Stained Glass Work: A text-book for students and workers in glass

In short, the thing is a niggling and botching sort of process to my mind, and I hope that the above description is sufficiently life-like to show that I have really given it a good trial myself—with, as a result, the conclusion certainly strongly borne home to me, that the delight of having one's work unchanged by the fire is too dearly purchased at the cost of it.

How to get the greatest degree of Strength into your Painting without Danger.—Short of using a needle then, and a matt that will only yield to that instrument, I would advise, if you want the work strong, that you should paint the matt so that it will just yield, and only just, and that with difficulty, to the scrub; and, before you use this tool, just pass the finger, lightly, backwards and forwards over the matted surface. This will take out a shimmer of light here and there, according to the inequalities of the texture in the glass itself; the first touches of the scrub will not then look so startling and hard as if taken out of the dead, even matt; and also this rubbing of the finger across the surface seems to make the matt yield more easily to the tool. The dust remaining on the surface perhaps helps this; anyhow, this is as far as you can go on the side of strength in the work. You can of course "back" the work, that is, paint on the back as well as the front—a mere film at the back; but this is a method of a rather doubtful nature. The pigment on the back does not fire equally well with that on the front, and when the window is in its place, that side will be, you must bear in mind, exposed to the weather.

I have spoken incidentally of rubbing the glass with the finger as a part of painting; but the practice can be carried further and used more generally than I have yet said: the little "pits" and markings on the surface of the glass, which I mentioned when I spoke of the "right and wrong sides" of the material, can be drawn into the service of the window sometimes with very happy effect. Being treated with matt and then rubbed with the finger, they often produce very charming varieties of texture on the glass, which the painter will find many ways of making useful.

Of the Second Painting of Glass after it has been Fired.—So far we have only spoken of the appearance of work after its first fire, and its influence upon choice of method for first painting; but there is of course the resource which is the proper subject of this chapter, namely, the second painting.

Very small work can be done with one fire; but only very skilful painters can get work, on any large scale, strong enough for one fire to serve, and that only with the use of backing. Of course if very faint tones of shadow satisfy you, the work can be done with one fire; but if it is well fired it must almost of necessity be pale. Some people like it so—it is a matter of taste, and there can be no pronouncement made about it; but if you wish your work to look strong in light and shade—stronger than one painting will make it—I advise you, when the work comes back from the fire and is waxed up for the second time (which, in any case, it assuredly should be, if only for your judgment upon it), to proceed as follows.

First, with a tracing-brush, go over all the lines and outlined shadows that seem too weak, and then, when these touches are quite dry, pass a thin matt over the whole, and with stippling-brushes of various sizes, stipple it nearly all away while wet. You will only have about five minutes in which to deal with any one piece of glass in this way, and in the case of a head, for example, it needs a skilful hand to complete it in that short space of time. The best plan is to make several "shots" at it; if you do not hit the mark the first time, you may the second or the third. I said "stipple it nearly all away"; but the amount left must be a matter of taste; nevertheless, you must note that if you do not remove enough to make the work look "silvery," it is in danger of looking "muddy." All the ordinary resources of the painter's art may be brought in here: retouching into the half-dry second matt, dabbing with the finger—in short, all that might be done if the thing were a water-colour or an oil-painting; but it is quite useless to attempt to describe these deftnesses of hand in words: you may use any and every method of modifying the light and shade that occurs to you.

CHAPTER IX

Of Staining and Aciding—Yellow Stain—Aciding—Caution required in Use—Remedy for Burning—Uses of Aciding—Other Resources of Stained-Glass Work.

Yellow stain, or silver stain as some call it, is made in various ways from silver—chloride, sulphate, and nitrate, I understand, are all used. The stain is laid on exactly like the pigment, but at the back of the glass. It does not work very smoothly, and some painters like to mix it with Venice turpentine instead of water to get rid of this defect; whichever you use, keep a separate set of tools and a separate palette for it, and always keep them clean and the stain fresh mixed. Also you should not fire it with so strong a heat, and therefore, of course, you should never fire pigment and stain in the same batch in the kiln; otherwise the stain will probably go much hotter in colour than you wish, or will get muddy, or will "metal" as painters call it—that is, get a horny, burnt-sienna look instead of a clear yellow.

