When well hardened, this mould is lifted off; it comes away easily, showing a perfect facsimile in reverse of the back of the violin. This is carefully wiped, and any small specks of plaster that may be adhering are picked off.
The mould has now to be dried, as it would otherwise—from the large amount of moisture within it—undo the back, or any cracks that may have been glued up.
Placing in a moderately warm oven is as good a method as any, the natural drying by open air, even in sunny weather, being a long process.
After being tested and found to contain no moisture whatever, the mould is placed upon a bench, and the surface which has been in contact with the curved form of the back receives a slight oiling with a brush. This will prevent as much as possible injury to the varnished surface of the violin when placed in it. This may be further helped by a sheet of soft paper or soft cotton being placed between, when the back of the violin is laid in the mould.
Before proceeding further, there will necessarily be the preparations made in connection with the piece of veneer that is to be glued to the back.
In order that this may be as equally as possible pressed into the shape, there must be another mould made; this will be of some soft wood that will cut easily into shape, and be made to fit as near as can be to the back.
Next a layer or portion of cork about one-eighth of an inch thick, and large enough to cover the whole of the veneer, will be required. Some repairers would prefer india rubber or other yielding substances, which will fit into any unevenness while sustaining great pressure. This last will be caused by the press or large cramp, which must be very strong.
All the foregoing being ready to hand, the veneer being cut down to the amount required, perhaps to a pencilled line marked on it for width and length, it will be wetted; being of slight substance, it will soon absorb sufficient moisture to remain damp during and over the time the other preparations are made.
All being in readiness, the back being laid down accurately in its bed of hard plaster of Paris, the cloth or paper having been placed between, the cleansed and dried surface of the table is brushed over with the strong glue which, if the apartment is of sufficiently high temperature, will not coagulate or set, but give time for the brushing of glue on one side of the veneer. This is at once placed in position on the glued surface of the violin table; it is then covered with some thin, soft paper, the cake of cork or india rubber being laid over it. More carefully than all, the carved piece of wood that is to be pressed down must be exactly in its right place, and above this, other slices, so that the pressure may be distributed well, and not merely on one spot.
For this a goodly pile will be of advantage; to be quite scientific in its proportion, an imaginary line drawn from the central point of the pressure above to the outside or margin of the field of pressure at the lowest part, should not be at more than an angle of forty-five degrees.