this is my first post on Maestronet, although I have enjoyed following many discussions.
I'm making a new cello for a customer and I've just completed the varnishing process. When I went to string it up, I realized that the projection had dramatically changed from 80mm to 92mm.
As I do for all my instruments, before starting to varnish, I set up the cello and had it played for a week in the white. As everything was fine I removed the whole set up, including the fingerboard and post and began the varnishing process. It took almost two months and half of the time it was under UV light where I kept the cello humidified. Throughout the two months I had issues with some persistent open seams which I attributed to heat in the UV cabinet.
Since I discovered the projection problem I removed the front for a thorough inspection and found the front arching quite distorted. All the corners, specially on the treble side, curled up and the cross arching had flattened, causing the f-hole wings to raise above the central area. I measured the arching heights both top and back and found that they had dropped by 3-4 millimiters. Since then I clamped the front onto the ribs to keep it flat as well as setting the old post, which I had to cut down a couple of millimiters in order to stand it up. In the last 5 days I've managed to gradually pull the post to its correct position and that has helped the projection to go down by 5mm, so that it is now 87mm.
I was told by the supplier that the wood was seasoned and ready to be used.
I haven't glued the top back yet and am wondering if this has happened to anyone here. Any suggestions would be most welcome!