How to Etch the Flash off a Flashed Glass with Acid.—There is only one more process, having to do with painting, which I shall describe, and that is "aciding." By this process you can etch the flash off the flashed glasses where you like. The process is the same as etching—you "stop-out" the parts that you wish to remain, just as in etching; but instead of putting the stopping material over the whole bit of glass and then scratching it off, as you do in copper-plate etching, it is better for the most part to paint the stopping on where you want it, and this is conveniently done with Brunswick black, thinned down with turpentine; if you add a little red lead to it, it does no harm. You then treat it to a bath of fluoric acid diluted with water and placed in a leaden pan; or, if it is only a touch you want, you can get it off with a mop of cotton-wool on a stick, dipped in the undiluted acid; but be careful of the fumes, for they are very acrid and disagreeable to the eyes and nose; take care also not to get the acid on your finger-ends or nails, especially into cuts or sore places. For protection, india-rubber finger-stalls for finger and thumb are very good, and you can get these at any shop where photographic materials are sold. If you do get any of the acid on to your hands or into a cut, wash them with diluted carbonate of soda or diluted ammonia. The acid must be kept in a gutta-percha bottle.

When the aciding is done, as far as you want it, the glass must be thoroughly rinsed in several waters; do not leave any acid remaining, or it will continue to act upon the glass. You must also be careful not to use this process in the neighbourhood of any painted work, or, in short, in the neighbourhood of any glass that is of consequence, the fumes from the acid acting very strongly and very rapidly. This process, of course, may be used in many ways: you can, by it, acid out a diaper pattern, red upon white, white upon red; and blue may be treated in the same fashion; the white lights upon steel armour, for instance, may be obtained in this way with very telling effect, getting indeed the beautiful combination of steely blue with warm brown which we admire so in Burne-Jones cartoons; for the brown of the pigment will not show warm on the blue, but will do so directly it passes on to the white of the acided parts. This is the last process I need describe; the many little special refinements to be got by playing games with the lead lines; by thickening and thinning them; by doubling glass, to get depth and intensity, or to blend new tints;—these and such like are the things that any artist who does his own work and practises his own craft can find out, and ought to find out, and is bound to find out, for himself—they are the legitimate reward of the hand and heart labour spent, as a craftsman spends them, upon the material. Suffice it to say that in spite of the great skill which has been employed upon stained-glass, ancient and modern, and employed in enormous amount; and in spite of the great and beautiful results achieved; we may yet look upon stained-glass as an art in which there are still new provinces to explore—walking upon the old paths, guided by the old landmarks, but gathering new flowers by the way.

We must now, then, turn our attention to the mechanical processes by which the stained-glass window is finished off.

CHAPTER X

Leading-Up and Fixing—Setting out the Bench—Relation of Leading to mode of Fixing in the Stone—Process of Fixing—Leading-Up Resumed—Straightening the Lead—The "Lathykin"—The Cutting-Knife—The Nails—The Stopping-Knife—Knocking Up.

You first place your cut-line, face upward, upon the bench, and pin it down there. You next cut two "straight-edges" of wood, one to go along the base line of the section you mean to lead up, and the other along the side that lies next to you on the bench as you stand at work; for you always work from one side, as you will soon see. And it is important that you should get these straight-edges at a true right angle, testing them carefully with the set-square. Fig. 46 represents a bench set out for leading-up.

You must now build the glass together, as a child puts together his puzzle-map, one bit at a time, working from the base corner that is opposite your left hand.

But first of all you must place a strip of extra wide and flat lead close against each of your straight-edges, so that the core of the lead corresponds with the outside line of your work.

Fig. 46.

It will be right here to explain what relation the extreme outside measurement of your work should bear to the daylight sizes of the openings that it has to fill. I think we may say that, whatever the "mouldings" may be on the stone, there is always a flat piece at exact right angles to the face of the wall in which the window stands, and it is in this flat piece that the groove is cut to receive the glass (fig. 47).

Fig. 47.

