According to the method of making the piano board first and then assembling it, both the inside and outside of the panel and backboard have been processed, leaving only the edges of the piano and its connection with the groove unfinished. But this can be completed before or after the combination of the qin, and now we will introduce the production of the qin edge before the combination of the qin.

Edge trimming of piano board

Firstly, check if the panel, back panel, and side panel frame can be well matched together. If there are no issues with the matching, the next step is to trim the edges of the piano. First, trim the edge of the qin (skirt) along the final side panel diagram to the same width, with the skirt at the corner of the qin being narrower. The skirt width of the violin is 3 millimeters, and the edge width at the corner is 2 millimeters. The width of the viola skirt is 3.2 millimeters, and the corners are 2.2 millimeters. The cello skirt is 4 millimeters wide and 2.8 millimeters at the corners.

2. When installing the side line, the piano edge with margin is trimmed to the same width according to the side plate block diagram that has not been demoulded, and the side line slot is made based on it. Therefore, if the side plate frame has been adjusted to narrow the width of the piano edge after demoulding, it is obvious that the distance between each side line and the skirt edge will be somewhat different. Fortunately, the difference is not too significant, and the edges are curved, which is generally not easily noticeable to the naked eye. But there is a slight difference in the width of the skirt hem, which can be noticed by picking up the qin and observing it carefully. The Kremona school only trimmed and made the edges of the qin after it was combined, but they made both the edges and skirt very perfect. However, the positioning of the sound hole is based on the position of the side plate before demolding. Once the position of the side plate is adjusted, there may be some differences in the distance between the sound hole and the edge line.

After adjusting the width of the skirt edge, the next step is to round the piano edge. The edge of the qin is also a part that reflects the craftsmanship level of the maker. Trained makers, although with different styles, can all achieve beautiful shapes and precise sizes. It is more convenient to round the corners of the bottom surface of the qin board before combining it. If you want to round the edges of the qin board after combining it, you can first cut the edges of the qin board at the bottom surface into a beveled edge.

4. Since the bottom surface of the piano board is the reference surface, if uneven thickness of the edges is found at this time, the top of the edges can be planed to make the edges reach the specified thickness and the surface smooth. Although the edges have been kept to the specified width in order to create ridges when trimming the surrounding grooves and edges, the width may vary depending on the amount of scraping off each part once it is flattened. Use a compass to re mark the position of the spine. The spine of the violin should be 2 millimeters away from the edge of the instrument, 2.2 millimeters for the viola, and 2.5 millimeters for the cello.

5. First, use a knife or file to trim the two edges on the outer edge of the piano into beveled edges, and then file multiple beveled edges between the upper and lower edges. Finally, use sandpaper to polish each beveled edge, making the edges smooth and rounded. Use a scraper or sandpaper block with a shape similar to the surrounding groove to connect the groove and ridge, making sure the contour of the ridge is clear, but not necessarily very sharp. This process relies entirely on the artist's artistic vision and manual skills to make the edges of the piano equally beautiful and precise.