Woodwork Joints Part 10

[Ill.u.s.tration: Fig. 221.--Stop-bound Door.]

[Ill.u.s.tration: Fig. 222.--b.u.t.t Hinge.]

[Ill.u.s.tration: Fig. 223.--Gauging.]

[Ill.u.s.tration: Fig. 224.--Marking for Recess.]

[Ill.u.s.tration: Fig. 225.--Sawing for the Recess.]

ALIGNMENT.--Another fault that is fairly common is having the axes of the hinges out of alignment. Especially is this the case when three hinges are used to hang a wardrobe or other large door. It is absolutely necessary in all cases that the exact centres of the pivot-pins of the hinges should be in a straight line.

Particular attention to alignment is necessary when the body and the door frame are shaped on the face side. A familiar example that every reader may inspect for himself is the curved side of a railway carriage body and railway carriage door, where he will notice that a specially wide hinge has to be used at the bottom of the door to give the necessary alignment.

Hinges fixed on work with their centres out of truth are often overlooked by the inexperienced worker, and this is a frequent cause of creaking.

GAUGING.--Fig. 222 is a sketch of a bra.s.s b.u.t.t hinge, open. Fig. 223 ill.u.s.trates a similar hinge closed, and shows the gauge set so that the point of the marker is exactly to the centre of the pivot-pin. This distance we will call C. Now turn to Fig. 224. The distance C has been gauged from the face side of the frame. The gauge is then set to the thickness of the hinge at its thickest portion, and to prevent "hinge-bind" see that the gauge is set on the _fine_ side. Remember that the tapered point of the steel spur or marking awl will part the fibres of the timber a little more than the fine point, and give you a wider gauge line than was antic.i.p.ated when you set the gauge. The inexperienced worker nearly always overlooks this. The result is a hinge-bound door, the cause of which is not discovered by the worker because he is so sure that he has set the gauge correctly. The distance B, Fig. 226, shows the line gauged for the thickness of the hinge.

POSITION OF HINGES.--Another difficulty to the beginner is the position for his hinges, and it may here be stated that the general rule is to carry a line across the face of the work from the inside of the cross rail and place the hinge at E, as Fig. 224.

[Ill.u.s.tration: Fig. 226.--Tool Operation when Paring Out the Hinge Recess in the Door.]

SAWING FOR THE RECESS.--After marking out for the hinge, as shown at Fig.

224, take a fine-toothed saw (a dovetail saw is considered the best) and saw down as shown at Fig. 225, care being taken not to cut beyond the gauge lines. In this sketch three intermediate saw kerfs are shown, but if the hinge is of great length, say 5 or 6 ins., the removal of the waste wood will be greatly facilitated by the addition of more intermediate saw kerfs. These cuts sever the cross fibres and allow the timber to be easily pared away in short lengths.

In Fig. 226 we see the tool operation when paring out the hinge recess.

At the left of the drawing the recess is shown marked. Take a 3/4 in.

chisel and, using it as a knife (see A), deepen the gauge lines. Then stab the chisel downwards, as at B, to deepen the end lines. Next, take the chisel and pare away the back of the recess as at C. The work may then be completed by paring neatly till the bottom of the recess is flat.

[Ill.u.s.tration: Fig. 227., Fig. 228. The Hingeing of a Box Lid.]

STOPPED HINGED JOINTS FOR BOX WORK.--Fig. 227 is a section through a small box similar to a lady's work-box (the back of the box in the ill.u.s.tration is enlarged in thickness to clearly show the position of the hinge). In this case the knuckle of the hinge is let into the woodwork until it is flush with the back of the box, and the gauge would have to be set to the total width of the hinge. The back edges of the lid and the back edge of the lower portion of the box are planed away at an angle of 45 degrees as indicated by the dotted lines.

Fig. 228 shows the same box with the lid open, and it will be observed that the chamfered edges come together and form a stop which prevents the lid falling backwards and breaking the box. This method of letting-in the knuckle flush is a useful one for box work because the ordinary stock bra.s.s b.u.t.t hinge can be used. Attention may, however, be called to the "stopped b.u.t.t-hinge," which is specially made to answer the above purpose; in its action a similar mechanical principle as the one applied to the box is used.

[Ill.u.s.tration: Fig. 229.--Strap Hinge.]

[Ill.u.s.tration: Fig. 230.--Reversible or Double-folding Screen Hinge.]

[Ill.u.s.tration: Fig. 231.--Pivot Hinge for Screens.]

[Ill.u.s.tration: Fig. 232.--Non-reversible Screen Hinge.]

TYPES OF HINGES.--Fig. 229 is an elongated variety of the b.u.t.t hinge, known in the trade as "strap hinge," "desk hinge," or "bagatelle hinge."

As its name indicates, it is used on folding bagatelle tables, small writing desks, and other types of work that have but a narrow margin on which to fix the hinges. The long, narrow plates are sunk flush into the wood, the knuckle or rounded portion projecting.

[Ill.u.s.tration: Fig. 233.--Back Flap Hinge.]

[Ill.u.s.tration: Fig. 234.--Card Table Hinge.]

[Ill.u.s.tration: Fig. 235.--Pivot Hinge.]

[Ill.u.s.tration: Fig. 236.--Rising b.u.t.t Hinge.]

Fig. 230 is an ill.u.s.tration of the reversible or double-folding screen hinge. Half the thickness of this hinge is let into each wing of the draught screen, allowing the screen to be folded either way. The hinge is costly, but effective in use.

Fig. 231 is a type of pivot hinge which is used to fix at the top and bottom of a screen.

Fig. 232 is the non-reversible screen hinge and, as its name implies, will only fold in one direction.

