For Practical Workers
How to Make an Efficient Boiler-Patch
THE usual method of patching a boiler cannot be relied upon for high efficiency. Suppose there is need of a patch at the check-valve hole of a locomotive-boiler. The radial cracks,
most often along the length of the plate, start out from the hole. If a disk of boilerplate is applied with a single row of rivets, as shown in Fig. i, there is danger of tearing the boiler-plate or the patch, between the rivets; also of shearing the rivets.
The more rivets are used, the weaker the patch, since every hole weakens the plate. This may be seen by examining Fig. 2. The first piece of cardboard is solid all the way across ; the second has a hole in it, making the resistance to tearing just that much less. The only way to prevent shearing the rivets is to add more rivets opposite the defect, but this increases the number of holes and actually weakens the plate.
This difficulty can be avoided by the use of a patch like the one shown in Fig. 3. Two rows of rivets are used. The additional number of holes does not weaken the patch, however, because the force tending to pull the plate apart does not act at right angles to the line of rivets. The component of this force is to be reckoned with and the greater the angle of the rivets the less this force will be. By multiplying the number of rivets it is possible to mass more metal opposite the defect than there would be in the original plate, and the efficiency in shearing will be even greater than one hundred per cent. The observance of this simple expedient, which simply takes into consideration a principle of physics, will result in far less danger from weak spots in a boiler.
An Easily Made Mercurial Barometer
THE accompanying diagram, Fig. i, shows a useful barometer of simple construction. The baseboard A may be of mahogany, 38 ins. long, 2'/t ins. wide in the central part and 4 ins. at the ends. A straight glass tube B is'needed, 36 ins. long and about % in. in bore. After filling by the simple method about to be described, it may be fastened to the center of the board by means of
neat brass saddles. The cistern C, to be described in connection with the method of filling, is provided with a wider saddle at the lower end of the board. This may be hidden, for the sake of appearance, by means of the polished mahogany disk M. The appearance will be improved by turning the disk, or providing a small beveled mirror in the center. The upper end of the tube may also be concealed by means of an ornamental disk of turned wood.
It is in filling the tube with mercury that most amateur barometer makers experience the principal difficulty, owing to the necessity for excluding air. The regulation method is fairly easy in experienced hands, but the following will be found much simpler. The tube
B, Fig. 2, is of soft glass with walls of medium thickness. It is therefore a simple matter to make a constriction at X, 3 ins. from one end, by softening the tube in the flame of an alcohol lamp and drawing the ends gently apart. To the open end above the constriction should be attached a short length of India rubber tube D, capable of being closed with a brass clip or pinchcock E. The other end of the tube’should be passed through an India rubber cork, fitting tightly into a wide glass tube
C, forming the cistern. A bent tube F, previously passed through the cork towards the side, serves for connection with a cycle-pump and valve, with thickwalled rubber tube.
Let the tube be supported vertically, the cistern being rather more than half filled with mercury—before inserting the cork, of course—and force a little air in with the pump so as to drive mercury into the tube to about two-thirds of its length. Without removing the cyclevalve attached to F, that is, without letting any air escape, lower the tube gradually in a slanting direction. The mercury will rise still higher until it passes the constriction and fills the India rubber tube. Then close the pinchcock, remove the valve from F, and replace in the vertical position. The mercury will come to rest somewhere near the end of the tube, as shown in Fig. 2. The space above it is a vacuum since the air has been driven out and prevented from re-entering. The upper end of the tube above the constriction is no longer required and may be removed by directing the alcohol lamp flame against the narrowest portion with a mouth blowpipe, (or even an odd piece of thin tube), the same operation serving to close the top of the barometer tube with a neat and perfectly airtight seal.
A scale of inches and tenths must be made on glazed cardboard or imitation ivory and attached to the top of the board, a similar scale being fixed on the other side of the tube to show the words “rain,” “fair,” etc., if required. It is presumed that reference can be made to a standard barometer for the purpose of determining the points of the scale. Two comparisons should be made on different occasions, once when the standard instrument is very low, and once when it gives a high reading. Say the two readings are 27 and 31 ins. respectively. Then the distance between the two corresponding positions On the homemade barometer may be provisionally divided into 40 equal portions and called tenths of an inch, the figures being marked to correspond. But an effort should be made to check as many of these intermediate positions as possible by comparison with the standard instrument.—H. J. GRAY.
