(49) Another important item which is generally overlooked in the average welding shop is the question of ventilation. Although the welding flame itself contains no objectionable gases, those from fresh charcoal preheating fires, those given off when some of the alloys of the filler-rods are melted when brass, copper, and other metals are being worked on, and from gas engine exhausts are not desirable. At times they will give the operators violent headaches unless means are taken to carry them off. The ventilation should be such that it will not directly affect the work. Drafts are to be avoided as much as possible, for many times they will warp pieces being preheated if allowed to come in direct contact with them. It is a good thing to remember that indirect ventilation and plenty of it is a prime requisite in a good welding shop.
CHAPTER IV
APPARATUS REPAIRS
(50) Occasionally in setting up a welding apparatus, a leak may be noticed along the lines, some time after the plant is in operation. Leaks on either the oxygen or acetylene lines are to be considered dangerous as well as costly and therefore to be avoided at all times. When the cylinder valves are closed on the drums containing the gases, and the hands on the low-pressure gauges of each regulator are seen to drop or reduce their pressure when the torch valves are shut off and allowed to remain so, this is an indication that there is a leak between the regulator and the torch. It is not desirable to use a match or a flame of any kind in testing for leaks. There are various methods employed by the cautious welder, but about the best of these is a soapy solution of water, which is kept in a can at all times and is applied with a paint brush. If this solution is applied to any leaky part, bubbles will form immediately and the leak will be located.
(51) At times, when working in isolated places, where repairs cannot be had, and no means have previously presented themselves for testing out the cylinders or the apparatus as a whole, it may be found that the threads or ground seat on the cylinder valve of the regulator which is connected will be in such a condition that a leak is in evidence. Or it may be that the threads will not permit the seat being drawn up sufficiently to make it airtight. In cases of this kind, the welder must find some means of proceeding with his work, and while it will be impossible for him to use white lead or any oily substance with safety, he may stop the leak with litharge or lead oxide mixed with a small quantity of glycerine. A string soaked in this solution may be wound around the main connection and the swivel nut screwed up to the seat as far as it will go. If allowed to harden for a short time, the litharge will set and a very satisfactory temporary repair will be effected.
Fig. 32.—Method of Attaching Hose to Connection so it cannot Pull or Blow off.
(52) The method shown in [Fig. 32] of attaching connections to hoses so that they will not blow off when pressure is applied is a very simple and effective means of overcoming this difficulty. Undoubtedly it will assist some operators in solving the trouble that has been occasioned by the ordinary hose clamps, especially when doing cutting or heavy welding work where the gas pressure is considerably higher than usual. The wire used should be large enough to prevent cutting the fabric in the hose.
(53) An injured hose which may leak should never be used after the leak is noticed unless some means are taken to repair it. The use of tape in trying to repair hose on an oxy-acetylene welding outfit should never be permitted. The most efficient way of overcoming an injury of this kind is to cut the hose at this part and insert a piece of pipe. The ends of the hose are then wired to this pipe and a union is thereby effected which will generally outlast the life of the hose. Special connections for this purpose are put out by most welding companies, so that a supply may be on hand if hose trouble is expected.
(54) When transporting welding apparatus, occasionally the “cross-bar” on the regulator is lost and many times the operators do not know what is to be done. The purpose of the “cross-bar,” as we have already seen, is only to apply pressure on the diaphragm springs, so that if a set screw of the same diameter and same thread as those of the “cross-bar” can be found and screwed into its place with a wrench, a section of filler-rod can be welded across the top of it and the use of the regulator will not be impaired. If a special thread is used by any particular company, a piece of brass or iron can be turned down in a lathe to fit.