Fig. 233 is a back flap hinge with a specially wide wing, used for the fall-down leaf of small tables and similar articles.

Fig. 234 is a card table hinge. This is let into the edges of the table, so that all is flush or level both above and below the surface.

CENTRE OR PIVOT HINGES.--Fig. 235 is a centre or pivot hinge, used on the top and bottom of wardrobe doors, more particularly the interior door of a three-winged wardrobe where the method of fixing is confined to the cornice and plinth. The f.l.a.n.g.e carrying the pins or pivot is let into the top and bottom of the door, the remaining f.l.a.n.g.e being let into the cornice and plinth respectively.

RISING b.u.t.t HINGES.--Fig. 236 is the rising b.u.t.t hinge, used on dining and drawing-room doors, so that when the door is opened the door rises sufficiently to clear the thickness of the carpet. This hinge has also an advantage over the ordinary b.u.t.t hinge in that it is self-closing, _i.e._, the weight of the door _plus_ the bevel on the hinge joint causes the door to close. Band and hook hinges and other ordinary varieties are too well known to require ill.u.s.trating.

ACUTE ANGLE HINGEING.--Fig. 237 is a sectional plan of a corner cupboard showing a good method of hingeing the door. The inset _a_ shows an enlarged view of the corner carrying the hinge, also the adaptor piece _c_, which is fitted to the inside edge of the cupboard so that the hinged edges are at 90 degrees to the face. This is a far better and stronger method than that shown at _b_, which is often attempted with disastrous results. The incorrect method _b_ allows insufficient wood for fixing purposes, and in nearly all cases the thin edge of the door breaks away during the making and fitting, or soon after completion. The adaptor piece may have a face mould worked upon it to give a pilaster-like appearance if fancy so dictates.

[Ill.u.s.tration: Fig. 237.--Hingeing Door of Corner Cupboard.]

[Ill.u.s.tration: Fig. 238.--Inside Hingeing: Method of Letting b.u.t.t Hinge into Door Frame and Carcase.]

INSIDE HINGEING.--When a door is being hung _inside_ the carcase (that is, not hinged _over_ the ends) it is permissible, in the case of light work, to let the whole thickness of the hinge into the door; and when s.c.r.e.w.i.n.g the door to the carcase it is usual to fix the knuckle of the hinge flush with the face of the carcase, thus allowing the door frame to stand back, making a break of about 1/8 in. with the face. The marking gauge should be set to the full width of the hinge; the mark, gauged on the inside of the carcase end, thus forms a line to guide the worker whilst fixing the door. To successfully fix a door it generally requires two persons, one to hold the door in position, whilst the other bores the holes and fixes the screws.

[Ill.u.s.tration: Fig. 239.--Showing Top and Bottom of Carcase Cut Back to allow Door to Close.]

[Ill.u.s.tration: Fig. 240.--Outside Hingeing.]

[Ill.u.s.tration: Fig. 241.--Section.]

Fig. 238 shows the correct method of fitting b.u.t.t hinges on high-cla.s.s work. One wing of the hinge is let into the door, and the other wing is let into the carcase or door jamb, thus distributing a proportion of the weight to the carcase end instead of allowing the whole of the weight to be carried by the screws as would be the case in _a_, Fig. 237. The method of sinking each portion of the hinge into the door and carcase respectively is costly; hence it is not the general practice in cheap work. In Fig. 239 the top and bottom of carcase (T and B) are shown set back to allow the door to close.

OUTSIDE HINGEING.--Fig. 240 ill.u.s.trates the portion of a door frame and carcase end when the door is hung on the face of the carcase. The correct method of letting in the hinge is shown in the enlarged section (Fig.

241), but, as previously mentioned, the hinge may have its entire thickness let into the door frame where it is of a light character. The door frame projects slightly over the carcase end, and occasionally a bead mould is worked on the edge of the door so as to give a finish and partly hide the joint. The bead would, of course, be the same size as the diameter of the knuckle of the hinge; and the knuckle, therefore, will form a continuation of the bead and give a workmanshiplike finish.

FALL FRONTS.--Fig. 242 is a sectional view of a fall front writing bureau fitted with centre or pivot hinges and arranged so that the edges form a stop when the desk front is turned to a horizontal position. The position for the fitting of the bra.s.s plates carrying the pivot-pin is somewhat awkward; but, by first sinking the plates into the carcase ends, and then slotting the edges of the fall, it will be found that the fall front may be put in from its horizontal position, and that sufficient room is left to enable the screwdriver to be manipulated without inconvenience.

[Ill.u.s.tration: Fig. 242.--Fall Front of Writing Bureau.]

[Ill.u.s.tration: Fig. 243.--Revolving Fly Rail for Table. See Pivoted Fly or Front Rail.]

[Ill.u.s.tration: Fig. 244.--Draught Screen Tape Hinge.]

FLY RAIL.--Fig. 243 is a sketch of a small table with the top removed. A revolving fly rail is shown pivoted upon a piece of 1/4-in. wire. The object of this fly rail is to form a support to the small hinged drop-leaf of the table. This method is suitable for small occasional tables and similar articles.

DRAUGHT SCREENS.--Fig. 244 ill.u.s.trates the end elevation and plan of a draught screen which is constructed of a light framework and covered with baize or American cloth. The reversible double-folding hinge (Fig. 230) would answer admirably for such a screen. Cases occur, however, where it is desired to hinge a screen to be used for an invalid's bedside, and it is then important that all draught should be excluded through the jointed edges. The double reversible hinge will not fulfil these conditions, and the following method is therefore adopted.

In the plan, Fig. 244, A and B, two laths of hardwood (beech, birch or mahogany answer splendidly) are shown. They are made the same length and the same width as the edges of the screen, the corners being slightly rounded away.