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efreysson
02-10-2014, 06:52 PM
I'm writing a story where an undead monster has hibernated in a metal coffin for three hundred years. I need to decide what it's made of. What metal can stay buried in the ground for so long without significant damage, and is also light enough that a small group of people can carry it?

Note, the setting is pre-industrial.

waylander
02-10-2014, 07:01 PM
Lead fits the bill except for people carrying it. The Romans used lead coffins for the burial of important people and they have survived into the modern era.

T J Deen
02-10-2014, 07:02 PM
I'm writing a story where an undead monster has hibernated in a metal coffin for three hundred years. I need to decide what it's made of. What metal can stay buried in the ground for so long without significant damage, and is also light enough that a small group of people can carry it?

Note, the setting is pre-industrial.

people have been using Pewter since before Roman times. When you said coffin it was the first thing to pop in my head as many religious artifacts are also made from pewter.

Telergic
02-10-2014, 09:45 PM
I think pretty much any substantial amount of any common metal can stay buried for hundreds of years without significant damage. I believe even pig iron wouldn't rust completely, even in moist aerated soil, as according to my reading it tends to rust superficially very quickly but the rust doesn't get all that deep into the material. After all, cannonballs and cannons and other iron and steel artifacts more than 300 years old are often recovered from the ocean, which is a lot more corrosive than most soil. Small parts and fine details might corrode or rust beyond recognition over time, but large structural objects made out of metal would last a very long time.

I think the least dense metal available in ancient times would be zinc if the weight of the thing is an issue, but it wouldn't be a huge difference from iron, bronze, etc.

NeuroGlide
02-10-2014, 09:51 PM
There is a rare, exotic metal from pre-industrial times that would fit the bill, worth more than gold by weight. Royalty had plates made from it to show off their wealth.

Aluminum.

Oh sure, it's common now, but we can refine it. Natural pure aluminum is extremely rare.

Drachen Jager
02-10-2014, 09:58 PM
Brass and bronze both last really well and were among the first metals smelted by humans.

Really it's mostly just the ferrous metals (iron, steel) that rust away to nothing. In most other metals the layer of oxidization is non-porous, so they last very well over time. Brass is known to be exceptionally good and it's fairly strong which is why it has a long history on ships and boats.

Telergic
02-10-2014, 10:09 PM
There is a rare, exotic metal from pre-industrial times that would fit the bill, worth more than gold by weight. Royalty had plates made from it to show off their wealth.

Aluminum.

Oh sure, it's common now, but we can refine it. Natural pure aluminum is extremely rare.

Aluminum was first isolated and identified less than 300 years ago, unfortunately. Same for magnesium, another lightweight metal. But both are possibilities if the story is set in the future or on some other world that is reasonably advanced, at least to 19th century metallurgy.

King Neptune
02-10-2014, 11:44 PM
Aluminum and bronze are the best choices. If it is just a thin layer of metal on a wooden box, then you might go with gold. If you are refusing aluminum, then it would have to be bronze or gold foil.

efreysson
02-11-2014, 12:07 AM
I appreciate the answers.

Hmmm. Which weighs more, bronze or pewter, and which is stronger?

Telergic
02-11-2014, 12:14 AM
Let's see, what would it weigh?

Say a minimally-sized coffin has 8 square meters of paneling, say it's 0.5 cm plate. So .04 cubic meter of metal, or 40,000 cubic centimeters. Zinc is 7.14 g/cm^3. So that's 280+ kilograms. Add another 50 to 100 kilograms for the vampire inside, and you've got a heavy but feasible load for 6 people to carry the sort of distance you'd expect from pallbearers.

I just looked it up for fun, so FYI various types of pine and other light woods range from 3 to 5 g/cm^3, while, oak is more like 7 to 9, or even denser than many metals. Of course the material strengths differ, too.

King Neptune
02-11-2014, 01:18 AM
I appreciate the answers.

Hmmm. Which weighs more, bronze or pewter, and which is stronger?

Both are alloys that can be mixed differently, but as a general matter bronze would be stronger, and tin pewter would weigh less, while lead pewter would weigh more.
Bronze: 8.5 g/cm³
Tin Pewter: 7.28 g/cm3
Lead Pewter: 11.34 g/cm3

Steve Collins
02-11-2014, 06:29 PM
If you want something less known and exotic how about Beryllium?
http://beryllium.eu/about-beryllium-and-beryllium-alloys/uses-and-applications-of-beryllium/

Telergic
02-11-2014, 08:36 PM
If you want something less known and exotic how about Beryllium?
http://beryllium.eu/about-beryllium-and-beryllium-alloys/uses-and-applications-of-beryllium/

Again it was discovered less than 300 years ago.

