Assuming that the glue is sufficient in quantity all round, it may be allowed to dry.
The upper table can now be tested for a good fit by laying it, and noticing whether the marginal projection over the ribs is regular or not; in some instances a little humouring or averaging of this projection has to be made, especially when the instrument is very old, and bears evidence of much trouble under the hands of repairers of different degrees of skill, experience and patience.
This being found satisfactory, a slight brushing of thin glue over the upper and lower end blocks will be enough before placing the table in position and cramping them down.
For the other parts the thin knife will be sufficient, wetted and worked between, the cramps being applied as before.
This way of closing up dispenses with all cause for hurry. The exact amount of glue can be calculated without danger of over-loading, and the next necessary opening for repairs can be effected without the least risk of damage to the margin of the upper table. By this method there is no occasion for wiping superfluous glue from underneath the over-lapping edge, as there will not be any perceptible, or, indeed, present, when tidily done.
Sufficient time being allowed for drying--a little longer for the end blocks, these being more hidden and slowly affected by the atmosphere--the cramps may be removed.
As a final process, the varnishing over the parts that have been repaired may be touched upon.
The success of this so much depends upon the natural talent of the operator for matching colours and mixing of different gums for obtaining as close as possible resemblance to the surrounding work, that any hard and fast rules concerning it cannot be laid down.
An alcoholic mixture is almost invariably used for the covering of raw repairs, time scarcely ever being available for the use of an oil varnish.
The most commonly used basis is a lac varnish. The ease with which this is dissolved and manipulated is a temptation to use it at times when it would be the least desirable for the imitation of old varnish. One great fault in connection with it is its retaining a glare on the surface when hardened, and the undesirable aspect is given of polished spots where repairs have been going on. There is only one way of counteracting this--by mixing other gums or resins that have less or but little glare when hard. Those of a very astringent quality should be avoided, as when dry their pulling power or contraction is very great, and a cracked surface not at all like the rich fused appearance of many of the old masters, but dry and uninteresting, will make itself too evident.