Sword in the rock - make it last the ages

Question

Merlin the wizard has a problem.

Sure, it was a piece of cake to move forward in time to the 21st century, procure a sword that was made with the highest 21st century standards, go back in time, and stick it in a pile of cement. The sword's handle, of course, is imbued with DNA detectors and personality divining spells that will retract the perpendicular spikes at the tip of the blade, allowing he whom the wizard deems worthy to slide the blade out of the rock.

So Merlin looks at his handy work, smiling with satisfaction, but as he turns to go a thought pops up -

How can he expect the sword to last through the ages? Sure, 21st century grade steel is tough, but will it survive centuries in the British outdoors?

Merlin turns back in alarm, sighs and starts working on making the sword last.

What should he do? He's a wizard and uses magic, sure, but I'd like to minimize the handwaving, so pointing out specific changes that Merlin would make to the environment will be appreciated. Also, he's no engineer and would rather minimize the use of technology for this, but he does have limited access to 21st century tech (mostly stuff that he can buy/pay someone to make for him, but he can't bring people back in time to help).

Also - For how long can he get the sword to last (how long in the past can Merlin go to start the sword-in-the-rock legend? The longer the better, as ancient legends go)

Ye olde EDIT the 1st: to avoid being too story based I'll rephrase: Set in our world, wishing to minimize handwaving, what minimal changes to the environment around the sword (weather, terrain, maybe society, etc.) would prevent the sword from corroding or breaking, for as long as possible? Said changes should be explained in as scientific a way as possible, but I'm not looking for diamond-hard science, just a few paragraphs to explain to the readers how the sword lasted for as long as it did.

Ye olde EDIT the 2nd: The blade will be steel or some steel alloy. The sword will be used in combat and needs to be stronger than other swords. The idea is to have something close-to-but-somewhat-better than middle ages swords. A lot of answers go for an all powerful material, but if I do that, it might as well be Adamantium that cuts through walls and shoots fireballs. Minimimalization is what I'm looking for (treks in time not withstanding).

Answer 1

Merlin knows about metallurgy, and will place in the immediate surroundings of the rock (or even IN the rock) a sacrificial anode made of magnesium, aluminium, zinc or another suitable metal.

A galvanic anode is the main component of a galvanic cathodic protection (CP) system used to protect buried or submerged metal structures from corrosion.

By simply replacing the anode from time to time he can ensure that the sword will last over the centuries.

Answer 2

Make the Legend last through the ages

So, Merlin telemagicks to 5000 years ago, presents the sword-in-cement LEGEND to some fancy king. Then he rigs up some scenario where the sword is found. People try and fail to remove the sword, the legend spreads.

Merlin then causes some event (flood, landslide, magic POOFing, etc) to disappear the sword. The sword is gone but the legend lives on.

The sword didn't actually disappear, but Merlin simply moved forward 1000 years to do the same thing. This time it's not a new legend, but a confirmation of an old legend. People try, fail, sword disappears after a while again.

Merlin lather/rinse/repeat's a few times, and now you have a sword that has "existed" for 5000 years, but with only the wear and tear of a month or two.

Answer 3

Can there be hereditary Servants of the Sword? These folks would live nearby, working the earth etc but they take responsibility for periodically going out to visit the Sword and putting a fresh coat of grease on it.

Maybe they could have special hats - worn only for the sword greasing, you know.

Answer 4

Let it rust.

Seriously. A thick chunk of steel is already going to last ages without any special treatment. It will corrode on the outside for sure, but this adds to the authenticity of just how old it is. Maybe build a gazebo over it to keep the absolute worst of the weather off.

It'll be way more exciting when "he whom the wizard deems worthy" finally shows up - not only are they able to pull the obviously ancient sword from the stone, but the "personality divining spells" can trigger a spell to instantaneously restore the sword to its original, pristine condition in a fantastic display of light/sparks/electricity/whatever. This would cast aside any doubt from onlooking skeptics that the bearer truly is someone special.

Answer 5

If he has figured out time travel why not just have him put it in a time-loop. At the start of every day the sword is returned to the condition it was in when it was first placed into the stone.