ULTRAGOTHA
02-11-2014, 10:45 PM
Be aware that "pewter" before the 1970s was mostly tin with some copper and lead. I doubt they'd have made a coffin of it. Its also a very soft metal.

Lead would be far more common. Or, more probably, lead lined wood. An entire coffin made entirely of lead would distort its shape over time and be heavier than a lead-lined coffin. Lead is very soft and heavy but a small group of people could move it anyway--say 6 or 8 people. Fewer if you have a cart and oxen.

King Neptune
02-12-2014, 12:00 AM
And three hundred years ago pewter was partly lead.

benbradley
02-12-2014, 12:43 AM
There is a rare, exotic metal from pre-industrial times that would fit the bill, worth more than gold by weight. Royalty had plates made from it to show off their wealth.

Aluminum.

Oh sure, it's common now, but we can refine it. Natural pure aluminum is extremely rare.


Aluminum was first isolated and identified less than 300 years ago, unfortunately. Same for magnesium, another lightweight metal. But both are possibilities if the story is set in the future or on some other world that is reasonably advanced, at least to 19th century metallurgy.
The story of the creation and loss of (the "formula" for) aluminum in the first century AD is told in the first chapter of "Abundance, freely (in exchange for your email address) downloadable here:
https://www.abundancethebook.com/sneak-preview/

A little more googling online research find substantial doubt in the veracity of that claim:
http://cosmoquest.org/forum/showthread.php?59843-Aluminum-Discovered-2000-years-ago&

Maxx B
02-12-2014, 12:47 AM
I'd go for an alloy, something like Billon (silver/copper) would be suitably exotic and well preserved coins have been found dating back to 500 years BC.

Deepthought
02-12-2014, 02:06 AM
I suppose titanium is way too new. Probably an alloy of some type, although as another poster said, aluminium would be very rare. How did Dracula open his coffin? I think a metal lined wood coffin could work.

ULTRAGOTHA
02-12-2014, 07:12 AM
And three hundred years ago pewter was mostly lead.

Back in Roman times pewter was mostly tin. ~70% - 80% tin and the remainder lead with maybe some copper.

Later in the middle ages, we find pewter that is ~90% - 96% tin with the remainder mostly lead and maybe some copper.

Pewter was and is mostly tin. Now-a-days there is no lead, it's tin and some copper.

efreysson
02-12-2014, 10:24 AM
The green patina that forms on bronze, does it form on objects buried in dirt?

Telergic
02-12-2014, 10:28 AM
The green patina that forms on bronze, does it form on objects buried in dirt?

Yes. After a while it turns black. A typical roman aes these days looks like it was dipped in black paint. Mainly just a surface effect, though.

King Neptune
02-12-2014, 04:48 PM
The green patina that forms on bronze, does it form on objects buried in dirt?

Yes, that is copper oxide.

Realspiritik
02-12-2014, 04:59 PM
The important question for metals found in the ground is the location and the burial conditions. Is the ground moist? Is there a high salt content, eg. from a previous seawater flood? Is there oxygen flow, as in a cave? Long-term exposure to salt, water, oxygen, and temperature extremes is hard on all pre-industrial metals and alloys except for gold.

If the box has been buried in a stable, dry environment, you have more choices.

Your best bet for weight is wood (though, again, you'd have to match the type of wood to the conditions). Your best bet for lack of corrosion is gold.

The ancient Egyptians were pretty smart about these things.

Realspiritik
02-12-2014, 05:43 PM
The green patina that forms on bronze, does it form on objects buried in dirt?

Copper has a number of different corrosion products. The green patina you're thinking of -- verdigris -- is caused by a reaction between copper and carbonates, but also chlorides (as from saltwater or sea air) and sulphates (as from acid rain). You can make verdigris by putting copper in vinegar (acetic acid), but verdigris is a toxic compound, so you have to be careful.

The brown/black patina that forms on copper alloys (eg. brass or bronze) is mostly copper oxide.

There's also a green, powdery copper corrosion product formed when copper, bronze, or brass come into contact with chlorides in the ground or in seawater. This is called bronze disease. It eats away at the metal till there's nothing left -- kinda like copper's version of necrotizing fasciitis.

efreysson
02-12-2014, 06:08 PM
Yes. After a while it turns black. A typical roman aes these days looks like it was dipped in black paint. Mainly just a surface effect, though.

Does 300 years count as a while?


