At last the old glue having by degrees been got rid of, the outer moisture is absorbed by a gentle wiping of the cloth along the course of the joint.
The next movement is simply putting the plate away to dry. To attempt any glueing together of the parts while they are swollen with moisture would be to make matters worse than before, as the edges are too soft to bear interference, besides which, the sharpness of them is difficult to perceive while wet and semi-transparent.
We will now, after the time allowed for drying, see the work proceeding under the hands of the workman. After trying the parts, that is, bringing the separated edges together for seeing whether a fresh and clean join can be effected, some soft wood at hand is cut for the combined purposes of mould and cramp. The piece used is about nine inches long by about one in width and a quarter of an inch thick. Marking off on this thickness, and a trifle over the greatest width of the back, the lower part of which is to be inserted, wood is cut away to the depth of about a quarter of an inch; within this again a further cutting is made to fit the modelling or rise of the curve of the back. This will admit the plate loosely. On placing it within, the two halves are squeezed together by soft wood wedges of necessary size inserted between the edges of the plate and the wood cramp; if necessary, another wedge on one side or the other of the joint is placed for bringing both to a proper level. After trying this without glue, the pieces are removed, glue of good strength is put on the surfaces to be joined and the whole put in position again. The lower end of the joint near the purfling will require a little additional cramping together.
This part of the process is one of the very few instances where more than a couple of hands are of advantage, if not of actual necessity, the reason being that the two parts or halves of the back which have to be brought to an exact level must be held in position by two hands very firmly, while a cramp (with paper padding and cork between the teeth) is screwed rather tightly by another person. It is then as usual laid by to dry.
After a satisfactory time has elapsed, the wooden tie, mould or cramp, as we may call it, with its small wedges is removed, the metal screw cramp at the end is unfastened, the paper removed, and the joint is found to be much improved, if not quite up to the original state as when new. There is of course some superfluous glue to be cleared away, this having oozed out when the glue was first applied, there is also a portion of paper adhering where the screw cramp was attached over the border. This is done by wiping with a damp rag until it is clear, finishing with a dry one.
There is yet a little more attention necessary at times when the repairing of a back of the kind just described has been gone through. Backs of violins of a standard of excellence both high and low are not always as robust in their substance as might be desirable, so when a trifle weak there is more strain on the middle line or joint than when the wood is stout. In this case a few studs are advisable. On this detail of repairing nearly always resorted to by repairers, a few words will not be out of place. For the present we will only treat of the back. The size, disposition and shape of these is by no means an unimportant matter. At various times and places different sizes and shapes have been the fashion. Often apparently merely a matter of caprice, these strengthening discs have been used to such an extent, both in size and number, as to defeat the very object the restorer has had in view. No repairer would think it worth while to cramp or keep pressed down by any means the studs that he may think proper to place in position. To obviate this he uses very strong glue; if a good workman he will see that the course along which the studs are to lie is quite clean, a slight washing with a brush or sponge will set this right.
Now it follows as a matter of course that the surface of the part, owing to the modelling, is somewhat concave, and so as the studs are invariably cut from a flat strip of veneer, if they are very large, the glue in hardening and of course shrinking during the process will leave a hollow space in the middle, or maybe on one side, where the drying happens to commence. There will be thus a lessening of the strengthening by the stud, and sometimes a jarring of the loose parts, giving an immense amount of trouble in finding out the obscure seat of the nuisance when the instrument may be otherwise in good order.
There should be then a distinct limit to the size of any studs that experience and judgment may dictate as indispensable. Three-eighths of an inch square may be taken as the limit to which it is safe to go.
The studs should be cut from fairly stout veneer, and for the present purpose, that of the back, usually of sycamore, the same kind of wood is preferable to any other.
They should be trimmed so as not to require much if any finishing when attached and dried, as all trimming with edged tools afterwards is likely to be attended by occasional slips of the chisel.