Metallurgy and how fast things rust

  1. Martin Gill

    Martin Gill Well-Known Member

    Joined:
    Oct 17, 2015
    Messages:
    347
    Anyone know much science behind how quickly iron or steel rusts if it's cared for?

    I'm spinning on a new story set in "Viking" times - more specifically Jorvik under Danish rule - so 890AD ish. How plausible would it be that a well cared for, unused, wrapped in oilcloth and kept safe Roman sword would still be usable? The Romans left in 410AD. My assumption based on limited knowledge is this is realistic as steel is only going to rust if exposed to moisture and air. Its happening anyway for the story, but I just want to know how much liberties I'm taking with inorganic chemistry :)
     
  2. Venusian Broon

    Venusian Broon Defending the SF genre with terminal intensity

    Joined:
    Dec 7, 2011
    Messages:
    3,295
    Location:
    Edinburgh
    Just google 'oldest known iron swords' I think you'll find plenty with a good 1000 years on the clock, some way longer :D

    And just digging about there are Halstatt iron swords that are still in one piece from about 800 BCE, so that's almost 3000 years old.

    So to answer your questions, I don't see why you can't have a nice Roman sword, if well-kept and cared for. Iron is much easier to mend than bronze too.
     
    Martin Gill likes this.
  3. Biskit

    Biskit Cat whisperer

    Joined:
    Nov 23, 2011
    Messages:
    497
    Location:
    Sitting in the sun (between the rain storms)
    As @Venusian Broon says, there are swords that have survived thousands of years, but it depends on the conditions. The first thing I would worry about is your oilcloth - what is it made of? At that period, I would assume animal fats are involved, which go rancid over time, producing organic acids which might promote corrosion of the metal.
     
  4. Cathbad

    Cathbad Level 30 Geek Master

    Joined:
    Dec 9, 2015
    Messages:
    7,276
    Location:
    Everywhere.
    Having lived most my life on a ranch, I can testify that the speed in which something rusts is in direct proportion to the need of that item!

    :p
     
  5. Martin Gill

    Martin Gill Well-Known Member

    Joined:
    Oct 17, 2015
    Messages:
    347
    The concept is its a venerated item handed down for one generation to the next - not something found in a bog. So it could be oiled, repackaged etc every few years.
     
  6. dannymcg

    dannymcg I am not a robot

    Joined:
    Sep 9, 2016
    Messages:
    1,795
    Location:
    Cumbria UK
    Faint memories again, I recall hearing somewhere how scythes were left out over winter instead of being cleaned and oiled and stored in a barn. They were left blade up in the forks of trees and this helped to keep a cutting edge. Maybe a bit of old country lore :)
     
  7. Theophania Elliott

    Theophania Elliott Well-Known Member

    Joined:
    Nov 7, 2016
    Messages:
    140
    Location:
    Birmingham, UK
    I used to do historical re-enactment. We had one wet event (without decent cover) when we could watch the armour going rusty over the course of the day.

    It was miserable.

    The cleaning up afterwards was worse.
     
  8. farntfar

    farntfar Ah well.Back to normal

    Joined:
    Oct 26, 2013
    Messages:
    1,809
    Location:
    France.
    So can't you use a semi-magic oil instead of linseed oil. By magic I just mean one that isn't available at the local hardware store.

    The sword was perfectly preserved, having been wrapped in sackcloth soaked in Corbomite solution these past 900 years.
     
  9. Brian G Turner

    Brian G Turner He's a very naughty boy! Staff Member

    Joined:
    Nov 23, 2002
    Messages:
    20,142
    Location:
    Highlands
    Scabbards were often lined with wool because the natural oils in it helped keep the blade oiled and protected against water. I figure a well-cared for sword could last very well - there are plenty of centuries-old swords at the Royal Armouries in Leeds precisely because they were cared for.
     
  10. tinkerdan

    tinkerdan candycane shrimp

    Joined:
    Dec 10, 2012
    Messages:
    3,311
    Location:
    They can't find me.
  11. Martin Gill

    Martin Gill Well-Known Member

    Joined:
    Oct 17, 2015
    Messages:
    347
    I may be going 100% historical on this one.

    That was kind of my benchmark as well :)

    So I think I'm hearing that even if this was a straight up historical setting the concept of a 500 year old, well maintained, venerated as holy and protected by a cult, kept out of the rain, sword still being usable wouldn't jar your sense of realism.
     
  12. Venusian Broon

    Venusian Broon Defending the SF genre with terminal intensity

    Joined:
    Dec 7, 2011
    Messages:
    3,295
    Location:
    Edinburgh
    I think you can get away with it. :D

    Oddly though I was perusing Youtube and found a video where Lindybeige stated that many of the 'original' iron weapons that are very ancient (say the Hallstatt one's I mentioned) and displayed in museums are actually all totally iron oxide now (i.e. solid rust!) but still in the shape of the weapon and now coated in protective material.:whistle:

    However 500 years I think is probably okay. If you wanted to safe-guard it, you could hint that it was an 'unusual steel' - for example modern stainless steels do not corrode readily. Hence why could you not argue that some ancient Roman blacksmith had, by accident stumbled across a way of making such a material?

    Some Roman craftsman allegedly had invented the wonder of flexible glass (something we don't have now apparently) and then was killed by the Emperor because it might devalue the value of gold and silver. Why not stainless steel?
     
  13. Mirannan

    Mirannan Well-Known Member

    Joined:
    Jan 20, 2013
    Messages:
    1,689
    I don't know whether this is of any use to this story - probably not - but an obscure EE Smith story has the main character being instructed by some highly advanced alien how to make modern steel. "Add this green rock and that black one to the iron ore while you're smelting your iron" - and thus you have chrome/molybdenum steel. I suppose random tinkering could produce the same result.
     
  14. Kerrybuchanan

    Kerrybuchanan Delusions of Grammar

    Joined:
    Aug 3, 2014
    Messages:
    2,127
    Location:
    Ballynahinch, County Down
    I have a time-travelling blacksmith in one of my stories. He brings modern techniques to the fifth century, and makes a sword that later becomes the stuff of legend.

    Not that this is of any relevance to the OP....
     
    dannymcg and Martin Gill like this.
  15. dannymcg

    dannymcg I am not a robot

    Joined:
    Sep 9, 2016
    Messages:
    1,795
    Location:
    Cumbria UK
    Would that work? Were the materials back then robust enough? I would imagine a modern smith would just order more decent iron from internet whereas back in 'days of yore' it would be a shoddy lump of pig iron that would need considerable working to get to standard.
    Like giving a modern cabinet maker a rough hewn log to work with :)
     
  16. Brian G Turner

    Brian G Turner He's a very naughty boy! Staff Member

    Joined:
    Nov 23, 2002
    Messages:
    20,142
    Location:
    Highlands
    The Vikings actually had access to some seriously advanced steel, thanks to the composition of the ore that was sometimes used - see this thread: Ulfberht swords
     
  17. Kerrybuchanan

    Kerrybuchanan Delusions of Grammar

    Joined:
    Aug 3, 2014
    Messages:
    2,127
    Location:
    Ballynahinch, County Down
    You're quite right, but modern was a relative term in his case. He is from the first half of the 20th century (WW2), so no internet. Also a time of shortage. He was a Japanese POW who learned to survive using his wits.
     
Loading...

Share This Page

Loading...