It has been almost 3 months since I last had a chance to work on the harpsichord but I finally managed to find enough time to get the soundboard glued in.
Putting in the soundboard is a major milestone but, particularly with an Italian instrument, it also has a certain sense of finality about it. Once the soundboard is in the inner structure of the instrument is completely inaccessible and will, with any luck, never be seen again.
I pinned the bridge a few months ago but I double checked everything and found 2 or 3 pins that were not in quite the right place - they weren't far off but it's easier to fix them now rather than risking problems later.
I also had to spend some time making sure that the ribs on the underside of the soundboard fit perfectly in the small slots cut for them in the liners and finally I had to repair a small hairline crack in the soundboard.
Once all that was done I glued in the rose which comes from Gianluca Ceccarini and, finally, everything was ready.
Wooden blocks about 4.5" high are used to extend the reach of the F clamps down inside the case. As I discovered last time it is quite tricky trying to get 40 F clamps all lined up correctly in the short space of time that is available until the glue starts to set, so this time I went to a lot of trouble to make this as easy as possible. The wooden blocks have a slot cut in them so that they hook over the edge of the case which helps to keep them vertical - they also have a small groove cut into the outside edge of the block into which the bar of the F clamp fits and a circular hole on top into which the screw of the F clamp fits. This makes it very easy to get the clamps lined up correctly and keep them square.
There are 39 F clamps around the edge of the case and 9 C clamps in the gap between the soundboard and the wrestplank.
Total time from start to finish was just under 25 minutes - about 5 minutes to apply the glue to the soundboard and the liners and actually get the soundboard in place and then almost 20 minutes to get all of the clamps in place.
I left the clamps on for about 18 hours and then removed them.
So far everything looks good - there was just enough glue squeezed out around the edge of the soundboard to reassure me that I had used enough glue but not so much that cleaning it up will be a probelm.
Next tasks are to trim the soundboard perfectly flush with the edge of the gap and then fit the soundboard and wrestplank mouldings.
An ingenious clamping solution. Since I don't have a ceiling that I can jam go-bars against, I shall shameless rip off your idea. :D
ReplyDeleteYes, I was very please with how well those clamping blocks worked. The main reason for making them (and for most of the other clamping solutions that I used) was that I was working entirely on my own and needed to be able to get things clamped quickly and reliably with only one pair of hands available to do all of the work. Some of the more complex parts of the assembly would have been much easier with the help of one or two assistants.
DeleteBy the way, these blocks were partly inspired by a set of clamping blocks and wedges that are supplied with the kit and which are supposed to help with fitting the various moldings to the case. I found that the wedges were extremely useful for all sorts of things but that the blocks themselves were useless to me since using them to clamp anything appeared to require a minimum of four (and, preferably, five) hands ...
What kind of soundboard work did you do from when it arrived? Any further contour thinning, scraping, sanding, etc?
ReplyDeleteThe rose is beautiful. What material is it made of?
The soundboard was trimmed to size and sanded and scraped with a cabinet scraper before fitting the bridge and the ribs. No planing or thinning was recommended or done. The rose is, indeed, very beautiful - it is a 3 layer parchment rose after Zenti which I got from Gianluca Ceccarini - http://www.gianlucaceccarini.com/roseTastieraeng.htm
DeleteI will also usually be working alone, so the techniques you thought through will be of help to me. The cats and dogs don't seem to help much...
ReplyDeleteLooks like I can also use this as an excuse to get more Jorgensen clamps. I've had around 25 for decades and use them all the time. But it seems double that number would be in order.
I looked over Gianluca's site. Just - wow. I'll be in touch with him. I may even finally get around to making a vihuela just so I could install one of his roses.