Or you could go as far as to put the entire location of the stone into a time-loop (presumably a sacred grove or hilltop), thereby removing any possible deterioration due to weather/time. It would also allow the grove to retain the season it was in when the sword was placed, which would serve to feed the legend as the grove is perpetually the same every day regardless of the time of year.

Answer 6

Similar to Josh's answer:

Use time manipulation to actually halt the flow of time for the sword and stone. This solves a couple of issues. The sword won't rust, the stone can't be chipped away and no one can remove the sword until the chosen one touches it and removes the time stop spell.

Of course, if I lived nearby, the young Arthur would have to gain access to my wood mill that I built around a length of blade that never dulls no matter how many logs I split by forcing them against the blade....

Answer 7

As KOZM points out, stainless steels exist now, and you can source one for this purpose. Let me be more quantitative and list specific examples, based on current knifes for sale.

In particular, the alloy used for Wüshhof kitchen knives is extremely stain resistant. It’s rather soft, though, which makes for a flexible blade but needs constant honing. This is called DIN X50CrMoV15, or material number (W-Nr standard) 1.4116. It is 0.5% carbon, 15% chromium, with a pinch of molybdenum and vanadium.

Knives can be made of vanadium steel, which gives the same stain/tarnish resistance as stainless steel but without sacrificing so much hardness. This uses more vanadium in place of chromium. I have an every-day carry folding blade made from VG-10, and Wikipedia has a list of steels they have experimented with. VG-10 is hardened around RC60. It is also used to make swords!

They also make knives using CPM, which is a powder metallurgy and is fascinating to look into.

CPM-S90V (a.k.a. 420V), similar to Crucible's S60V but designed to be more wear resistant with a very high carbide volume and high vanadium content. Appreciated for extreme edge-holding. S90V was featured in a sprint run of Spyderco's Military in 2008. Since then it has been used in several sprint runs in knives like the Manix 2 and Paramilitary 2. While S90V holds an edge significantly better than S30V, both are usually hardened to about 59-61 RC.

So you can buy steel today that might easily last that long without any special protection! Add to that a final chrome plating, a passivation treatment, and a coat of turtle wax, and Merlyn’s magical ability to keep humidity away from the artifact will hardly be needed. Stainless steel will last for hundreds of years without this final preparation.

Answer 8

Merlin picked up more than some cool tech in the 21st century. He picked up our consumer society's attitude.

Why bother protecting or repairing the sword? There was a great deal going on bulk-buy swords.

Just pop back in time to when he first wants the sword, and then travel forward in small increments, replacing the old sword with a new one each time.

Edit, obviously the DNA sensor needs to activate for his DNA as well as the rightful King's.

Answer 9

There are plenty of alloys, particularly "stainless" steels that temper well and passivate on the surface, and would last many centuries; plate it with gold or other noble metal to give it even more life and spruce it up.

Answer 10

Just use titanium. (An alloy of it, really.)

The question implied Merlin wanted the best 21st century standard and that is what NASA and, well, everyone, really, uses when they want something that works like steel but better.

Important points:

Expensive due to the refining being energy intensive, but is otherwise common material and easily available. Merlin could just buy the sword and while it would be expensive and a custom job, it would not require miracles.

More or less works like steel. Titanium has no weird failure modes that make it instantly shatter or dissolve like some other metals have. You can usually replace steel with it and trust it to work.

Almost instantly forms hard and thick layer of titanium oxide on its surface when exposed to air. Because of this titanium is a highly reactive metal that is nearly immune to corrosion in practice. It can be used in sea water or even dilute acid. Embedding it in a stone should not be an issue.

Titanium has superior strength to mass ratio. The sword would not really be stronger than a sword made of best steel alloys, but it would instantly feel magical due to its lower weight. And lower weight actually matters with swords. Alternately you can keep it weighing the same as normal sword, but make it much harder to break. Or any combination in between.

Titanium is also attractive and has been used for jewellery and statues. A sword made from titanium would probably look better than one made from steel.

Answer 11

The sword is a sword, albeit an exceptional one. Let's preserve it as such, since it needs to function as a sword. But the stone is no mere stone. It is actually a machine that maintains the sword, disguised as a stone!

