 I can still see it today.
Copper electrodes are a must. I’ve never seen a spot welder without them. Also, there needs to be some way to adjust the voltage as the thickness of the metal being welded I doubt would be consistent. Some way to clamp the electrodes in place and a foot pedal switch to fee up your hands to hold the pieces being welded is also necessary. Depending on the voltage and current being used, an NO SCR triggered by the foot switch would be ideal, Depending on the current, though, a two pole Mercury relay would be a safe bet. Just be sure to make a snubber if you’re using any microprocessor circuitry to control the voltage/current.
Banging together two copper blocks is not only bush league but dangerous.
I believe he’s using graphite electrodes because he’s welding copper. Wouldn’t make much sense to me to use copper electrodes to weld that. That said, copper works great on steel.
Instead of making 2 carbon electrodes he could have just went to a welding store and bought a pack of carbon arc gauging electrodes which are the exact same same thing he built, but they’re made to a higher standard.
Old arc welders had a “copper gouging electrode” available, it is graphite inside a copper tube. He wouldn’t have to build his.
Why would you wire capacitors in series. that will only lower capacitance. {1/C+/C(n+1)}^-1 this is dump. make a real arc wielder. use a car battery charger or something and some graphite.
It lowers the capacitance as seen from the ends of the series, but he’s charging the capacitors in parallel.
Plus, the energy of the discharge doesn’t change, because at the same time the energy stored in the bank increases at the square of the voltage.
Since the equation for ENERGY storage is 1/2CV^2…you get more bang out of a potential voltage increase. A good analogy is momentum where capacitance is mass and voltage is velocity (1/2mv^2).
With that said, I have always connected them in parallel because in this application, lower voltage is advantageous.
They store the same amount of energy if they are hooked up in series or parallel, you forgot to decrease the capacitance in your formula for when they are connected in series. They are connected in series so that it can deliver more current faster; like 600F of capacitance is probably overkill for this project.
TIG works well for welding titanium. Not sure it fits your definition of cheap though.
I have worked on several spot-stud welders that are capacitive discharge. These are the welders that weld the little threaded studs or standoff that you see in metal cases and electrical enclosures.
They used two large electrolytic caps, probably about 400v, they were unmarked so I don’t know the capacitance. An adjustable voltage regulated doubler circuit controlled the charge voltage to the caps setting the weld power. I think maximum was around 250v. A large hockey puck style SCR was used to discharge the caps into the work. Very simple and reliable.
The devil is in the ultracap detail. They are hard to get by and expensive. Questionable whether its worth the effort if one can just built a regular one for steel.
Is hackaday ever going to post an update to the microwave transformer spot welder project from over a year ago? A controller circuit was promised, but never delivered.
It seems that just buying the proper tools and safety equipment would be cheaper (and safer) than buying / hooking up these capacitors — unless he like got them as used surplus from Tesla’s dismantled death ray.
I doubt these ultracaps are rated for such massive discharges. Low ESR is one thing but kiloamps will kill the bonds on the inside.
 I got some answers for some recurring/related questions you guys have asked.
I went with ultra caps because they were actually cheaper (about $10-15 ea. surplus), smaller, and I thought more durable. I understand they were pulled from electric bus systems, so I figured they were designed for running at high power. Plus they’re rated for millions of charge cycles, unlike batteries.
The banging blocks technique is obviously a bit, um, unorthodox, but it’s extremely robust. As Haku mentions, MOSFETs and the like can fail catastrophically; I have a hard time imagining my copper brick doing the same. Ultimately, a proper MOSFET switch with a 555 pulse timing circuit is probably the way to go, but requires a hefty bit of planning and thought.
The motivation for this project was simple- a group I work with needed a way of connecting copper tabs. When it seemed that all commercial systems cost $10k+, I scrounged $50 and built this thing in a couple hours as a proof of concept, nothing more.
In the end, I think I’ve stumbled across a quite useful method for welding copper- there are obvious flaws in the execution, but the central premise works rather well.
