Antikythera Fragment #7 - Ancient Tool Technology - Precision Soft Soldering

g'day chris here and welcome back to clickspring I'm in the process of fastening the curbs to the main plate of the Antikythera mechanism these are the curved metal strips that help to stabilize the larger rotating assemblies three underneath the main solar drive wheel were held in place with pins but the remainder were held in place with soft solder the scan of one join in particular shows the full extent of what was achievable at the time a thin layer of solder that is for the most part run quite well throughout the join and it tells us a great deal because although the tools and materials may have evolved the requirements for a good solder joint were exactly the same 2,000 years ago as they are today above all the joint surfaces must have been clean of contaminants a flux of some description was used to allow the solder to wet the metal surface the joint was fabricated to be closed to allow the capillary force to draw the liquid solder inside and for the solder to flow easily the part of the surrounding area must have been raised to a temperature somewhat above the solder melting point now the main plate of the mechanism is a substantial heatsink and for the most part the components are unrestrained and so easily knocked out of position so it's clear that the maker had a means of applying substantial heat to a specific work area that also permitted gentle application of the solder and the challenge is to achieve the same result using the tools and materials known to have existed at the time so starting with the heat source the ancients had considerable experience working copper and well understood its properties so I think it's likely that the hot tools were indeed made from copper and in all likelihood resembles what we were described as an old-school soldering iron the solder may well have been applied using the tip of the bit but the nature of the parts suggests to me that the bits were probably just the heat source and that the solder was more likely touched into the join from the side so after a bit of testing I've settled on a collection of old-style copper bits along with some larger copper blocks the smaller bits allow me to more precisely direct the heat where it's needed and I've made them quite long and narrow to reach down inside the small gaps between the blocks the blocks are larger and so act as a broader heat source to raise the temperature of the general work area they can also be left cold and so act as a heat sink to protect a part that's already been soldered into position now I've mentioned in previous videos that I think abrasives played a big role in the construction of the mechanism in this case I'm using powdered pumice on a damp cloth to reveal fresh metal but it's not enough to simply clean off the surface and leave it at that as the metal is heated oxides quickly reform on the surface and work to repel the solder it sits on top of the oxide layer as a sort of paste and now a man of heat will make it flow on the metal underneath so in addition to being clean a flux is required to chemically reduce the oxide and allow the metal to wet the surface and there are two types of flux to consider passive and active the classic active flux is a dilute zinc chloride solution formed from hydrochloric acid and zinc otherwise known as killed spirits now the use of killed spirits can be traced back many hundreds of years and so today we consider it to be quite traditional but I've yet to find a source establishing its use as far back as antiquity so despite it being an excellent flux for now I'm leaving it out of contention of the passive fluxes tallow is well documented as being used in the period but I think the more likely contender is rosin otherwise known as Greek pitch or by its regional name of colophony rosin would have been readily available during the period of the mechanisms construction and it's a superbly effective flux still in widespread use today it also has the benefit that it's easy to work with and control with the gentle heat it can be manipulated into a convenient shape for ready application to the work area and the last material to consider is of course the solder now we don't know the exact composition of the alloy used in the mechanism but the radio dense nature of the join suggests a lead-based solder and I think a 60/40 10 led alloy is a reasonable starting point again the charcoal fire can be used to heat the raw components until molten and it's easily solidified into conveniently held shapes for later use ok so that's everything required time to give it a go and see how it all performs I'm using a naturally aspirated charcoal fire to heat the tools and the first thing to mention is just how labor-intensive and resource hungry it is it takes a lot of time and charcoal to get the tools to the required temperature and it takes a fair amount of work to keep the fire well tended and hot of course the heat immediately starts to leave the tools as soon as they're removed from the coals so I found I needed to work fairly quickly to get the best results and also that planning the sequence of events was important everything needs to be close to hand to keep the process flowing and make the best use of the heat for the larger pieces it also helped to break the job into two parts first by heating up the plate enough to flow the rosin and then dropping the part into its general position at this elevated temperature the rosin stays tacky for a few minutes allowing a more careful positioning of the part after which the hot tools were returned to run the solder into the join now there's no doubt that this is a very different way of working compared to the modern process but for all the differences it's the similarities that are the most striking because no matter the tools or methods used it all still comes down to seeing that tiny flash of silver as the solder runs around the scene indicating a good join somewhere in the distant past either by accident or design someone saw that flash of silver and recognized its potential the process of how to best make it happen was mastered and then passed on until it eventually became part of the workshop tradition that led to not just the Antikythera mechanism but also much of the technology that followed it so that even now thousands of years later soft solder remains one of the easiest and most common methods for joining metal thanks for watching I'll see you later

Channel: Clickspring

Views: 908,632

Keywords: Antikythera, Antikythera mechanism, soft solder, soft soldering, soldering, ancient greece, clickspring, rosin, solder, flux, rosin flux

Id: T_MdxdGr57k

Length: 7min 36sec (456 seconds)

Published: Sun Sep 16 2018

Reddit Comments

[u/Dtnoip30]

To get an idea of what the Greeks and later Romans could do in terms of complex machinery, this description of a Byzantine Emperor's throne room is fascinating:

In front of the emperor’s throne was set up a tree of gilded bronze, its branches filled with birds, likewise made of bronze gilded over, and these emitted cries appropriate to their species. Now the emperor’s throne was made in such a cunning manner that at one moment it was down on the ground, while at another it rose higher and was to be seen up in the air. This throne was of immense size and was, as it were, guarded by lions, made either of bronze or wood covered with gold, which struck the ground with their tails and roared with open mouth and quivering tongue. Leaning on the shoulders of two eunuchs, I was brought into the emperor’s presence. As I came up the lions began to roar and the birds to twitter, each according to its kind, but I was moved neither by fear nor astonishment … After I had done obeisance to the Emperor by prostrating myself three times, I lifted my head, and behold! the man whom I had just seen sitting at a moderate height from the ground had now changed his vestments and was sitting as high as the ceiling of the hall. I could not think how this was done, unless perhaps he was lifted up by some such machine as is used for raising the timbers of a wine press.

[u/[deleted]]

Clickspring is definitely some of the best content on YouTube.

[u/bmwhite3]

That was really interesting and oddly satisfying to watch!

[u/LizardAscension]

This brought me down the rabbit hole of what this device was used for. If you want to learn more about the Antikythera Mechanism , this is a good documentary:

https://www.youtube.com/watch?v=jSQNEPbQOiI

[u/Imitation88]

If you all enjoyed this it's definitely worth checking out the rest of his channel. He's currently working on recreating the antikythera mechanism using mainly ancient techniques, watching him hand cut teeth on gears is fascinating to me.

Doesn't put out a ton of content but it's always a pleasure seeing a new video of his pop up.

[u/jdemack]

Im a sheet metal worker. We still use this process today. Except we use acetylene or propane to heat our irons up. And it's still a tin led combo for the solder. It's good for joining seams of copper roof and flashing to keep water out way better than caulk.

[u/rasmus9311]

He makes it look so easy!

[u/WittyNameNumbers]

Always interesting to see the tech that ancient civilizations came up with.

[u/toinfinityandbeyondo]

This is a great video and I never really knew why flux was used. I knew it’s to prevent oxidation but didn’t know it helps with wetting the surface so that the solder sticks....is this the same concept for why flux is used in welding tho?