The important question for metals found in the ground is the location and the burial conditions. Is the ground moist? Is there a high salt content, eg. from a previous seawater flood? Is there oxygen flow, as in a cave? Long-term exposure to salt, water, oxygen, and temperature extremes is hard on all pre-industrial metals and alloys except for gold.

If the box has been buried in a stable, dry environment, you have more choices.


The coffin is buried in a forest close to a marsh, and the sea.

Realspiritik
02-12-2014, 09:29 PM
The coffin is buried in a forest close to a marsh, and the sea.

Okay . . . these are really bad conditions for the preservation of pre-industrial metals. If a wood case or a stone case wouldn't work for your story, how about the idea of an engineered burial site? A burial site on high ground (for better drainage) with the original soil dug out and replaced with gravel or sand (for better drainage)? Or a stone case around the metal case to protect it?

Could something like that figure in your plot?

NeuroGlide
02-12-2014, 09:57 PM
Okay . . . these are really bad conditions for the preservation of pre-industrial metals. If a wood case or a stone case wouldn't work for your story, how about the idea of an engineered burial site? A burial site on high ground (for better drainage) with the original soil dug out and replaced with gravel or sand (for better drainage)? Or a stone case around the metal case to protect it?

Could something like that figure in your plot?

Actually this might work if it's a peat bog. We've pulled people out of the peat bogs after hundreds of years without decay.

Realspiritik
02-12-2014, 10:09 PM
I have another idea. You could have a metal box (pewter, maybe) that's coated in a thick layer of wax. It would have to be a natural wax (probably beeswax). But a wax coating would give lots of protection, and it's not heavy.

To get the wax off, you'd probably have to heat the box.

Realspiritik
02-12-2014, 10:14 PM
Actually this might work if it's a peat bog. We've pulled people out of the peat bogs after hundreds of years without decay.

Yeah, that's true. Their skin and muscles are preserved, but their bones are completely dissolved because of the acid in the peat.

Peat bogs aren't very friendly to metals for the same reason.

NeuroGlide
02-12-2014, 10:36 PM
Yeah, that's true. Their skin and muscles are preserved, but their bones are completely dissolved because of the acid in the peat.

Peat bogs aren't very friendly to metals for the same reason.

Ok, alkaline lacquer on a rot resistant wood like mahogany, gold foil inlay over all the seams. Sounds like a plan.

Telergic
02-12-2014, 11:07 PM
Okay . . . these are really bad conditions for the preservation of pre-industrial metals. If a wood case or a stone case wouldn't work for your story, how about the idea of an engineered burial site? A burial site on high ground (for better drainage) with the original soil dug out and replaced with gravel or sand (for better drainage)? Or a stone case around the metal case to protect it?

Could something like that figure in your plot?

Do you really think metals and alloys like zinc, nickel, brass, or bronze would be much affected by a mere 300 years in moist soil? Maybe if there is some major-league industrial acid runoff or if the box is made out of very thin plate, but I doubt that ordinary corrosion would do much to the structural integrity of the container in that time.

Realspiritik
02-12-2014, 11:11 PM
Ok, alkaline lacquer on a rot resistant wood like mahogany, gold foil inlay over all the seams. Sounds like a plan.

I want one!

Hoplite
02-12-2014, 11:18 PM
Do you really think metals and alloys like zinc, nickel, brass, or bronze would be much affected by a mere 300 years in moist soil? Maybe if there is some major-league industrial acid runoff or if the box is made out of very thin plate, but I doubt that ordinary corrosion would do much to the structural integrity of the container in that time.

Depending on the acidity of the soil, microorganisms, salinity of water; yes, 300 years could corrode through some metals. I'm not a metal expert. My knowledge is second-hand from my wife (a Ph.D. metallurgist student), and co-workers studying corrosion effects. Modern day brass and stainless steel will corrode in a few years in crappy conditions.

Specifically, they (the co-workers) recently did studies of why sump pumps at gas stations were corroding in less than half the expected life-time: it was bacteria.

Telergic
02-12-2014, 11:44 PM
I suppose it must depend on the metal and the soil. Even small bronze items like coins can be recovered intact except for surface corrosion after thousands of years underground.

Brutal Mustang
02-12-2014, 11:45 PM
Titanium would be perfect. It's as light as aluminum, strong as steel, and doesn't corrode. However, it wasn't 'truly' discovered until 1791. Also, as a previous metal worker, I can attest that it's a real b*tch to work with.

King Neptune
02-13-2014, 12:12 AM
The coffin is buried in a forest close to a marsh, and the sea.

I think that your best bet would be gold foil over wood. If you don't want that, then you'll have to go with bronze.