I think it does extend a bit beyond fast food, albeit not extremely far. Different areas in America have relatively popular regional dishes. I know the case of Barbecue has already been mentioned but damn the American South has some of the best damn food on Earth if you can put up with all the hicks who live there. 
THE VIRUS TRIAL
Measles virus put to the test. Dr. Stefan Lanka wins in court…
Dr. Lanka meets the press
Since the early 1990s, German biologist Dr. Stefan Lanka has been at the forefront of challenging the medical theory stating that viruses are the cause of
infectious diseases
such as hepatitis,
AIDS
, the
flu
,
polio
,
herpes
, or
measles
.
Caroline Markolin
has presented Dr. Lanka’s activities in her lecture video “
Virus Mania
” in great details (watch
Part 2
of the recordings on this website – starting at
08:08
).
Based on his studies in virology, Dr. Lanka discovered that viruses are vital components of simple life-forms that do not exist in complex organisms such as humans, animals, or plants. His research shows that the viruses believed to cause “viral infections” are in reality ordinary cell particles that have been misinterpreted as constituents of the viruses in question. Dr. Lanka also determined that viruses don’t have a destructive effect on the host, as commonly believed. These findings are in full accordance with the discoveries of
Dr. Ryke Geerd Hamer
who demonstrated already in the 1980s that contrary to the standard theory, microbes do not harm the organism but play instead a supportive role during the healing process of diseases (see
Fourth Biological Law of the New Medicine
)..
Here is a brief overview of the court proceedings:
On
November 24, 2011
, Dr. Lanka announced on his website that he would offer a prize of € 100,000 to anyone who could prove the existence of the measles virus. The announcement read as follows: “The reward will be paid, if a scientific publication is presented, in which the existence of the measles virus is not only asserted, but also proven and in which, among other things, the diameter of the measles virus is determined.”
In
January 2012
, Dr. David Bardens took Dr. Lanka up on his pledge. He offered six papers on the subject and asked Dr. Lanka to transfer the € 100,000 to his bank account.
The six publications are:
1. Enders JF, Peebles TC. Propagation in tissue cultures of cytopathogenic agents from patients with measles. Proc Soc Exp Biol Med. 1954 Jun;86(2):277–286.
2. Bech V, Magnus Pv. Studies on measles virus in monkey kidney tissue cultures. Acta Pathol Microbiol Scand. 1959; 42(1): 75–85
3. Horikami SM, Moyer SA. Structure, Transcription, and Replication of Measles Virus. Curr Top Microbiol Immunol. 1995; 191: 35–50.
4. Nakai M, Imagawa DT. Electron microscopy of measles virus replication. J Virol. 1969 Feb; 3(2): 187–97.
5. Lund GA, Tyrell, DL, Bradley RD, Scraba DG. The molecular length of measles virus RNA and the structural organization of measles nucleocapsids. J Gen Virol. 1984 Sep;65 (Pt 9):1535–42.
6. Daikoku E, Morita C, Kohno T, Sano K. Analysis of Morphology and Infectivity of Measles Virus Particles. Bulletin of the Osaka Medical College. 2007; 53(2): 107–14.
Dr. Lanka refused to pay the money since in his opinion these publications did not provide adequate evidence. Subsequently, Dr. Bardens took Dr. Lanka to court.
On
March 12, 2015
, the District Court Ravensburg in southern Germany ruled that the criteria of the advertisement had been fulfilled ordering Dr. Lanka to pay up. Dr. Lanka appealed the ruling.
On
February 16, 2016
, the Higher Regional Court of Stuttgart (OLG) re-evaluated the first ruling, judging that Dr. Bardens did not meet the criteria since he failed to provide proof for the existence of the measles virus presented in
one
publication, as asked by Dr. Lanka in his announcement. Therefore, Dr. Lanka does not have to pay the prize money.
On
January 16, 2017
, the First Civil