We're back to keep track on the repairs of my other two Venezuelan Cuatros. You can recognize one of these because it's my latest build. Yes, my back up instrument suffered a fall because I'm a klutz when I don't sleep well. So, it needed to get on the worktable.
Frets, sanding, tricks to unglue something, there are some interesting things to see in this entry.
Let's jump right to it!
New Frets, New Life
Embla's frets were worn down. I didn't realized until it became two noticeable. When this happens, frets lose their curve, which is called crown. Once your frets lose this crown, notes don't come out of the instrument with a clean sound. It is a mess.
Last time we got the frets in place, but there's the extra step of working them to make them playable and comfortable. Plus, there's the safety idea too. So, here we are working on the ends. These parts are usually sharp since we just cut them and put them in place.
So, I don't have the block that's common among my fellow luthiers. It is a wood block that has a bevel and a file. It is used to both make the ends flush to the fretboard and then putting a bevel on the frets.
Then, it is a thing of making use of a lot of elbow grease and file each fret down to the fretboard side. We do this with care. It takes plenty of time. And of course, we need to use protection because if you think sand is dangerous for lungs, imagine metal dust. We keep using the file until we have worked on all the ends of each fret. That means both sides.
To finish this work, we use a sanding block to make sure the ends are flush. The final step is to use this block to put a bevel on the ends of the frets. For this, we try to keep the same angle until we have the desired results. The last bits of work is to make sure there is no sharpness in any part of this bevel.
Unglue it!
So, this is a look at the accident on the back up Cuatro. It fell to the ground and bounced. It was quite an event. It also cracked in other places but this down part was the worst.
When trying to unglue something, we need to have something in mind. Glue is stronger than wood. So we need to make sure we work with precision. I tried to separate the back from the sides without any help and it didn't go well. Not that something broke more, but the bond was two strong. This is something to pat my back. But I know the trick to do this work.
Glues used for instrument are water resistant, but not heatproof. Not like the bonds will be undone by weather conditions. However, it is the usual thing since repairs are usually in mind. So, we need to break the bond with heat. I don't own a heat gun because that a very niche tool. Nevertheless, an iron works just fine. As a measure of extra protection, we can use a wet cloth.
We charge the iron with water. Plug it in. Set it to high heat. Then, when it gets hot, we put the cloth of top of the instrument and start ironing it. This heat will break the bond of glue and wood. We have to keep in mind we don't want to break all the bonds of glue, just the one for the back. And some of it work break, you'll see in photos.
Now, once we have started to do this work, we can take pauses between ironing and using an exacto knife to finish breaking the glue bond. Bit by bit, we alternate between knife and iron. This ends up helping us on the task and preventing breaking something.
Howver, as you ca see the back wasn't only broken on this part, it broke on some other places and that's why you can see it in pieces.
And this is how work goes so far!
Next time, we'll start gluing a new back on this instrument and start with the finish on Embla.
Thanks for reading!
Fotos/Photos 📷: taken by me (Redmi Note 13)
Portada/Thumbnail 🖼️: by me, created with Canva.
Edición/Editing 🎬: by me, made with Adobe Photoshop Lightroom.
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