Welcome back to another entry about this mandolin build. Last time, we did a lot of work in thicknessing the sides, bending them and finally gluing them in place. Today, we are closing this instrument so it can be taken out of the mould. That means we are adding all the reinforcements that go inside the mandolin.
Let's get to it!
Kerfing
We add two kinds of kerfing to the instruments. The one that goes between sound board and sides is the broken type. That just means it comes in pieces and we add it one by one. These pieces are usually made way before we start any project. Last time we made some of these we had taken the consideration of making as much of them as possible to avoid having to make them for future projects. The jar is almost empty but it could very much still complete two more instruments.
We add the kerfing one by one adding enough glue to see a spread when they are pressed against the surface. And we repeat the process until the whole area between the sound board and sides is covered.
While that glues up, we move on to the other kerfing. This type is a single strip of wood that goes between the sides and the back. In this case, we are only going to see it be glued on the sides since the back goes at the end. We work on the thickness of the strips of cedar until we can bend them. Here it is not shown, but the pieces are soaked in water to prevent any burnt marks. It also helps with the flexibility of the wood. We bend and check we are on the right track with the help of the sides. When we are ready, we let them dry clamped to the sides using wooden pegs.
To finish this step, we cut the kerfing to the length required and then make the final adjustments. Then we apply glue and use more wooden pegs to clamp it to the sides. We let it rest until the glue has dried properly.
Extra reinforcements
The last reinforcements we are placing are the vertical ones. These go across the sides to strengthen them in key spots. These are the usual places were an instrument could receive a bump. The task is simple. We cut some pieces of wood to the length required between the kerfings and then glue the piece of wood in that place using a clamp to hold it while the glue dries. Rinse and repeat and we are done.
While the other part glues, we are working on the last bits of the back to glue it in place. These bits are cutting the label to place it in its spot. Then removing any extra material from the bars that reinforce the back. This is to make it fit between the kerfing and also that the piece gets into the build like a tight lid.
To make sure this last part is done properly, we need to remove material from the sides until we make it as close as possible to the kerfing. Then we sand the whole surface. We use the back to check if there are any high spots. If there are some, we use the sanding block to fix them.
Assembled!
To finish the tasks for the day, we are up to the closing stage of the instrument. Once we have completed all the previous steps, we can apply glue to the kerfing and sides to finally put the back in place. Before we do it, we need to make sure to remove the bolt that holds the instrument to the mould. This can be done afterwards as well, but it will be even more difficult since the sound hole is an oval.
Once we have checked everything is ok, we can put the back in place and use the means at out hand to make it bend to the shape of the instrument. We already have the round shape on it, but it will need some pressure to stay in place. When we are sure the back is in full contact with the rest of the build, we can let it rest.
When it has glued properly, we can remove the clamps and weights to check if everything is ok. And we can do something extra by using the router to remove the extra material from the borders of both faces of the instrument. Thus having 50% of the work on the build complete and having the other half to go!
On the next entry, we will start working on the extra steps to make the parts that are missing from the build. All getting us closer to the end of the project. Thanks 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 |
| 7 | End Block and Sides |
Photos 📷: Redmi Note 13
Thumbnail 🖼️: Canva.
Editing 🎬:Adobe Photoshop Lightroom.
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