The depths are nicely rounded and the square shoulders of the type shanks show not at all, or only faintly.
* Such as clean. end evenly but slightly oiled original; well united. thoroughly seasoned, height, and the fount is rendered useless.
In all ordinary stereotyping work, some moisture remains in the mould. It is possible to make a fairly sharp cast in a mould which is quite wet. By using Wood's fusible metal,* which melt3 considerably under the boiling point of water - say between 60° and 70° C. - a very fairly good cast is obtained, the heat not being sufficient to convert the water into steam. This experiment is interesting, not only as showing a possible means of making a stereotype in a shorter period than the usual time - although the high price of bismuth tends to put it outside practical work - but also as illustrating a point of some importance, that, in the case of a mould not very thoroughly dried, the best result is obtained with the metal at as low a temperature as practicable, whereas in the case of a mould baked for a long time, the hotter the metal is, the better the result, provided it just stops short of burning the paper; so it is possible to have failures either from the metal being too hot or too cold. The use of French chalk on the face of the mould tends to minimise the mischief resulting from traces of moisture in the mould, but as it invariably makes the face of the cast a little rough, it should only be used when needed.
Another use of French chalk is when numerous casts are required from the same mould, as it tends to prevent adhesion between the cast and the mould. When a large number1 of casts are required from one mould, other precautions to be observed are to use- a well-cemented and ripened flong which is not too soft, to avoid making the mould too deep, and to beat with numerous gentle blows, rather than with a smaller number of heavy blows, as this tends to give a mould in which the depths are nicely rounded off, and do not follow the nearly vertical sides of the type face. Again, patches of old mould, or pieces of thin sheet metal, may be laid in the more considerable depths of the forme, so as to support the flong where subject to the greatest strain. Some stereotypers do this in the case of most ordinary work; while those who have a difficulty in beating the flong without shifting it, do the same in the case of all very open formes.
The question of damage to type during the process of stereotyping is one of some importance, and it mainly steps in when a high temperature is employed for drying. If the forme is very tightly locked up in the chase it may, in expanding and softening under the heat, become elongated, while, on the other hand, it may become shortened by the pressure of the drying-press. These two circumstances tend to make a newspaper fount become of unequal and rather dry flong; drying thoroughly in the press with occasional tightening up; long baking of the mould; non-use of French chalk; a suitable hard metal - say the tin alloy men-tioned - and this at as high a temperature as the mould will bear; and a considerable "head" and margin of metal in casting, the margin being of the full thickness of the gauges.
Let the formes be locked with only a moderate force, sufficient to secure safe lifting. With the enormous power at the operator's command, only a slight turn of the wrench produces enough pressure on the type to secure this end - which may be verified by experiment - and then loosen the formes as soon as they are placed on the hot stereotyping bed, so as to allow for expansion. When possible, lifting the formes at all should be dispensed with: they should be imposed and then slid along on a continuous bed or imposing surface right on to the moulding bed, so as to avoid all possibility of accident. With such convenience at command, there would be no necessity at all for excessively powerful locking apparatus, and the ordinary wooden quoin and side-stick would be found sufficient. We strongly advocate the insertion of wood furniture - say about two-line pica reglet - between the long side-stick and the type; for, in case of undue expansion of the type in the process of moulding for stereotyping, the wood would give way before the metal type, and the latter would therefore be preserved.
It is sometimes desirable to mould work, in case of a future demand; but this is not done so often as it might, because the printer does not care to take the trouble of sending the formes to the stereotyper. Now it is a very easy and inexpensive thing for any printer to mould his formes immediately they come from the machine, and to keep the moulds in case of future need. Take the formes of a 16-page publication; a set of light metal frames fit in the gutters so as to bring these up to the level of the face of the type. The pieces of flong - each corresponding to a page, with the necessary margin - may be rather over-dry than moist; with them you can mould a page at a time, and not many seconds are required for moulding each page, while as each mould is made it is lifted off and set aside. The formes need not even be washed, as the remaining ink does no harm in this case; and the moulds being removed at once, there would'be but little risk of adhesion, even if there were not a trace of ink on the type. The damp moulds are now laid between quires of rough paper, this being sufficient to keep them flat during the time of drying, which may be several days. When dry, they are stored away in bundles.
In casting from one of these moulds a few pieces of old mould are pasted into the hollows at the back, and the brown paper flap is pasted as usual on that edge which is to be the top, but the extra thickness of brown paper at the back is dispensed with. In some newspaper offices, it is the practice to take the moulds off some of the earlier pages while wet, and dry them separately. When the mould is removed wet, there is a contraction of about 1/130 linear.