Now, as the glazed light has to fill the daylight opening, there must obviously be a piece beyond the "daylight" size to go into the stone. By slipping the glazed light in sideways, and even, in large lights, by bending it slightly into a bow, you can just get into the stone a light an inch, or nearly so, wider than the opening; but the best way is to use an extra wide lead on the outside of your light, and bend back the outside leaf of it both front and back so that they stand at right angles to the surface of the glass (fig. 48). By this means you can reduce the size of the panel by almost 1/4 of an inch on each side; you can push the panel then, without either bending or slanting it much, up to its groove; and, putting one side as far as it will go into the groove, you can bend back again into their former place the two leaves of the lead on the opposite side; and when you have done that slide them as far as they will go into their groove, and do the same by the opposite pair. You will then have the panel in its groove, with about 1/4 of an inch to hold by and 1/4 of an inch of lead showing. Some people fancy an objection to this; perhaps in very small windows it might look better to have the glass "flush" with the stone; but for myself I like to see a little showing of that outside lead, on to which so many of the leads that cross the glass are fastened. Anyway you must bear the circumstance in mind in fixing down your straight-edges to start glazing the work; and that is why I have made this digression by mentioning now something that properly belongs to fixing.

Fig. 48.

Now before beginning to glaze you must stretch and straighten the lead; and this is done as follows (fig. 49—Frontispiece (#x1_x_1_i46)).

Hold the "calm" of lead in your left hand, and run the finger and thumb of your right hand down the lead so as to get the core all one way and not at all twisted: then, holding one end firmly under your right foot, take tight hold of the other end with your pliers, and pull with nearly all your force in the direction of your right shoulder. Take care not to pull in the direction of your face; for if you do, and the lead breaks, you will break some of your features also. It is very important to be careful that the lead is truly straight and not askew, otherwise, when you use it in leading, the glass will never keep flat. The next operation is to open the lead with a piece of hard wood, such as boxwood or lignum-vitæ (fig. 50), made to your fancy for the purpose, but something like the diagram, which glaziers call a "lathykin" (as I understand it). For cutting the lead you must have a thin knife of good steel. Some use an old dinner-knife, some a palette-knife cut down—either square across the blade or at an angle—it is a matter of taste (fig. 51).

Fig. 50.

Fig. 51.

Having laid down your leads A and B (fig. 52), put in the corner piece of glass (No. 1); two of its sides will then be covered, leaving one uncovered. Take a strip of lead and bend it round the uncovered edge, and cut it off at D, so that the end fits close and true against the core of lead A. And you must take notice to cut with a perfectly vertical cut, otherwise one side will fit close and the other will leave a gap.

Fig. 52.

In fig. 53 A represents a good joint, B a bad one. Bend it round and cut it off similarly at E. Common sense will tell you that you must get the angle correct by marking it with a slight incision of the knife in its place before you take it on to the bench for the final cut.

Slip it in, and push it in nice and tight, and put in piece No. 2.

Fig. 53.

But now look at your cut-line. Do you see that the inner edges of pieces 2, 3, and 4 all run in a fairly smooth curve, along which a continuous piece of lead will bend quite easily? Leave, then, that edge, and put in, first, the leads which divide No. 2 from No. 3, and No. 3 from No. 4. Now don't forget! the long lead has to come along the inside edges of all three; so the leaf of it will overlap those three edges nearly 1/8 of an inch (supposing you are using lead of 1/4 inch dimension). You must therefore cut the two little bits we are now busy upon 1/8 of an inch short of the top edge of the glass (fig. 54), for the inside leads only meet each other; it is only the outside lead that overlaps.

Fig. 54.

How the Loose Glass is held in its place while Leading.—This is done with nails driven into the glazing table, close up against the edge of the lead; and the best of all for the purpose are bootmakers' "lasting nails"; therefore no more need be said about the matter; "use no other" (fig. 55).

Fig. 55.

And you tap them in with two or three sharp taps; not of a hammer, for you do not want to waste time taking up a fresh tool, but with the end of your leading-knife which is called a "stopping-knife" (fig. 56), and which lead workers generally make for themselves out of an oyster-knife, by bending the blade to a convenient working angle for manipulating the lead, and graving out lines in the lower part of the handle, into which they run solder, terminating it in a solid lump at the butt-end which forms an excellent substitute for a hammer.

