Breaks, Corners, and Cornices.

TO boss up a corner out of a flat piece of lead, for the stand-up on each side to reach a height of 6 in., and to be of equal thickness all over, a surplus of lead equal to 6 in. by 6 in. must be got rid of. But to boss or work up a break for the sides to be of equal height, 6 in., lead just that size (6 in. by 6 in.) is wanted. When, therefore, these two pieces of work are near each other, as they often are, the surplus lead of the corner should be bossed into the want of the break, or as much of it as practicable.

Fig. 7. - Showing Triangular Vacancy in a Cut Break.

Fig. 8. - Showing a Square Vacancy in a Cut Break.

2. If instead of bossing up the break the lead were cut down the angle with a knife, and the sides turned up, there would be a triangular vacancy on each side of the line of the vertical angle of the break, as shown at a a, fig. 7. Or, if instead of cutting the lead down the line of the angle, it were cut through the stand-up part of one of the sides, parallel with the edge of the stand-up of the other side, and along the end of the latter, parallel to and on the line of the horizontal angle, there would be a vacancy 6 in. by 6 in., as shown at b, fig. 8.

Fig. 9. - Showing Lead for Bossing Up Break.

3. The lead for bossing into a break is drawn from an extra width of turn-up left for the purpose, as shown in figs. 9 and 10. Some prefer to boss the lead into the break from round about the top, g g g g, chiefly using a bossing-stick for the purpose. But this means a tedious bossing of from about an hour-and-a-half to three hours, depending upon the ability of the worker.

By pulling and curling or twisting round the ends a little at c c and e e, and pouching up the lead at the break at g g h, a large amount of lead can be drawn from the sides and worked in waves, with the side of the big mallet, to the break. And in this way, as well as drawing down lead from round about the top, g g, the break can be knocked up pretty quickly.

The lead should be pulled up hard at about g g with the left hand; and with the right hand, by a series of quick heavy blows with the side of the big mallet (the large end being kept chiefly outwards), lead should be gathered at about e e e, and driven round into the break. By repeating this process several times, on both sides of the break, where practicable, and by keeping hard at the work, to keep the lead warm by the friction from a quick succession of blows, it will soon be found that enough lead has been gathered round about the break, as shown in fig. 10, to complete it with a bossing-stick, working the lead down from d and e into the angle of the break, somewhat after the shape of a cocoa-nut, which gives a reserve of lead for working into the angle just before squaring up the sides. When completed, the lead in every part of the break should be left equal in thickness to any other part of the sheet.

Fig. 10. - Break partly Bossed Up.

To afford plenty of lead for bossing up a break, it is better to cut the piece of lead of which it is to be made much larger than the place it is to fit into, and to set it out for its position, and perform any other bossings upon it, after the break has been bossed up.

In drawing the lead from the sides, care must be taken not to weaken the lower part of the stand-up, or any part of the horizontal angles, or the bottom.

4. To boss up a corner 6 in. high out of 7 lbs. lead, means half-an-hour's hard labour for the plumber, even if he gets through it in that time, especially if the lead be at all hard; and though no great skill be required to accomplish it, much labour may be saved by intelligent bossing. Some men work hard and do not get up such a corner in an hour.

5. To avoid unnecessary bossing in working up a corner, it is better to cut off the surplus lead, the corner marked c in fig. 11. Having chalked in the lines on each side of the corner, to show the place of the turn-up, get a straightedge, or piece of quartering, and lay it down on the line chalked in, and so placed that you can just see the line all the way down; and then, with your mate kneeling upon the quartering at one end and you at the corner end, pull up the side - the stand-up - as hard as you can. Do the same with the other side or end, and cut in the horizontal angles with the hornbeam dresser, using the big hammer or big mallet to drive it in, and square up the sides. One blow ought to be enough for each dresser length; to repeat the blows only tends to weaken the lead in the angle, where it ought to be kept strong.

Fig. 11.

6. The horizontal angles next the corner may be just marked in with the edge of the dresser or chase-wedge, though the lead thickens more readily when free from tool-marks, and with a correct eye no such marks are necessary.

7. Begin the bossing upon the projecting or pouched corner, standing out like a donkey's ear, about 1 1/2 in. up from the bottom, as shown at A, fig. 12. Work in a little hollow with the thin edge of the bossing-stick, and boss the bulb or surplus lead downwards to thicken the bottom and stiffen the corner and horizontal angles, to prevent the former pulling over in the further bossing. Then drop the bossing-stick, and take two mallets and knock up the corner, keeping the lead circular all the time. When the stand-up is bossed up high enough, the corner should be squared up with two dressers, and finished off.

Fig. 12. - Showing Corner partly Bossed.

8. As the durability of lead coverings to cornices depends so much upon its freedom to expand and contract, the pieces of lead should never be put on in very long lengths; and instead of soldering the ends of the pieces together, especially when the weathering of the cornice is outwards, the ends should be seam-welted, or turned over rolls.

9. When a cornice is too wide for the rain to drain to the front, a channel, as shown at a, fig. 13, should be cut in the stone top, next the face of the wall, and the top of the cornice weathered back into it. "When the stone cornice is deep enough, shallow sinkings can be made where the rain-water is to be taken away, and the lead dressed down into them. The stone channel can often also be so worked that, when the cornices are of great length, a drip may be formed in them here and there. Where the stone is not thick enough to admit of this, the weathering from the edge of the channel should be outwards, and the edges of the lead on this part seam-welted, and the edges in the channel burned or soldered.

10. When the edge of the lead is left to sail over beyond the cornice, it is nearly always in need of dressing up, for it so frequently gets knocked about with ladders, etc.; nor is the edge of the top of the stone cornice so well protected from the weather as with a turned-down edge.

11. When the edge of the lead top is turned down over the edge of the fillet of the stone or wood cornice, great care should be taken to carry it down below the bottom edge of the fillet for the rain to run off, or drain away, clear of the mouldings. When the edge of the lead is only just turned round the top edge of the fillet, or when it is dressed round under the bottom edge and into the cyma, the washings of the top run and drain round upon the lead into the mouldings, and down over the walls, leaving dirty stains behind them.

12. The lead at the back of the cornice should be made to stand up against the face of the wall, just high enough to protect the lower joints of the wall from rain splashes, as shown at a, fig. 13. A separate lead cover-flashing

Fig. 13. - Section showing Lead Covering to a Stone Cornice.

(to give better freedom to the lead on the cornice) should be fixed to the stand-up, as shown at c, where practicable. 13. To keep the lead top in position, and to prevent the wind blowing it up, a few inches back from the front edge, and at intervals of about every 2, 3, or 4 ft., according to circumstances, lead dowels should be run into the stone cornice, with hemispherical heads over them (fig. 13) to keep down the lead. These lead dowel-dots are easily ran into the stone with molten lead, and formed by using the tool shown in fig. 14. Around the aperture in the lead top for pouring the lead through to the dowel, a little necking should be bossed up to keep out the rain-water, in case the burning should not be perfect when the dot is run in.

Fig. 14. - Dot-mould.