Basics of Soldering Precious Metals

Before soldering there are three factors which must be considered. The designing must impart itself to soldering, parts to be soldered must suit closely and accurately and the right solder and flux must be used.

Solders are typically classified according to their thaw points - easy, medium and hard. This therefore mentions to the easiness of thaw the solder. Hence an easy class solder runs before a difficult class one. This tin be used where a sequence of articulations are to be made. Usually a solder must conform to the same hallmarking regulations as the metallic element being joined - for example, a 9ct solder must incorporate at least 37.5% gold. However, there are some grants such as as Platinum Solders and some achromatic gold alloys.

Gas and compressed air mixtures are generally the most satisfactory for torch soldering. Fine accommodation of fire size and temperature are possible. The fire should be kept constantly on the move over the whole joint area, or over as broad an country as tin be conveniently joined, in a single application of solder.

The joint countries must be free from soil and grease, and ideally cleaned with a data file or emery paper to guarantee the solder will wet the parent metal. Flux should be applied to the joint country and solder prior to heating. Fluxes advance wetting of the workpiece by the molten solder. This is done by removing any oxide movies present on both the parent metallic element and solder and forestall additional formation of oxides during heating. The flux must be completely unstable and active before solder settlement and should stay so until after the solder solidification.

If the size of the joint is big additional flux improvers may be made during the process. It must be noted that heating of the workpiece may be required to guarantee full keeping of the flux paste over the whole joint area. The torch should initially be held some distance from the workpiece so that the fire heat ups the work generally. If constituents of different size are being joined the torch should predominantly heat up the heavier item.

There are two full general techniques used to use solid solder. Preplacement is where little pieces of solder are placed at the joint seam prior to heating. Heat is then applied until the solder flowings into the joint. Eating is where the fluxed articulation is heated up to temperature and tip of the solder wire is fed into the joint and should run on contact.

Using both these techniques the joint should be heated more than strongly than the remainder. The clip and temperature required to finish a joint must be kept to a minimum.

Gold and Ag flux residues may normally be removed by soaking in hot water. Any additional residues that prevail may then be removed by brushing. In hard lawsuits the workpiece should be impressed in 5 - 10% sulphuric acid solution for 2 - 5 minutes, rinsed in hot H2O and brushed again. For big scale of measurement soldering a little furnace may be used to supply sufficient uniform heat energy to the workpiece. For mass production batch or conveyor type furnaces may be used. However, the measures of constituents to be soldered must be big adequate to warrant the relatively high working capital outgo and development of a method for each peculiar soldering operation.

All workpieces can be successfully finished by the criterion patterns and procedures currently available. It must be noted that powdery borax makes not always ran into the demands for all applications, where the extended scope of other solders now available may be used.