This method allows you to imagine a simple, feasible, and mostly sound scientific mechanism, hidden inconspicuously in something innocuous - as to not pollute history. It is likely the sword will be scrutinized, but the stone may be overlooked. Too advanced for the middle ages, the people would be less likely to anticipate that a stone is not what it appears. Like the stone-facade speakers many people use in their gardens, they can be made to look nearly identical to an actual stone (if not a real hollowed stone) and house a complex machine. Merlin could commission one that includes sharpening, drying, shining and any other capability that would ensure the sword would last indefinitely with the correct tooling, materials and power source (several other answer propose some of these components). With this machine, the legend could be set at its maximum time.

This should meet all your requirements simply and cleverly. It accounts for the preservation of the sword, and can additionally be used to include the mechanical ability to wait for the correct owner. It also avoids any corruption of the sword's structural or historical integrity. Where in a sword do you put a complex biometric scanner and sci-fi "personality analytics" software? How would it affect its functionality, strength, weight, and balance? A stone could be enormous both in what's exposed and (like an iceberg) what is in the ground. It has one purpose and would not have any other effects on the story other than a sound scientific explanation of how the sword is housed, maintained and dispensed.

Hope this helps your story!

Answer 12

Electroplating.

Your sword - it's made of steel for strength and 'swordyness', but ... you can coat it in something that isn't reactive, and it should keep for a good long time.

Steel is the best thing to be using

Gold's the obvious choice - it's nonreactive, and it'll make the sword look 'special'. But it's perhaps a bit too obvious (and too obviously 'gold' which is also something that a poor peasant might take a knife to scrape it off).

But something like chromium, will make it still 'steel like' but just really shiny.

Or just zinc - a process known as Galvanization which is something that's still used routinely for ... all sorts of things.

Select electroplating metal according to need. Expect that when the sword is finally used - it'll need sharpening when it finally does get drawn, and day to day use (hitting people covered in steel with it) will ablate the coating. But it'll still be rust resistant, and we can assume at that point, the sword owner is maintaining it.

The lifespan of galvanization is 50-75 years using 'standard' but with a 200 micrometer coating, should be good for around 250 years in a 'benign rural' location.

I can't find a similar lifespan (with a quick bit of googling) chart for Chrome or Gold. But both Gold, or better yet Platinum have extremely low reactivity (lower than Zinc) so I would assume they last considerably longer.

So I would say - go with go with Platinum - it will look good, won't be 'obviously gold' and it will last a very long time.

Reactivity Series

Answer 13

Ancient has a different meaning for people living today than people back then. (~500AD for King Arthur) People living back in merlin's time were generally not literate. Most legends were passed via word of mouth though the generations (which were shorter back then as well) Those who could read typically didn't have access to written historical records, many of which would have been lost during the fall of the Roman empire anyway. I would say that anything before the fall or Rome (~375AD) could easily be considered ancient for people living in King Arthur's time.

Given that women had children young back then, "your grandmother's grandmother's grandmother" could be only 100 years in the past.

Going by this description of merlin, His "time traveling" isn't really time traveling in the regular sense of the word but rather just "remembering the future" and "not knowing the past".

Maybe he can "remember" 21th century steel making techniques to craft the sword without leaving his time. He knows the time when the sword is going to be pulled from the stone as well so now its just a matter of crafting and setting the sword early enough for it to become "ancient legend" if thats only 80-100 years, then it should be easy enough using modern techniques.

Answer 14

Make the sword out of a non-corroding alloy? Or a heavy coat of Aluminium?

The sword out of the stone was only proof of kingship - it wasn't intended to be used in battle. And in some of the legends, it breaks pretty fast so it could be made out of platinum even though you wouldn't want to use it in combat.

Answer 15

Just a thought...

The focus is so much on the sword as a whole, but because the sword is embedded, the blade itself is actually encased and protected by the stone (and therefore not exposed to the elements).

A non-corrosive metal for the handle would be just as effective while allowing a metal that can hold an edge for the actual blade.

Answer 16

You want the sword to have amazing longevity, but not be really that overpowered. That makes sense from a narrative standpoint, but as for actual materials... IANAB (I am not a blacksmith) but it seems tricky to get both, and I can't give you a definitive answer about that. Worry not, though, a workaround comes to mind!

The sword doesn't last more than a regular 21st century sword, but time past differently for it.

