It is the best of all to cook thin sheet steel gas welding. In this case higher quality of weld is provided, than at electric welding. However if you already have welding inverter and you should deal with thin-sheet metal only from time to time, there is no reason to buy the equipment for gas welding. Having put certain diligence, it is possible to weld thin metal and electric welding.
- the device for electric welding, welding electrodes of Ø2-3 of mm, sheet steel 0.8-1.5 mm thick, copper strip.
1. Welding thin metal you vnakhlestnalozhit the welded sheets at each other. The size of overlapping of one leaf another depends on flatness of edges. It has to be such that throughout joint the overlapping not less than 5 mm was provided. Achieve dense adherence of edge of the top leaf to lower by means of clamps or the pressing-down cargoes. The gap between sheets has to be excluded as its availability will lead to burning of the top leaf.
2. Establish the necessary size of welding tokavelichin of current depends on thickness of weld metal and diameter of electrode. For steel 1 mm thick it has to make 30-50 A. Smaller values are accepted for mm Ø2 electrode, big – for mm Ø3 electrode.
3. Before starting welding of the part, be trained on metal piece, similar on thickness. Trial welding will allow to pick up precisely the size of welding current, dependent not only from the values established on the device but also from line voltage. Besides, the welding test "will adjust" your own reaction as it is necessary to cook, constantly extinguishing arch and lighting it again, and the slightest delay with otdergivaniye of electrode will lead to burning of hole in metal.
4. Take sheets to each other. The holding strap is carried out by short crossing points of seam (about 5-10 mm) with distance between them 50-100 mm throughout joint. Conduct welding with periodic interruption – extinguishing arch (electrode otdergivaniye) and quickly lighting it again that metal has not managed to cool down. Time of continuous burning of arch depends on thickness of plate and current intensity. For leaf 1 mm thick and more thinly it has to make 1-3 seconds.
5. Weld sheets you polnostyyuvarit joint faltering seam, from time to time moving electrode to new (cold) zone of joint. It will allow to avoid strong buckling of metal – especially in case length of joint is rather big (more than 200-250 mm). The less length of continuous seam, the is less buckling. Begin to cook with one edge of joint, then pass to other edge, then move to the center, etc.
6. Welding of thin metal vstykdobeytes minimum clearance between steel edges on all length of joint. Ideal case is the total absence of gap. For welding of thin metal end-to-end use auxiliary lining which keeps within under joint. It is quite difficult to cook thin (1 mm and more thinly) steel end-to-end unlined though at availability of the welding inverter and good (import) electrodes quite perhaps. The technology of the welding (selection of welding current, use of holding straps, intermittence and poshagovost of welding) remains just the same, as well as when welding with an overlap.
7. Welding from the steel not cleaning up podkladkoyesla design of part allows availability of not cleaning up lining, enclose strip of steel of the same thickness, as well as the main leaf 13-15 mm wide under joint. Provide dense adherence to it of weld metal. Such lining will allow to weld part even if in joint there will be gap several millimeters. The lining in this case is welded on part.
8. Welding from copper podkladkoyesla the availability of not removed lining is inadmissible, enclose under joint strip from copper (the more thickly, the better). Copper will take away heat and will prevent burning of sheets. After the end of welding remove lining.
9. Welding from the steel cleaning-up podkladkoyesla not removed lining is inadmissible, and there is no copper strip, weld part with steel lining and accurately remove it with the grinder.