Corrosion

[GAZZA]

Glorantha is basically a bronze age culture; however, I've noted a few references in some publications to adventurers exploring "ancient ruins" (sure, it's a cliche, but for a reason) with armouries containing weapons or armour that have "rusted to uselessness".

Here's the thing - bronze is fairly corrosion resistant; like most non-ferrous metals, copper oxide acts as a protective coating against further corrosion. It's not completely immune, but in the real world you find a lot more bronze artefacts have survived the ages intact than iron artefacts, and recall that the Bronze Age came first.

So my question is - is Gloranthan bronze "rustable", or is this a (minor!) oversight?

[Joerg]

2 hours ago, GAZZA said:

Glorantha is basically a bronze age culture; however, I've noted a few references in some publications to adventurers exploring "ancient ruins" (sure, it's a cliche, but for a reason) with armouries containing weapons or armour that have "rusted to uselessness".

Here's the thing - bronze is fairly corrosion resistant; like most non-ferrous metals, copper oxide acts as a protective coating against further corrosion. It's not completely immune, but in the real world you find a lot more bronze artefacts have survived the ages intact than iron artefacts, and recall that the Bronze Age came first.

So my question is - is Gloranthan bronze "rustable", or is this a (minor!) oversight?

The patina on bronze is a carbonate/hydroxide in the real world, which means that it can be whittled away by even slightly acid humidity. If you have  perfectly dry barrow, bronze objects are going to last quite a long time, but when you dig out remnants of bronze or copper items, you find them through the halo of greenish or blueish corrosion permeating the soil around them unless there is active rot there which will turn the dissolved copper black (sulphides).

It is true that iron artefacts are way more prone to rusting away than bronze artefacts. But then, in our world, the oldest copper artefacts are about 10,000 years old, the oldest bronze artefacts about 5,000 years. If you believe Dara Happan calendars, Umath was dismembered about 42,000 years ago. Early Vingkotling artefacts are from about 8,000 years ago. Nochet claims continuity from way before the Lesser Darkness (12,000 years ago). Brass (alloyed bronze from molten bones) would have been available for more than 100,000 years (Lodril's wrestling match), according to the Dara Happans.

The bronze items that have been found in digs aren't usually in usable shape - they require painstaking reconstruction to be made look good again, and if you want to do any experiments on strength or durability, you create replicas (the best you can) and test those. I can't think of a single occurrance of grave robbers picking up a bronze weapon from a find to disembowel their unlucky helpers to keep the preciousssss all to their own.

Rusted to uselessness doesn't mean that they couldn't be restored, at the very least for ceremonial use (creating a magical link to the original owner and their prowess and possibly magical powers used with these). And however brittle they may be in the mundane world, bringing an authentic weapon to the Other Side may gift you with the weapon at its prime if you enter the right period in the Gods War. And the heroquest reward might be that the weapon retains those properties as you return.

Edited June 13, 2020 by Joerg
Disclaimer: I am a chemist, not an Archaeologist by trade.

[Shiningbrow]

I suppose that should lead to a fairly obvious question.... Do enchanted items corrode?

[Joerg]

14 minutes ago, Shiningbrow said:

I suppose that should lead to a fairly obvious question.... Do enchanted items corrode?

My reply would be "yes, but a lot slower". Enchant Metal strengthens the "metal" quality and should make a decay of that harder. This doesn't make them immune from stuff like gorp corrosive liquid (acid only in the sense of "sharp corrosive", not in any Brønstedt or Lewis sense), but gives them more points to wear off, too. Likewise, hammered (as opposed to melted and re-cast) godsbone should retain some of the divine quality of that piece, making it harder to corrode, too. But then, mythic considerations come in here, too. If the corroding force caused the dismembering or death of the previous owner of this bone, it may be just as effective, or even more so.

[GAZZA]

Good stuff @Joerg, I clearly came to the right place to ask.

[soltakss]

6 minutes ago, Joerg said:

27 minutes ago, Shiningbrow said:

I suppose that should lead to a fairly obvious question.... Do enchanted items corrode?

My reply would be "yes, but a lot slower".

Also, people take care of their magic items, cleaning, polishing and oiling them, which protects against corrosion.

Personally, I don't bother with that kind of thing in my games. I just assume that Adventurers take care of their equipment to prevent things like corrosion.

Items found in ruins may or may not be corroded, entirely at the GM's whim, in my games.

[Joerg]

14 minutes ago, soltakss said:

Also, people take care of their magic items, cleaning, polishing and oiling them, which protects against corrosion.

Personally, I don't bother with that kind of thing in my games. I just assume that Adventurers take care of their equipment to prevent things like corrosion.

Unless it is technology beyond their ken (like giving metal to mesolithic hunters or neolithic farmers), I'd agree on that under normal circumstances. When faced with unfamiliar circumstances (like first exposure to salty sea spray), I might give them a little grief - not enough to de-value the item, but enough to make them spend some effort or resource.

I certainly don't game out letting an item in soil corrode away... not any more than having an Eirithan watch the grass grow in a pasture she may have blessed for an extended stay of her herd.

Quote

Items found in ruins may or may not be corroded, entirely at the GM's whim, in my games.

Exactly. My comments were directed at giving the GM arguments against detail-obsessed wise-ass players like yours truly.

 

For other ideas, I refer you to Andrew Eldridge's subcult of Chalana Arroy.

Edited June 13, 2020 by Joerg

[Austin]

FWIW I'm not convinced Iron rusts in Glorantha. I suspect Bronze corrodes because a) how common it is, which means b) lots of Air/Storm gods died in the Gods War, so there's plenty of mythic reason for bronze to "fail." I'm not convinced that a similar story currently exists to explain what we terrestrially understand as the oxidization process.

NB: it's become something of a joke in my game group that metals are completely, utterly bizarre in Glorantha because there's no chemistry, just mythology, and that colors a lot of my speculation regarding them.