3.2 Gas Welding
This is the oldest welding connection of copper and places special demands on a welder´s experience. The following welding forms are proposed:
The seams are not stapled because of the high thermal expansion, but only held with clips. Suitable fluxes may be applied broadly to the top and bottom. Preheating to Rotwärme. It is welded with a neutral set welding flame according to the left welsing method (welding with a lagging burner). It must be worked only in one layer (No rewelding - danger of cracking). With thick sheets in short steps reheating and hammering at Rotwärme. Best results are achieved with silver alloyed welding wires that , dditionally, can be used in all situations.
| Silox S 1 | Norm designation S-CuAg | Melting Range | 1060 - 1080 °C |
| Silox F 1 | Norm designation FH 21 | Range of working temperature | 750 - 1100 °C |
The flux residues are not hygroscopic and can be removed mechanically or by quenching.
A quick cooling leads to the formation of fine grain and thus increase quality. The welding joint is of the same color and just as chemically resistant as the base material. The electrical conductance of the welding rod Silox S 1 is between 30 - 45 Sm / mm ².
