glass art




GLAZIER'S MANUAL

In this part of the work, it is meant to be as practical as possible, and we shall therefore, without hesitation, sacrifice niceties of language, and all similar considerations, to brevity and perspicuity. Our great object here, as it has been throughout, is to convey our information in as distinct and intelligible a manner as possible.

Before proceeding to speak of glazing, the order in which its various processes present themselves naturally demands that we should say something of Putty. This important and indispensable article in the glazier's trade, is composed of whiting and linseed oil. Chalk is sometimes used instead of the former, but the expense and labour incurred in preparing it is so much greater, that it can be no object to the glazier to employ it; for although it is certainly cheaper in the first instance, it will not ultimately be found so. Besides, the glazier will find it almost impossible to free it so completely of the sand and silica, with which it abounds, as to render it fit for making good putty. These will remain in such abundance, as to endanger the safety of the glass in working it in; neither will the putty work Kindly or well.

Whiting being therefore, in every way, to be preferred, it must be thoroughly dried before the oil is added to it, otherwise the union will not be effected, or at least be very imperfect.

A kiln will dry a ton of whiting per day, at a very trifling expense of fuel,* and the kiln itself, with all its erections, will probably not cost more than fifty shillings. Every glazier, therefore, whose business is of any extent, ought to be provided with one of them. After the whiting has been thoroughly dried and prepared, it ought to be passed through a very fine sieve, and all the lumps and knots that remain pulverized with a three inch roller on a table; and then also passed through the sieve. Great care must be taken to keep the whiting free of sand and other extraneous substances; the former, in particular, is extremely injurious to putty.
When putty is to be made, put the proper quantity of oil into a tub or other open vessel, (the one half of an oil pipe answers extremely well for the purpose,) and gradually add the whiting, at the same time keeping the whole in motion, with a stout stick fashioned like an oar, until it becomes of a sufficient consistency to work by the hand on a board or table. Having been removed thither from the tub, it must be wrought up with dry whiting, until it is converted into a solid compact mass. When brought to this state, it ought to be put into a hollowed stone or mortar, and beat with a wooden mallet till it becomes soft and tenacious, when more whiting must be added, until it has attained a proper consistency.

It is considered that the putty is improved, if the whiting and oil, after being mixed, are allowed to remain for about twenty hours before being wrought up. After putty has been made, it should be firmly packed in a cask, from which it may be taken from time to time, as it is required. It ought not to be used for ten or twelve days after it is made, when its colour, from having at first been a dull yellow, will have changed to a whitish free stone, which renders it more suitable for most purposes, from its being of a less conspicuous tint.

After a lapse of six or eight weeks, the putty in the cask will become hard; but it is easily restored to its original softness, by being beat as before, and it is much improved by this second operation.

Putty is made in England in large quantities, and is ground in a mill in the same way as white lead; but this is no improvement, as it is generally overwrought in this method of preparation, and rendered so tough and tenacious, that it does not work well, and is entirely without that degree of pliability which putty ought to possess.

The glazier, therefore, will himself make a much more workable putty with his mortar and mallet, and fully as cheaply, by employing his apprentices in its manufacture at their leisure hours.

When putty of a superior degree of fineness, which will dry quickly, is required, add a little sugar of lead, or litharge; and if,an increase of strength be wanted, a little white lead.

We now proceed to GLAZING. To glaze well, neatly, and expeditiously, simple as the operation may appear, is an art not to be acquired in a day. On the contrary, several years of practice are necessary, before that degree of proficiency in it, which constitutes an efficient and expert glazier, is acquired.

When a glazier receives an order to glaze a house, the first thing he must do, of course, is to proceed to measure the work to be done. In doing this, he must take the full size of the panes, that enough may be left for stripping, so as to produce an accurate fit into the sashes. This fitting must be performed with great care and nicety, leaving about one thirty-second part of an inch of space on each side and end of the pane, between it and the check. In other words, the pane must fill the space appropriated for it, to within the thirty-second part of an inch, or thereabouts.

This space is left to provide for such occurrences such as us the wood swelling with moisture, or the building setting, in which cases the panes would be apt to crack.

When the panes have been fitted into the checks of the sashes in the manner spoken of, they must be removed, and the checks well bedded with beat putty. This done, the panes are again returned to their respective places, and gently pressed or lodged into the bedding, humouring the glass as it were, should it be bent or twisted, and taking care that there is no hard extraneous substance mingled with the putty, which might endanger, if not actually break the glass. When a pane is perfectly bedded, it lies quite firm, and does not spring from the putty; but when, either from a perverse bend or twist in the glass, or any other accidental cause, it happens that it cannot be made to go quite close to the check, the vacant space must be carefully and neatly filled upon the back puttying, otherwise the window will not be impervious to the weather, and will be very apt to fall into decay by the admission of moisture. It may not be superfluous to observe here, that the convex, or round side of the pane, where such a shape occurs, should be presented to the outside, and the concave or hollow to the inside. The reasons for recommending this disposition of such panes are so obvious that they need hardly be enumerated. It may, however, be stated generally, that, when thus placed, they resist the weather better than if the hollow sides were exposed to it.

After the pane has been bedded, the next process is the outside puttying. This putty should be kept in the fore cheek, about the thirty-second part of an inch below the level of the inside cheek, so as to allow the thin layer of paint which binds these two substances together, to join the putty and glass; and that it may not offend the eye by being seen from the inside; and that, when it is painted, the brush may not encroach on any visible part of the pane, leaving those ragged lines or marks which are so often seen from the inside on ill-finished windows, and which are so displeasing to the eye. This operation, and finishing the corners, are two nice points in the art, and therefore, when properly done, discover at once the neat-handed and skilful tradesman.

It is the opinion of some experienced glaziers, that the inside puttying, which is the next process, ought to be allowed to remain eight days before being finished off, while others, again, say that this should be immediately done. The experience of the writer inclines him to the former opinion. By standing over for some little time, the putty acquires a hardness which admits of a better and neater finish than when it is in the soft working state, and in this way also, the putty is not liable to shrink. Of course, this is only recommended in cases of extensive jobs. When only a few panes are done, it is better to finish them off at once, than subject the employers to the inconvenience of a second visit from the glazier for so trifling a purpose.

When the finishing does take place, however, the putty must be cut clean off with the putty knife, and on a level with the style of the astragals. Complete the work by cleaning the glass and.putty with a 000 duster brush, which removes all dust and loose putty from the pane, lightly and effectually.