Killing Vermin with Gas
HYDROCYANIC-ACID gas is one of the most efficacious agents in ridding households of such pests as bedbugs, fleas, cockroaches, ants, clothes-moths, etc. Rats and mice, when exposed to its fumes, run out of their holes into the open and die there. There is thus no subsequent annoyance from dead rodents in the walls and under flooring.
Even when only one room of a house is to be fumigated the entire house must be vacated and so closed and marked with signs that everyone is kept out. The windows in such a house must be equipped with ropes so that they can be opened from the outside when the fumigation is done. If the house is close to another, especially if its windows are below those in an adjoining house, care must be taken to protect neighbors. This is especially necessary in the case of a house in a row, particularly if the partitions separating houses are not tight, or if its attic or roof air-space communicates with those in the neighboring houses. For these reasons, in the case of summer cottages at beaches, it is safest and easiest to fumigate before the family or neighbors have moved in, when there is plenty of time to air the house completely after it has been treated.
While hydrocyanic-acid gas is probably the most efficient means of ridding a house of vermin, it is also one of the most deadly poisons. Therefore, the greatest care should be exercised in its use.
A Wallpaper Remover
THE difficulty and inconvenience incident to the removing of old wallpaper and the preparation of the wall for redecoration are reduced to a minimum by the use of a new tool that gets at the root of the trouble. It works under the paper, or, rather between the paper and the wall, softens up the paste or glue and freely strips the paper from the wall.
It is particularly adaptable where there are several layers of paper to be removed, or for stripping off extra heavy or varnished paper. The usual way of flooding the walls with water or filling the room with steam are not necessary. The simple mechanical device illustrated generates steam on the ' spot with a gasoline burner and the steam is controlled by a valve in the hand-piece where it is driven behind the paper in a thin sheet.
A Non-Spillable Funnel
FUNNEL which will cease flowing automatically when the vessel into which the liquid is being poured reaches a certain, height, can be devised by attaching a metal float to the tapering funnel-tip. The float is a small metal cylinder closed at both ends. Small brass tubes should be soldered on opposite sides of the float, as indicated in the drawing. Nails which will fit loosely in the tubes should be soldered at their points to the tip of the funnel, with the float in place.
When liquid is poured into the funnel, it will flow past the float until the vessel is nearly filled, whereupon the float will rise and check the funnel’s discharge. The funnel can then be withdrawn quickly, so that little or no liquid is lost.
It is also advisable to use a funnel with a widely diverging rim to take care of the overflow. When the float is suddenly pushed up against the spout the liquid begins to rise in the funnel, making this necessary.
A Dark-Room Lamp
A VERY handy dark-room lamp can be made from a cigar box. After tearing off the cover, cut a hole in one end just large enough to allow it to be slipped over an electric light bulb and porcelain receptacle. Paste ruby paper over the opening. A fifteen-watt lamp will not' be too bright.
When the room is to be darkened, this is put over the light. When not it is simply left off. With this, one can get along with one light in the developing-room.
A Handy One-Drop Oiler
A VERY _ use1\. ful oiler made from materials to be found in nearly every box of odds and ends is here shown.
The oil container is a dust cap from an old automobile tube. A F^-in. plug is cut from an old valve-stem and a washer fitting this plug is soldered to it at the center. A six-penny nail which will fit the hole in the plug is soldered in place and flattened at one end. A leather washer should be made for the plug and the oiler is ready for use. This oiler will be found handy around the house as well as in the garage.—F. W. NUNENMACHER.
Rubbing in the Lathe
THE writer had a number of pieces of cast-iron to be filled with machine filler after which they were to be rubbed smooth and flat.
Rubbing by hand was slow and
the surfaces hard to flatten.
The cut shows the fixture used for rubbing; it worked very successfully. The shank A Fig. i, is held in the chuck of the lathe and the face B, turned flat. To the face B, a piece of coarse emery cloth is glued and the “rubber” revolved at a fairly high speed. The work is held by hand against the revolving “rubber” until the desired results have been obtained, after which they are finished by hand, rubbing with fine emery cloth.
After the emery cloth has been glued to the “rubber,” it should be placed face downward on some flat surface and weighted down. The kind of work for which this fixture was used is shown in
The bed of the lathe should be covered to keep the emery away from the bearingsurfaces.—C. ANDERSON.