Fig. 56.

Now as soon as you have got the bits 1, 2, 3, 4 in their places, with the leads F, G and H, I between them, you can take out the nails along the line K, F, H, M, one by one as you come to them, starting from K; and put along that line one lead enclosing the whole lot, replacing the nails outside it to keep all firm as you work; and you must note that you should look out for opportunities to do this always, whenever there is a long line of the cut-line without any abrupt corners in it. You will thus save yourself the cutting (and afterwards the soldering) of unnecessary joints; for it is always good to save labour where you can without harm to the work; and in this case the work is all the better for it.

Now, when you have thus continued the leading all the way across the panel, put on the other outside lead, and so work on to a finish.

When the opposite, outside lead is put on, remove the nails and take another straight-edge and put it against the lead, and "knock it up" by hitting the straight-edge until you get it to the exact size; at the same time taking your set-square and testing the corners to see that all is at right angles.

Leave now the panel in its place, with the straight-edges still enclosing it, and solder off the joints.

CHAPTER XI

Soldering—Handling the Leaded Panel—Cementing—Recipe for Cement—The Brush—Division of Long Lights into Sections—How Joined when Fixed—Banding—Fixing—Chipping out the Old Glazing—Inserting the New and Cementing.

If the leads have got tarnished you may brush them over with the wire brush (fig. 57), which glaziers call a "scratch-card"; but this is a wretched business and need never be resorted to if you work with good lead and work "fresh and fresh," and finish as you go, not letting the work lie about and get stale. Take an old-fashioned tallow "dip" candle, and put a little patch of the grease over each joint, either by rubbing the candle itself on it, or by melting some of it in a saucepan and applying it with a brush. Then take your soldering-iron (fig. 58) and get it to the proper heat, which you must learn by practice, and proceed to "tin" it by rubbing it on a sheet of tin with a little solder on it, and also some resin and a little glass-dust, until the "bit" (which is of copper) has a bright tin face. Then, holding the stick of solder in the left hand, put the end of it down close to the joint you wish to solder, and put the end of the iron against it, "biting off" as it were, but really melting off, a little bit, which will form a liquid drop upon the joint. Spread this drop so as to seal up the joint nice and smooth and even, and the thing is done. Repeat with all the joints; then turn the panel over and do the opposite side.

Fig. 57.

Fig. 58.

How to Handle Leaded Lights.—I said "turn the panel over." But that brings to mind a caution that you need about the handling of leaded lights. You must not—as I once saw a man do—start to hold them as a waiter does a tray. You must note that thin glass in the sheet and also leaded lights, especially before cementing, are not rigid, and cannot be handled as if they were panels of wood; you must take care, when carrying them, or when they lean against the wall, to keep them as nearly upright as they will safely stand, and the inside one leaning against a board, and not bearing its own weight. And in laying them on the bench or in lifting them off it, you must first place them so that the middle line of them corresponds with the edge of the bench, or table, and then turn them on that as an axis, quickly, so that they do not bear their own weight longer than necessary (figs. 59 and 60).

How to Cement a Leaded Light.—The next process is the cementing of the light so as to fill up the grooves of the lead and make all weather-proof. This is done with a mixture composed as follows:—Whitening, 2/3 to plaster of Paris 1/3; add a mixture of equal quantities of boiled linseed-oil and spirit of turpentine to make a paste about as thick as treacle. Add a little red lead to help to harden it, some patent dryer to cause it to dry, and lamp-black to colour.

This must be put in plenty on to the surface of the panel and well scrubbed into the joints with a hard fibre brush; an ordinary coarse "grass brush" or "bass brush," with wooden back, as sold for scrubbing brushes at the oil shops, used in all directions so as to rub the stuff into every joint.

But you must note that if you have "plated" (i.e. doubled) any of the glass you must, before cementing, putty those places. Otherwise the cement may probably run in between the two, producing blotches which you have no means of reaching in order to remove them.