Welcome back to another entry on this Mandolin Build. Last time we saw this project, we had just finished making the back giving it its round shape and adding the bars. There is a long way to go to finish the whole instrument. Today, we are starting the process of assembly on the mould.
Let's get to it!
End Block
The end block in this instrument needs to have a certain slope. The idea is making it fit the round shape of the sound board. However, we need to give it a certain inclination towards the outside of the instrument. The reason behind this is can be found in the fact that the sound board will have also an inclination that will give it a longitudinal roundness. If the end block were to be put straight, once the sound board fits in the mould, the block would get the end block towards the inside of the instrument. And this would cause many problems.
If we keep the outside inclination, once the sound board is put in the mould the end block will have the straightness needed to keep everything in place. The whole thing is made with a lot of trial and error. We need to sand it or use a hand plane to create the slope and the round part. So the challenge is to have both shapes in place. The make sure the inclination is the right one, we can press the block on its place until we see the alignment of the block serves its purpose.
We can also use some contraption to make sure the glue up is proper. The idea is using a piece of wood and some screws to make sure the end block gets glued in place. The rest of the job is using another piece of wood and using it to hold the neck and sound board assembly against the mould.
Side thickness
Now we are going to start removing material from the sides until we achieve the desires thickness. The first step is using the hand plane to remove material from both sides. The idea is to remove the cutting disc marks from both faces of the sides.
The last step to finish the thicknessing is switching to the card scraper to get closer to the results. We can also use some sandpaper to get even closer. We know we are in the right track when we can wobble the sides and they give us some kind of spring sound. It is also a nice idea to bend the sides a bit to understand their flexibility. However, we need to make sure we do not overdo our bending since we could listen to some cracking. That could end in breaking the sides and that is something we do not want.
Bending
This is one of the best parts of the whole project. When we are trying to bend the sides, having them get into the shape we want is one of the best feelings. Especially when there is no cracking sound. We start by soaking the sides in water to hydrate the fibers and prevent any burning marks.
Once the wood has soaked for a long time, we turn on the bender. We need to wait until we can throw some water on the bender and see the Leinderfrost effect. That means that the water drops do not evaporate but dance on top of the can. When this is that hot, we can bend the sides without too much effort. Using some other pieces of wood to avoid touching the wood is also important. We can get burnt easily once the water dries during the bending process. We can use the mould and the lines to make sure we are bending the right curves.
When the sides match all the lines, we are done. We could also fix any other things by using water and bending a bit more.
The last thing we are doing is using the lines to cut the sides to the length we need. And we also need to sand them to make them fit the curve of the sound board. There is not too much curve around the borders, but we need to make sure no light comes between the sound board and the sides. However, we are also using some pressure downside to make sure the glue up works. Also we need to make sure the end-block glue up works well too. And then we let this rest and get ready for the next step.
On the next entry, we will go over the reinforcements that go in the in side of the instruments and get closer to put the lid on the mandolin. Thanks a lot for reading! See you next time!
| Number | Entry |
|---|---|
| 1 | The First Mandolin |
| 2 | Starting a Neck |
| 3 | The Heel |
| 4 | Headstock and Template |
| 5 | Neck, Sound Board and Mould |
| 6 | Round Back |
Photos 📷: Redmi Note 13
Thumbnail 🖼️: Canva.
Editing 🎬:Adobe Photoshop Lightroom.
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