Where city gas is available as fuel, the brazing stand at D is a practical article of repairshop furniture. This consists of a large cast iron table carrying an air receiver between the legs and fixtures to support the brazing torches at any desired position above the table top. The top of the table is protected by fire brick, which members are also used to form a furnace to concentrate the heat upon the

Fig. 40.—Outlining Construction of Supporting Member for Chain Fall Attachment and Appliance for Cleaning Machine Parts with a Gasoline Spray.

pieces to be brazed. Complete instructions for use of this and other forms of brazing appliances to be described will be found in chapter dealing with miscellaneous processes.

The utility of the chain falls has been previously considered, and it is somewhat a problem to provide a substantial method of supporting these in shops where the overhead trolley is not provided. The illustration at the left of Fig. 40 shows a very simple and strong supporting fixture for chain falls or other hoists and may be easily made by any repair shop mechanic in spare time. As

all parts of the device are clearly shown and dimensions given, further description is unnecessary.

One of the most disagreeable jobs incidental to repairing is cleaning the accumulation of oil, road dust or grease from parts to be worked on. The common method by means of a brush and gasoline is wasteful and time-consuming, and it is not possible to penetrate all corners thoroughly, as many of these are inaccessible. Gasoline or kerosene under pressure will remove dirt without using large quantities of liquid. A typical cleaning outfit is shown at the right of Fig. 40. This consists of a large receiver fitted with a pressure gauge and with a shut-off valve to which a hose connection is made. The tank is filled about half full of the cleansing liquid. The hand pump provided is used to force air pressure into the container in order to produce a spray of liquid having force enough to dislodge the particles of dirt. These are inexpensive and will save their cost in a short time by the saving in cleaning liquid.

In some large cities, notably New York, Chicago and Boston, there has been considerable agitation on the part of the municipal and insurance authorities toward the enactment of legislation making it compulsory for the automobile repair shop or garage proprietor to install separators attached to the floor drains in order to prevent volatile inflammable oils, such as gasoline, kerosene and lubricants from flowing into the sewer. A device which has been proposed by the New York authorities is shown at Fig. 41. It is built of boiler plate and standard pipe fittings and the proportions can be easily ascertained by inspection of the illustration. The floor drain is connected to the main drum upper portion and all water from the floor must flow into that chamber before it can pass into the sewer. As gasoline and lubricating oil are lighter than water, they will float on the top of that liquid and will drain off through the vertical stand pipe extending from the partition forming the top of the lower compartment to a point just above the water line. The lower compartment is provided with a gauge to show the height of liquid, a drain cock by which the lower compartment may be emptied and a large cleanout plug for the removal of sludge and residue that will not drain out through

the cock. A vent pipe extends from the lower compartment to the air in order to prevent the accumulation of any pressure due to gas generation from vaporization of the volatile liquids. The

Fig. 41.—Separator Intended to Keep Volatile Inflammable Liquids from Entering City Sewers.

upper portion of the container and the pipe connections are also provided with cleanout plugs.

Another form of separator is shown at Fig. 42. This is marketed to meet the requirements of the fire and building departments of New York City and is known as the Paragon Separator. It is said that the best position for this device is near the side walk and

under the floor with a hand pump projecting through the floor. The waste water containing gasoline and oil enters the branch floor drain and flows into a sand box where all solid matter is extracted. From this point the liquid flows through a screen into a U-shaped container and then out through a discharge pipe into the street sewer. Inside the main portion of the U-shaped container is the cylindrical oil chamber in which the volatile liquids are collected.

Fig. 42. Another Form of Separator for Garage or Repair Shop Use.

As before stated, these are lighter than water and will float on the surface and thus enter the oil chamber through a suitable opening at the back of the cylinder. An indicator with a ball float shows the level of liquid in the oil chamber and when a sufficient quantity is indicated it may be drawn out by a hand pump. Two air vents are provided, one running to the roof for taking out the impure air, while another one runs to the sidewalk to let in fresh air which is heavier than that saturated with hydrocarbon vapor, thus driving it

out. The sand box is placed in a convenient position so to afford ready access when new filtering material is needed. Relief pipes are provided in both the U-shaped container and in the oil chamber to prevent the accumulation of any pressure in either of these portions of the separator.

Air Compressor Types.-All up-to-date repair shops, especially

Fig. 43.-Portable Electrically Operated Air Compressor Outfit.

if they are an adjunct to a garage, or if they cater to tire repair work, have some power-driven source of compressed air. A blast of air has many uses besides that of filling pneumatic tires, as it can be used for blowing out loose carbon particles from the combustion chamber or light chips and steel fragments from gear boxes or rear axle housings. The air blast may also be used for cooling heated steel gradually when annealing it and can also be employed for