ULTRAGOTHA
02-13-2014, 01:13 AM
Another idea might be an oak coffin in a bog. That would preserve for ages just fine. Cheeses placed in bogs are edible hundreds of years later.

If your monster has to be in metal, you could use a lead lining.

If it doesn't have to be in anything you could just put it in the bog nekkid. The bog dissolving bone is something you'd need to deal with if the monster is in a coffin anyway. Unlikely to keep bog water out of a coffin for 300 years no matter how you seal it.

Telergic
02-13-2014, 01:55 AM
Titanium would be perfect. It's as light as aluminum, strong as steel, and doesn't corrode. However, it wasn't 'truly' discovered until 1791. Also, as a previous metal worker, I can attest that it's a real b*tch to work with.

Did you use forged or cast titanium or sintered powders? I read somewhere that the latter is what is used for most cheap applications because as you say it's supposed to be such an incredible pain to work with.

King Neptune
02-13-2014, 02:37 AM
Another idea might be an oak coffin in a bog. That would preserve for ages just fine. Cheeses placed in bogs are edible hundreds of years later.

Are the cheeses good or just survivable? Bog aged cheeses could be a marketting gimmick.

ULTRAGOTHA
02-13-2014, 06:52 AM
They're edible but I don't know how yummy they were.

Norway has been experimenting with peat water as a preservative for fish, amongst other things.

Realspiritik
02-13-2014, 05:29 PM
Apparently peat bogs are so good at preserving certain foods that corpses pulled out of the peat bogs often have a last meal still undigested in their stomachs.

King Neptune
02-13-2014, 05:47 PM
They're edible but I don't know how yummy they were.

Norway has been experimenting with peat water as a preservative for fish, amongst other things.

That probably would add some flavor. It will be something to try.

Bufty
02-13-2014, 06:38 PM
Is this a fantasy story?

The metal, whatever it is, should be known to the folks in the story otherwise there's little point in identifying it.


I'm writing a story where an undead monster has hibernated in a metal coffin for three hundred years. I need to decide what it's made of. What metal can stay buried in the ground for so long without significant damage, and is also light enough that a small group of people can carry it?

Note, the setting is pre-industrial.

Brutal Mustang
02-18-2014, 10:49 PM
Did you use forged or cast titanium or sintered powders? I read somewhere that the latter is what is used for most cheap applications because as you say it's supposed to be such an incredible pain to work with.

Forged. :tongue

I'd almost say, sheets of it, with a steel frame, would be good for a coffin.

ECathers
02-19-2014, 12:57 AM
One plus side with a thin lead lining (or coating) is that it is traditionally used to contain demonic entities. It also has a low melting point and thus is relatively easy to work.

If you don't want to line/coat the entire coffin with lead you can always use lead on the joints and to seal it shut, and make the rest of the coffin of some other material. You could also band it with strips of lead.

Gold is aligned with solar energy, so gold foil might be particularly useful in dealing with a vampire.

If cypress was available to the coffin maker, that's another possible choice. Cypress is aligned with death energy, and might be chosen for that reason, as well as proximity to the marsh.

http://www.wood-database.com/lumber-identification/softwoods/cypress/
Rot Resistance: (http://www.wood-database.com/wood-articles/wood-durability/) Old-growth Cypress is rated as being durable to very durable in regards to decay resistance, while wood from younger trees is only rated as moderately durable.

Having never had to contain a vamp IRL (YET) I'd still postulate a combination of cypress/lead/gold.

And lots of charms, talismans and sigils too!
Figure than anyone who manages to contain a vampire probably has at least a good bit of esoteric/arcane knowledge and skill.

Not to mention a written warning to the effect of, "Numbskull: If you're reading this, DO NOT open the coffin." (Which would probably end up being in a language that the finder couldn't translate until too late.)

ETA just re-read and saw that you said "undead" not "vampire." If the undead is of some other sort, then letting us know what type it is, may lead to someone having knowledge that can add to this. Not all undead are created equal. :) Of course lead & gold should work for most of them, I'd think.

blacbird
02-20-2014, 07:51 AM
Elemental metals known in antiquity (more than 300 years ago):

Iron
Copper
Silver
Gold
Lead
Tin
Zinc
Mercury

Alloys:
Bronze
Brass

None of these fits your criteria very well. The most obvious choice would be aluminum, but, despite its great abundance in minerals in the crust of the Earth, it wasn't isolated as an element until about 200 years ago, and only became industrially useful in the early 20th century. This, on account of the difficulty in smelting it.

Titanium has a similar history, and, even though fairly common, remains expensive and difficult to produce in purity.

caw