Merlin can travel in time, so presumably he could make the sword travel in time. You go to the year 0 (or whenever, 0 is just to simplify the math) and set the sword in stone. Now you program it to constantly jump forward a set amount after a set time.

Let's say you make it so it only stays for the whole month of December and then on January 1st it jumps (in time) to the next December. Then, our 2000 years of History would only mean 2000 months for the sword. If, instead, you set it to only appear one day a month, 2000 years is only 2000 nights wear for the sword.

Not bad, huh? You've extended its "lifetime" and "the sword that can only be found on full moon nights" make for a nifty legend.

Answer 17

IMHO opinion Merlin should build a building around the sword in the stone. The building should have a floor, and the sword in the stone (on top of an anvil if I remember correctly) should be on top of a pedestal that keeps it away from moisture on the floor.

Possibly the building should be designed with many concentric shells and many floors and roofs, with the sword in the stone in the center most room. And perhaps to make it more impressive the building should have domes within domes within domes with the sword in the stone beneath the innermost dome.

No doubt Merlin will have to build robots to repair the building and keep the dehumidifiers running and repair each other and keep thieves out.

I note that many artifacts including swords have been found in water in northern Europe, apparently ritually deposited by Celtic peoples. So apparently iron swords do not rust away into nothing during 1,500 to 2,000 years in the water.

Many bronze items including swords have also been found in dirt or water having survived rather intact for 3,000 years. Thus it might be wise for Merlin to make or obtain a bronze sword for the stone. Iron did not replace bronze because it was better as much as because it was cheaper and more common. So a bronze sword could be as good as an iron sword and maybe more resistant to corrosion.

And maybe gilding the sword before putting it in the stone would help it stay as good as new for decades, centuries, or millennia.

Answer 18

Make the sword travel backward in time...

When you plant the sword it is perfect, but in the past it is getting older and older. This perfectly sets up a legend of a sword in the stone - a mysterious sword which seemed to grow from nothing and was improving in form over time.

Of course, this creates some timeline problems. For instance if you plant it the day after you need it, it would exist yesterday, but if it was pulled from the stone then, it would not exist in the past for the legend to work... So perhaps, you could have two swords, one that travels backwards in time (for a legend) and one that travels forward in time (only needed for a single day) which could be pulled from the stone.

Answer 19

Maybe present The Sword of Goujian . Survived without rusting for 2500 years before being found because the blade contained sulfur which helped to prevent oxidation.

Answer 20

Cast a spell that prevents oxygen (or water) from reaching the surface of the sword, thus preventing oxidation (rust)

Answer 21

This is something of a combination of Scott and Mirror318's answers:

Add a clause to the legend that the sword is super awesome AND can be instantly brought back to a state of full repair (actually replaced) when brought to Merlin or an approved temple or whatever. With a warning of "tempting fate" or something comparable ominous, if this is abused.

And the "sword in stone" is a tough, thick ingot meant to be "restored" shortly after, and made/enchanted specifically for the purpose of withstanding the elements and human ingenuity.
And don't underestimate that last part. Think of someone bringing siege engine - class machines to dust the rock and replace the Gordian Knot legend.

Answer 22

Use a porous stone, envelop it in something oil-tight, saturate the inner porous matter in some stable oil (shouldn't go rancid or polymerize ).

Obviously, still provide a mechanism to make sure the well lubricated sword isn't trivial to slide out :)

Oil-soaked paper is nowadays still commonly used to package, store and ship non-stainless tool steel items...

Answer 23

Do we know whether whole blade was stuck in the stone or just a part of it?

Suppose whole blade is emerged in the fake-solid stone. There is a hollow full of synthetic oil to suppress any degradation of the blade.

There is a bayonet mount disguised decorative-magic engraved symbols and it contains pure gold ring which serves as metal sealing. The bayonet is connected to the DNA detector and releases the sword at appropriate time. There are also rubber, viton or silicone blades just to remove the oil when the Chosen One (TM) pulls the sword out.

Therefore the only part of the sword to face the ages is the handle. Luckily for Merlin there is a plenty of commercially available surface treatments to enhance the oxidation resistance and appeareance.

