October 25th, 2010
I've been working on fixing the break I designated B2, upper bout.
I've been working slowly, a stretch at a time starting from the top of the break and working down, gluing and inserting spruce shavings from the base bar, then when dry, trimming them down.
As with the major cracks, the finish will not be perfect and will invite further retouching in a final aesthetic touch up phase before applying the ground, but it already looks better than the conspicuous crack that would be there without some fill.
After shaving the above, I stopped and flipped the top in order to work on the back.
Here I'm doing much the same as on the top, except with perhaps a little less regard for aesthetic. Why do it at all? Just a sense that I would like some wood filling the crack rather than using just hide glue as filler.
Most of the crack was well behaved with regard to crack alignment, resting on the body which serves to orient somewhat. There is old hide glue on the top around the edges, so the top fits like a kind of lid, and everything finds its place.
The exception was the last stretch which was not level. It becomes so easily when squeezed in a clamp.
This stretch of crack is also the cleanest and best fitting, with a lot of potential for straight crack edge to crack edge contact. In light of these facts, I changed my procedure somewhat, and did a regular crack glueing with top off the body for all but a small stretch at the start which is sufficiently gaping that I will have no trouble fitting some shaving.
With a palette knife I cleared a little glue from the top of the crack for later shaving insertion, but as I've written, the crack is tightest here, and there isn't much depth even with the clearing, so we'll see how it goes.
November 3rd, 2010
I actually managed to fit some skinny, skinny shavings a little bit into the shallow area of the fine crack. Turned out not too bad, should have taken a picture after shaving it. With a little touching up, this break is not going to be nearly as apparent as one might think it should be given how ugly it was.
I went to do the lower break, but the piece sits not well at all. The rib here has become quite grossly distended relative to the plates, possibly as a consequence of the plate shrinking over its many decades in greater proportion to any shrinkage of the ribs.
I've decided that I'll fix the lower ribs before attempting to repair break B1.
I used a palette knife and hot water to very carefully remove the ribs from the bottom block. This makes for a better repair, since I was able to trim just the slightest bit from the end of the rib for a better fit, as well as making it easy to clamp the bottom block after brushing some hide glue into the little crack it had developed.
Here I've cut a block, lined it with cork, and added it to my smallest crack clamp to make a peg hole clamp for gluing the rib back to the bottom block.
Finally, the right rib is glued in place, held by quick clamps. I started with the right rib, as it was the least distended of the two. Next I will deal with the left.
November 10th, 2010
Left bottom rib is now glued. I trimmed perhaps as much as 4 mm from the rib. That doesn't sound like much, but it makes a big difference. Trimming alone, however, doesn't bring it back into the proper shape.
Here the rib was pushed in a bit with the long crack clamp used diagonally across the bottom. It was dry clamped over night.
This rib is quite plastic, it doesn't take much to reshape it. I also dry clamped using a new clamp made from two maple vertical bars joined by ribs top and bottom (sadly, forgot to take a picture).
When I did finally glue, I only had to do a very little reshaping, pushing the rib out slightly with this small maple pillar.
It will be some weeks before my next update, as I have to spend some time on another project.
December 20th, 2010
I returned from a work related trip beginning of December, and have been finishing up repairing the broken bouts.
Following the same strategy as before, glueing a bit at a time taking care to make sure both sides are level. I popped a bit of cedar shaving in gaps inviting it, but for the most part the fit was quite tight.
There are special purpose clamps for working with violins which are much better. Unfortunately not the in the budget, so I make do with what I have on hand.
The cleats still need to be trimmed, but the work I did in November has led to a regular position, so I am packing to move and squeezed for time. Everything goes into boxes. Hopefully they'll be unpacked and I'll be back to work not too long into January. At that time I'll worry about this:
While the lower part of the lower bout fits top and bottom, it appears as though it is too long above the lower hole of the f-hole. I could force it, but am not inclined to introduce that level of stress. Instead I'm thinking of cutting were I've placed the dotted line. Hopefully the amount removed by the saw will be sufficient to make the difference -- if not, then perhaps a little sanding.
That is all for today. The story will continue another day.
Back to home,
page 1 (intro),
page 2 (mapping cracks),
page 3 (shaving bass bar)
page 4 (crack repair),
page 5 (crack repair),
page 6 (back repair),
page 7 (patching and back repair),
page 8 (patching and back repair),
page 9 (patching and back repair)