your life's work if a lump of calcium carbide is dropped into water bubbles of gas will rise if this gas is ignited with a match it will burn the gases acetylene and when mixed with oxygen in the proper proportion it produces the intensely hot blue oxyacetylene flame used in welding the equipment necessary for oxy acetylene welding consists of a cylinder of oxygen and oxygen regulator a cylinder mounted on a hand truck such an outfit is readily portable and can be taken to the work no matter where it may be located for large scale welding operations the equipment is somewhat more elaborate oxygen and the settling may be piped throughout the shop for a plant from a central point in all welding suitable clothing must be worn to protect the welder or oxy acetylene welding goggles must be used with lenses of special colored optical glass which protect the eyes from the bright flame and the metal the welding torch mixes the oxygen and the settlin together in correct proportions separate valves regulate the volume of oxygen then the settling in lighting the torch the acetylene valve is first open slightly the friction lighter which strikes us spark is used the oxygen valve is open and the mixture of oxygen and the settle in adjusted because the temperature of the flame can be varied deceit the type of work the oxy acetylene welding process is a very valuable one the pieces of metal to be welded together must be prepared properly so they are free of any foreign matter they are held in position with do allowance for shrinkage when the flame is passed over the edges the metal is quickly heated to a plastic state the welding operator uses a welding rod metal similar to that being welded the metal from the rod is melted into the joint thus fusing the parts into one the easiest welding position is where the work can be laid out flat however when overhead they are vertical wells are made the temperature of the metal must be controlled very carefully or if it is too high the weld may sag or drop out the first class welding operator must be able to weld work in any position they must be able to weld all materials many various metals can be welded and welding is not only a trade in itself but a part of nearly all occupations in which metal is used including sheet metal work boiler making and steam fitting the welder often uses oxyacetylene flame for cutting iron and steel employing a cutting torch this is similar to the regular torture but it has an extra valve operated by the thumb or finger which controls a stream of  the metal is brought to a red heat at the point where the cut is to start the cutting oxygen valve is then opened the stream of pure oxygen combines chemical it with the hot metal and burns it away along whatever pattern the torch follows this process may be used to cut very thick metal and may also be used to cut metal underwater spot welding is one example of the type of electric welding known as resistance welding one of its important uses is that of joining sheet metal together the spot welder is a machine with two copper electrodes the sheet metal to be welded this place between the points of the electrodes and the current is turned on the resistance of the sheet metal to the electric current which passes between the electrodes causes to heat quickly to the fusion point and pressure on the electrode squeezes the metal together other types of resistance welding are similar in nature in arc welding the material to be welded is grounded to the generator either directly or through a metal table on which the work is placed the electric current is transmitted to the rod holder through a heavy cable touching the rod to the work completes the circuit and causes a spark or arc the intense heat of the arc melts both the metal and the welding rod causing them to fuse together in shielded arc welding the welding rod is coated with a special substance which forms a gas the gas shields the molten metal from the oxygen and nitrogen in the atmosphere thus preventing impure raise from forming a weld of high quality is the result when it is necessary to add metal to the joint only the metal being weld it is melted and the carbon rod or electrode which does not melt is used the mask worn by electric welding operators protects the face as well as the eyes the electric arc gives off ultraviolet rays so there must be no bear skin exposed and clothing must be worn which will protect the operator from byrne's proper ventilation is necessary for all indoor welding in production work the welding operator may work on only one kind of material held in a jig or form and with just one kind of welding equipment the operator may become highly proficient in specialized work and still not qualify as a skilled welder in other types of work different kind of steel or ally the job welder must therefore understand how to work with many materials in order to adjust his equipment correctly and select the right welding rod for each one if you plan to be a welder to be successful you must have good eyesight fine muscular coordination because much of the work is strenuous you should be strong in addition a good knowledge of welding principles is necessary along with practical blueprint reading and some mathematics electrical physics and some chemistry will be helpful many schools are for elementary shop courses in welding both during the day and at night there are many private welding schools many machine parts which used to be cast as one piece i now welded from steel plates this process provides greater strength with less weight and that lower cost in the automotive industry welding is implied in many ways it has made possible strong steel automobile bodies as well as the coaches and then gin cabs of streamlined trains lightweight and attractive  such welding is carefully inspected and if you choose welding as your life work it will be worth your while to work hard to qualify yourself as an inspector there are many welding jobs in shipyards large whole sections can be welded together in shops then hauled in the highest of the ways and welded into a complete hoe because no revenue hole john necessary welding is stronger than riveting weight which can be saved by using lighter plates and by a lemonade ing rivets increases the ships carrying capacity members are welded in constructing large buildings skyscrapers bridges another engineering projects in place of riveting them if you like outdoor work this offers an interesting job in the welding field as do many other types of job welding pipeline welding should also interest you welding crews travel across the country welding lengths of pipe together this work to is carefully inspected and you will have to pass special welding tests before you can do pipeline welding or weld any other high pressure equipment such as steam  new applications of welding are continually being employed in many industries and as a result the welding field will probably continue to grow all the welding operator who develops real skill