There is hot bluing and black oxidizing finish which gives the oxidation resistance (oxides usually do not oxidize) and dark blue-black matte finish. Thin film of TiN will give the oxidation resistance and gold finish, TiAlN will give purple finish. He can also look for TiO2 film which can be superhyrophilic and when illuminated by UV light it can clean itself from bacteria and algae. Merlin can also look for rare-earth metal oxide coatings which can provide hard and superhydophobic surfaces.

Answer 24

The sword is actually made from a substance that is more like fiberglass than traditional metallurgy would see; the blade has been infused with carbon nanotubes, which is part of what makes Excalibur so strong.

The nanotubes actually poke out of the surface of the steel blade, and therefore microscopically Excalibur is extraordinarily bumpy, which grants it an incredible property: it is ultrahydrophobic; water just cannot stick to it because it would rather stick to itself. In addition the surface might also be antimicrobial for the same reason; it might shred apart microorganisms that try to live on it. As a result, the cracks might be capable of holding oily molecules for a very long time, so that they also keep oxygen atoms themselves at bay.

The main place where this may not work (due to ages of wear and tear eventually eroding the nanoscale surface away) is the handle, which is coated with a thick layer of gold and therefore does not corrode in the first place.

Just to make sure, the "sword in the stone" is actually stuck into a cliff face inside the forest -- Merlin has bored a large hole into a small rocky cliff, leaving a large bump in the center where the sword has been stuck. The space functions as a natural shelter, keeping the usual moisture and rain at bay and also making it impossible for other kings down the ages to install the sword-in-the-stone in their courts as an artistic piece. It is perhaps even raised up many feet above ground level, so that one has to shed one's armor and do some rock-climbing before one can even attempt to pull the sword out of the stone, so it is more a pastime for young kids than for serious knights.

Answer 25

How about having the sword appear for some significant annual event- one day only each year. With time travel, Merlin can soon build up a long history. The sword could be fixed into the stone by a modern adhesive, such as an epoxy that protects the blade. Merlin can release the blade at the right time by some simple heat magic that causes the adhesive to break down- at a temperature that does not harm the steel.

Answer 26

If he can go a bit further into the future, then nanites are the obviously choice.

Either everything is made of nanites or maybe just a thin layer in the stone. They constantly refresh the surface, and consume the stone for energy and materials.

A bit more realistic, maybe graphine.

Answer 27

Check when the sword was destroyed before going back to place it.

Making a sword last the ages sounds easy. The problem is, everybody has heard this story about how the person who pulls it from the rock is the true King. And every King who rules over that rock is staring, balefully, at a seditious sword that is telling every filthy peasant that looks at it that he is not the True King. That won't abide.

So this sword needs to be proof, not just against the rain and snow, but against teams of horses, thumbscrews, cannonballs, monster trucks maybe (depending on when the sword was meant to be claimed). Worst of all, it faces the metal file, wielded by a tremendously strong and dutiful slave whose life depends on meeting a deadline. If that fails, the King can simply have the entire hilltop removed and hauled on a massive barge out to sea.

So Merlin travels forward in time after he places the sword until it is destroyed. Then he sends himself an instant message that arrives right before he went back with the sword, telling him to "go back to this time instead". So Merlin actually takes the sword (the one original sword he made up, there is no other) back to that time and puts it in place, and then he goes forward until the sword is destroyed, and sends himself an instant message received a few moments before the IM above would have been received.

Obviously Merlin goes back only once, to the very latest time when the sword was seen to appear, taking the only copy of the sword, and is pleased on shifting back forward to see the rightful King claim it. All the other times it has been seen, all the mad false Kings trying to dissolve it in aqua regia or melt it in a blast furnace, only to see it reappear -- that is just dead history, which he has done nothing to change.

Answer 28

He doesn't, obviously.

He can time travel, so instead of bringing back a sword from the 21st century (what an odd time period to pick to locate a sword in, by the way), he brings back a planetary annihilator from the 31st century. Much more effective choice than any sword. Seriously, the idea of time travelling to bring back a sharp hunk of metal is beyond absurd.

But he's a magician, so he doesn't need time travel, he uses magic. A spell of "remove moisture" or "prevent rust" envelopes the sword, keeping it in pristine condition throughout the ages. You're way-overthinking the story about a magical sword and the person with the magical ability to remove it from the stone that's magically holding it.