An All-Steel Screwdriver
THE screwdriver to be described is constructed entirely of steel and while feeling heavy at first will be found to be very well balanced and able to stand hard usage. If the blade is broken it can be easily repaired or replaced or different sized blades may be used.
The whole tool, including the fluting of the handle, was made on a small back-geared lathe with a hand-fed carriage.
A 5" length of 1^2" cold-rolled steel shaft was cut off and a 3/8" hole 3" deep bored in the center of it to take the blade. The handle was then roughed out nearly to the finished dimensions and a light finishing cut taken all over it at high speed.
The handle was fluted as follows: The circumference of the large end was
divided and punch-marked into twelve equal parts. Then a hole was drilled and tapped for a %" set-screw in the small part of the handle, as shown in the drawing, and a length of 3/8" rod set in and countersunk for the set-screw. The outside end of this rod was held in the lathe-chuck, the large end of the handle being held in the back-center. A steel lathe-tool with a small rounded end, was placed in the tool-post turned over on its side; the lathe-chuck wras kept from turning by locking the backgears, and then each groove was cut by moving the carriage along by hand and taking a succession of light cuts until the groove was of the required depth.
The blade was made of a piece of z/% tool steel with the tip end hardened and was held in the handle by means of the W set-screw, countersunk about }/% . A set of blades could be made of different lengths or with tips of different widths.
A Buck-Saw Attachment
THE ordinary buck-saw frame has a tendency to cramp the upper hand when sawing. To eliminate this, bore a ^ in. hole through the top part of the frame just
below the tightening wire. Cut off a piece of an old broom handle 4 ins. long and drive it through this hole half projecting on each side. By gripping this pin with two fingers on one side and two other fingers on the other side, with the saw frame between, the wrist will not be twisted.—W. J. ALBIN.
How to Etch Glass
WARM a piece of glass carefully ; if heated too rapidly the glass will crack. Rub paraffin or beeswax over the warm surface of the glass.
With a blunt instrument print the desired wording. To some fluorspar (calcium fluoride) placed in a metal dish, add enough concentrated sulphuric acid to moisten the powder. Place the glass, with the marked side down, over the metal dish containing the above chemicals and leave it over night. In the morning, scrape the paraffin off and the desired words will be etched on the glass.
Bonding Joists to Brick Walls
THE illustration shows how it is best to bond joists to hollow tile walls in the building of residences. A piece of J^-in. by 2-in. strap-iron is spiked to the joists as shown. The outward end has a hole bored through it and holds a >2-in. steel rod that is io ins. long. This rod fits into a groove in the top side of the tile in the mortar joint.
This scheme makes a solid connection between the floor joists and the hollow tile walls.—W. E. FRUDDEN.
Emergency Control of Motor
AMETHOD is herewith illustrated for stopping a motor at will from any part of the shop. When the pushbutton is pressed the circuit is open and the lever will fly back, stopping the motor. A number of these buttons connected in series may be used, one by each machine. Should anything happen to the operator the button could be pressed and the motor brought to a stop at once. In the construction of the push-button a spring keeps the disk in CONTACT.-FRANK HARAZIM.
A Drainage Kink
IN the installation of an 8-in. steam line, using present headers and steam openings in a steel and brick building used for gas-making purposes, it was found that to place the line with least expense and to drain back to the boilers, a 12-in. I-beam was in direct line.
To go over or under the I-beam meant a trapped line and use of a steam trap. To avoid the use of a steam trap and take care of condensation the connection was made as shown below.
An 8-in. line was installed using 45-degree bends over the I-Beam and a two-inch drain line underneath the I-Beam. The two-inch line takes care of condensation and gives drainage back to the 8-in. line which in turn drains to boilers.—W. W. FLANDERS.
A Screwdriver Handle
A SPLIT screwdriver handle may be neatly'repaired by means of wire and solder. Place the end of the split handle in the lathe chuck. The jaws will force the split parts' into nearly their original position. Make a slot around the handle wide enough to take four or five turns of wire and deep enough so the wire will be below the surface. If a lathe is not available, the handle may be held in a vise and the slot cut with a knife.
With a hand drill, make a hole near the slot in which to start the wire. The hole should be as nearly the size of the wire as possible. Wind the wire on tightly. Holding the end with pliers, cover the wire with solder, forming a solid metal band. Smooth the solder with a file, and the screwdriver is as good as NEW.-B. H. LIBBY.