Professionals and amateurs try to use welding in jewelry and small art together with brazing, soldering, spraying and other traditional for these purposes processes. Now electric welding becomes more necessary for platinum goods producing because in many cases gas flame gives not enough temperature for stable seams formation, as well as during manufacturing products made of stainless steel, titanium and other refractory alloys. At the beginning of 90s India possessed the leading position in jewelry production, while, for example, the USSR and Israel engaged the 15-17-th places in the world.

Now we see many more achievements in this branch among the USA, Asia-Pacific (especially China and Japan) and some European countries.

Nevertheless even now jewelry goods inseparable connections-joints are mainly produced in mass production by brazing and soldering in furnaces or using gas flame heating. The latter method is also applied by private jewelers, and in many cases they use small torches, feeding them by acetylene-oxygen mixtures from standard cylinders or by hydrogen-oxygen mixtures which the water electrolysis devices supply. Torches, which use H2O2 mixtures, are very light and appealing for jewelers. However, gas flames generate very large zone of heating, bringing problems connected with big deformations, sometimes - rejects and ecological problems. At the same time its temperature is often not enough for platinum goods welding and brazing. Platinum demand for jewelry has grown by 7% since 1980, and currently, 37% of platinum is used in jewelry (www.gold-eagle.com/editorials_05/struthers020905.html), while only 15% of the world gold resources are now used for the jewelry purposes (RBC daily, August, 11, 2006).

For a long time many attempts were made in order to find alternative heating methods for jewelry goods parts connection during their manufacturing. To constitute for such methods were argon (TIG), microplasma, electron-beam and laser welding. In the former USSR microplasma welding was for the first time successfully applied for gold rings manufacturing in the 70s. The USA began to use this method much later (you may see the M.R.Johnson's article "Jewelry Gets Extra Sparkle through Welding", "Welding Journal",1993, vol.72, N.1, p.p.73-75). It is clear that electrical welding (in its pure mode) may be only used in minority cases (welding of massive rings, so-called tennis bracelets,etc.). Indeed the latter type of goods were welded in the USA at the Company Stuller Settings.They used microplasma equipment and consultations from the Company L-Tec Welding & Cutting Systems. Unfortunately both of these companies do not exist anymore. We do not know what happend. But it seems to us that the used by them microplasma welding parameters were very sensitive to assembling conditions.In order to have a good quality of welding everybody has to pay much attention to the process beginning and especially - to the moment of its stopping. Indeed, at that moment there may be occur a hole or a crater on the jewelry good's surface.That is why for the past few years, we've been developing the combined processes of welding-brazing. At present the USA uses a lot of laser welding machines in jewelry. Such, not quite warrantious, tendency has a place in almost all the industrially developed countries.

Below we give the comparison of several joining methods and used by them equipment that may be relevant for jewelry purposes. We have built this Table based on the analysis of various sources (may be not very modern). Of course, this information is rather approximate, but (together with tables from our applications and dental laboratories rubrics) it gives the preliminary estimation of compared methods and equipment with respect to rather miniature jewelry goods. Here, speaking about minimum heating zone and energy usage, we bear in mind the main - transferred arc. With regard to the non-transferred, so-called pilot, arc we can only estimate its energy usage as about 10%. However, due to large currents of this arc, the new cheap, safe and simple sets have many more additional technological possibilities.

Heating source Minimum heating (mm2) Energy usage Equipment mass (Kg) Equipment price (US $) Relative cost of 1 working hour (%)
as it was estimated by
welding specialists of the East Germany
C2H4 - O2 flame 1 0.25 - 0.75 < 20 < 500 -
H2 - O2 flame 1 0.4 - 0.65 12 - 56 400 - 900 -
TIG welding 1/3 0.5 - 0.75 < 60 600 - 7000 100
Microplasma,
< 5A
1/200 0.4 - 0.6 < 20 < 5000 -
Microplasma,
10 - 15A
1/40 0.4 - 0.66 < 30 < 7000 -
Microplasma,
15 - 30A
1/10 0.4 - 0.72 < 40 < 10000 240
Electron beam 1/1000 0.7 - 0.9 > 40 > 30000 1600
Laser 1/10000 0.02 - 0.2 > 70 > 20000 4000

Indeed, besides strict welding, which for jewelry goods has to be usually operated at currents up to 30 A, new sets can be used for brazing and combined processes. It permits to avoid damages of very delicate goods at the time that the main arc current passes through them. Our experiments with the prototype of the new set showed that it may be very useful for local brazing when a piece of the paste material has been quickly melted on the surface of a thin metal strip (width nearly 5 mm, thickness of 0,24 mm, gold 18K) and gave a layer with a height more than 0,3 mm without this strip's noticeable deformation. Such effect opens new perspectives for producing delicate and unique items, with original or complex relief, without such expensive methods as casting, stamping, or special drawing. It may also be useful for repair works.We had reached first good results when brazing-welding bracelets (lap joints).

It must be added here that maximum temperature which may be achieved in microplasma arc, usual argon arc and gas flame is about 18000, 6000 and 3000 degrees, respectively.

In our opinion, microplasma processes are not used enough in jewelry now because their equipment is only 1,5-2 times cheaper than that of laser units; this equipment has rather limited technological possibilities and it is not quite reliable. As we hope, the cheap, safe and simple sets would be able to compensate this omission, in many cases being a good substitution of laser, resistance and gas flame equipment. Of course, in order to be in a real competition with the last equipment, our new sets have to be completed by light and manoeuvre torches (please, see our torches and heads rubric).

Below we shall only consider two cases of new sets usage in jewelry and small art - for the manufacturing of:

It has to be mentioned that our technologies and equipment may be successfully applied for tacks and pulse arc welds fulfillment during producing and repair rings, thick chains, bracelet hinges and - because of welding-brazing processes using - for the individual or exclusive dental jewelry.

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