Welding – the most reliable way to connect among themselves two or several metal objects. Welding connections with success are used both in the industry, and in living conditions. Many of fans independently to design or repair things regularly uses services of professional welders. However, in the aspiration to save time, money for payment of professionals, and some just from interest try to learn to cook.
- - welding machine with electrodes;
- - safety mask and equipment;
- - hammer and brush on metal.
1. The equipment for carrying out welding can be leased, bought or assembled independently. The choice of transformers, rectifiers and inverters, as well as schemes of their independent assembly is rather broad. All of them will transform household voltage of 220 V to welding current. When choosing the transformer it is not recommended to buy too cheap devices – they do not provide stable electric arc and stability of tension. Besides they are quite heavy also shumna in work.
2. Rectifiers, unlike transformers, provide good, stable arch, but also are significantly more expensive. But inverters are considered as the most effective devices. They give good arch, do not give drawdowns of tension, have the small weight and good performance.
3. Irrespective of type of the chosen welding device, it will have 2 cables. One of them – negative, to it usually fastens electrode. Another – positive (weight), it is connected to part. However, when welding some materials (stainless steel, for example) the polarity is changed. Minus is given on preparation, plus – on electrode.
4. As electrodes the universal firm rods covered with the melting structure, having diameter of 3-3.2 mm are suitable for beginners more. For thin metal it is necessary to choose thinner electrodes, for thick metal – thicker. But thick midstreams require also more powerful equipment. Trace also that electrodes were not really old. The stale and dampened electrodes it is even difficult for professional to cook, without speaking about the beginner. Except ordinary metallic electrodes also nonmetallic are issued: graphite and coal. They are applied to performance of special welding so in the course of training will not be useful.
5. It is necessary to take care also of equipment. First of all the welding mask or guard, on hands – tarpaulin or suede mittens, on body – dressing gown or overalls from tarpaulin or the rubberized fabric is necessary. Also take care of fire safety in case of hit of spark on flammable objects. Fire extinguisher, for example, or just container with water.
6. Development of welding skills – the process demanding patience. Therefore for the first classes it is better to stock up with packing of electrodes and any unnecessary sheets of metal.
7. Before welding prepare the welded parts. Smooth out working surfaces of parts from dirt and rust metal brush. Insert electrode in the special holder of the welding machine. Attach the grounding cable (masses) to the welded part in the place which is in advance smoothed out from paint, rust and dirt. For convenience the welded parts can be clamped in vice. Straighten edges of preparations and smooth out to metal gloss at distance 1 cm from edge. This cleaning is necessary more quicker to learn to cook.
8. For receiving welding seam it is necessary to create electric arc. For this purpose strike electrode on metal or slightly knock with it. Usually during the work with new electrode the arch is lit easily. During the work with the rod which was in the use it is recommended to beat off several mm of covering on the end of electrode. Even if after several attempts the arch has not appeared, check reliability of accession of positive cable (weight).
9. When the electric arc arises, bring the end of electrode to position of joint of metal parts. The gap between the connected surface and arch has to make 3-5 mm. During all welding try to keep gap constant to receive qualitative and equal weld. Also try not to interrupt arch until the connected parts are not welded. Move electrode slowly, so "to experience" welding process, carefully to boil thoroughly preparations and to learn to hold electrode.
10. When welding try to hold electrode at an angle of 60-70 degrees. It is possible to change this corner only when boiling hard-to-reach spots where it is impossible to keep rod under this corner. Do not forget to watch also current intensity. All welding machines have the handle of adjustment of current intensity. If to cook too weak current, the arch will spontaneously die away, and too strong – metals will be melted, but not to cook. Approximately it is possible to calculate current intensity, having increased 32-38 Amperes by each millimeter of thickness of electrode. Three-millimetric electrode it is necessary to cook at current 80 A. Current in 100 Amperes and cut metals above.
11. Quite often in the course of welding the electrode sticks to metal. To tear off it it is not necessary to put a lot of effort. Just shake electrode here and there, slightly disconnecting it from preparation. After that create electric arc anew. To eliminate such sticking in the future, slightly increase force of welding current.
12. Electrodes, melting, gradually burn out. When the electrode comes to an end welding stops, the fulfilled electrode is replaced new, the slag formed on welding seam cleans up the hammer or brush. The welding arch joins again, the Last 10-12 mm of already ready seam are boiled once again. The rest of old electrode has high temperature therefore at its utilization do not neglect measures of fire safety.
13. The simplest welding seam – straight line. At its performance the electrode moves directly across. The tip of electrode makes oscillating motions with an amplitude of 2-3 mm, selecting the melted metal in the roller. It is possible to make also more great oscillating motions if it is necessary to execute thicker seam.
14. If desired it is possible to master also more difficult seams: in the form of fir-tree, loop, zigzag and others. To weld not only simple sheets of metal, but also to cook end-to-end, with an overlap, to make T-joints. After completion of welding the seams and cooling of seam smooth out from surface slags the hammer or brush on metal. Slag is formed almost always as a result of combustion of powdery substance (gumboil) which has covered electrode.