how can i make machine like a small spot welding for weld gold and silver ?
98948
All you really need is a source of high current. A car battery would work fine. The real question is what are you going to use as a "rod" and "flux"  Those are the critical issues.
600795
http://www.finishing.com/faqs/howworks.html\n\nI work at place where we send some of our stuff out to be electroplated(nickel, brushed nickel..chrome etc)\nI patinate brass (lighting fistures) with chemecals and torch.(we build antique repro lighting fixtures.
135753
A melting furnace, either arc type or refractory can be built at home, but it is quite the effort. I have melted gold (1845 degrees for 24 karat) in my driveway with a homemade refractory furnace and it took me a lot of effort and practice. Plans for this type of furnace are readily available on the internet. I have also tried aqua regia processing for gold extraction from CPUs and found the effort to be more than the value of my results.
700634
i heard there are tiny metals ranging in size between\nmicrodots and pieces of wire 1/3rd of an inch.
447971
Depends\nI would say a a cast ductile iron piece would work on a small pump and motor assembly .  How ever more info is needed. Knowing the motor Horse power and shaft length. Mainly you are covering the shaft so accidental contact can't be  made by a person,,, But if you are needing it to also protect against flying object if the shaft breaks,,then thats going to change a few things
49343
yes, you can have a jeweler do it\n\nbut i would not recomend it\nreal gold is very soft\n\nthat is why it is hardened with nickel.\n\ntalk to a jeweler and explain what you want.\nyou did not specify if the gold you wanted to cover was pure or an alloy.
399593
Look into a product called Alumaloy. It's like welding that you can do with an ordinary propane torch. They claim its stronger than steel and will bond to any kind of metal.
169774
I use a torch with MAPP guess whenever I solder copper pipes.  For welding iron, I use a MIG or arc welder.
1176756
Time, temparature, and pressure are required to weld metals or polymers together.  Ultrasonic vibration is used as the heat source. Combined with pressure and a little time, it causes the molecules to integrate together resulting in a welded part.
68849
Gold is usally found in veins in mines.  This is after yearssssss of a couple different mixtures that could happen with elements and combounds that get really complicated an messy.  But, scientist have created a particle accelerator that shots atoms at one another to created a desired "pure" element, but this mechine is about the size of a football feild or so and the chamber that the bombarding happens in is a room as big as your average class room and it only produces just enough gold to little dust the tip of a sewing neddle.
125282
Most efficient? If you don't have a lab, then I would assume just doing your best at grinding off the top layer, and trying to melt the shreddings down into a >70% gold alloy. Since gold's melting point is OVER 1000 degrees Celsius, I suppose your best bet is to heat the grindings as much as possible, and then pounding them together into a single mass (like a black-smith...or 'gold-smith'). But you have to realize HOW LITTLE gold is actually on there. The layer is so thin...sometimes merely 2-3 micrometers. You're gonna get a lot of impurities, such as nickel and copper. Gold-plating is usually done on copper or silver; and in the case of copper, a thin layer of nickel is placed below the gold. And since the melting point of nickel isn't that far from that of gold, and copper's is almost EXACTLY that of gold's, you're gonna get a random mixture of crap. I imagine the process is more trouble than it's worth. I'd just go buy gold from alfa aesar or somewhere like that for cheap-as-free.
135823
The three types of welding are 1. Electrode welding, which uses a coated metal filler rod to add metal to the weld puddle; the welding job determines the setting of welder amperage and the type and size of electrode used 2. MIG welding (Metal Inert Gas), also known as wire-feed welding, which is a semi-automatic process and the easiest of the three to learn; it uses an inert gas for shielding 3. TIG welding (Tungsten Inert Gas), also known as heliarc welding, which uses a tungsten electrode shielded by inert gas. TIG is slower than MIG and is more precise, which is why it is used for thinner and more exotic metals.
315423
all welding uses a heat source to melt the parent metal, parent metal is the metal you are trying to weld.\nWhen the metal melts, it can absorb gas from the air. This is not good, oxygen causes corrosion and hydrogen creates bubbles is the metal which weakens it. So when you weld you need to doo something to keep these gases out.\nOxy-acetalence or oxy-l.p.g. welding uses a gas flame to melt the paretn metal. The ratio of oxygen to acetalene or l.p.g. is critical for burning cleanly and not get oxygen in to the weld. Additional metal is applied by a filler wire, dipped in manually by the person welding.\n\nM.I.G. and T.I.G. use an inert gas (the I.G. in their name) to keep the other gases out.\n\nStick welders (manual metal arc) uses the flux around the welding rod to create a suitable atmosphere around the weld pool.\n\nmig, tig and arc use an electric current to melt the parent metal\n\nwith mig, the machine feeds extra metal in to the weld the whole time.\n\nwith arc the welding rod supplies extra metal\n\nwith tig the operator adds filler wire manually as required.\n\nTig does the nicest welds but it the most expensive as it is slow.
835302
TIG welding uses argon gas and a very hot electrode to essentially melt two metals together. MIG welding uses a wire fed filler to fill the space in between to pieces of metal.
531203
prooly need ifrared thingy\ntry a industrial magnet
184708
Well obviously it has to be a production line, so the only way you could do it is several machines in a row that bend each link a little more at a time forming a near full clamp, then it would piece them together and run it through a final one to  seal them and weld them together... maybE?
513117
use a potato and two different metals as electrodes. The link will help you, do your own homework, or web searching atleast! it was the second link in google for g** sake!