mold of the harmonica.
Step 5: Trim Formed Leather
I used the mold as a guide to trim the leather. I used an X-acto knife and tried to get it as straight as possible (as it will be a reference edge in a later step)
I also added a thumb-hole cut out. I roughly traced a circular object that was a bit bigger than my thumb. I again used my X-acto knife and cut the circle.
Step 6: Attach Back Piece
The back piece was made from some scrap leather. I traced the mold with a pencil. This gave me the outline where the contact cement needed to go. After applying contact cement to both sides I waited for it to dry and then attached it together.
After it was connected together I was able to add a thumb-hole cut out to the back piece. This way I could line it up perfectly with the top thumb-hole.
Step 7: Add Stitching Holes
Using a pair of wing dividers I marked out the location for the stitching holes. I then used my stitching chisels to add holes along the line.
Step 8: Trim and Treat Edge of Leather
I decided that the flat edges looked a bit too big, so I trimmed off some of the excess. I then sanded the edge smooth. Sanding leather causes it to mushroom, so I used a #2 edge bevel tool to remove the mushroomed leather.
All of the edges got a coating of gum tragacanth and I used my wooden slicker tool to burnish the edges.
Step 9: Stitch Pieces Together
To permanently attach the front and back piece (and to add a nice detail feature) I decided to stitch them together with a saddle stitch. Detailing how to saddle stitch is beyond the scope of this article. Instead you can go here and learn from Jessy Ratfink in her article: https://www.instructables.com/How-to-saddle-stitch-leather/
After I was done stitching I cut the ends off the thread. to ensure they didn't pull apart I melted them in place with a lighter.
Step 10: Add Protection
Protecting the leather is an important step, especially if you are going to be handling this piece a lot. I first added a coat of neatsfoot oil. I rubbed it in with a rag and then buffed off any excess. After it was dry to the touch I added a coating of carnuba creme and did the same, rub on and buff off.
Step 11: Enjoy!
Now it is time to enjoy your hard work. If you are like me, that means putting the harmonica in the sheath and never touching it again to protect the ears of those around you! lol. One day I will give this harmonica to my son and hopefully he will learn how to play it.
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If you make a leather sheath for your harmonica I would love to see it (especially if it's a blues band!)
Grand Prize in the