Rust on models and war machines look great, it adds texture and depth to your paintjob and just overall makes any model look really good, BUT, these are dwarfs, they take pride in their craft, they maintain their machines so a very rusty skullcracker would look amazing but feel very out of place.
What do you guys think?
I completely agree, people nowadays just paints rust on about every metal piece without even taking into consideration the lore behind it.
As you well stated, races that take pride in their craft would never allow their machines to go rusty. Rusty skaven or goblin weapons? It would be strange if they were NOT rusty. Rusty dwarven war machinery? No way in hell.
Its like seeing space marines with rusty armor like, cmon, they have people devoted to maintaining the armor and youre telling me its gone rusty…?
Dwarfs, no. Chaos Dwarfs with emphasis on chaos… I think dirt and grime fit into a grimdark approach.
Also, the amount of metal in the chaos dwarfs/ smiths empire must be immense. That’s a lot of hobgoblins to hire to polish it all.
“Hogboblins to hire”
Haha, I don’t think anyone was hired, or paid! 
I think a little bit for character is not bad, especially if it is verdigris on copper-based metals (brass/bronze etc.) rather than strict iron oxidation but too much and it falls away from theme. Chaos Dwarfs do live in what would seem to be a fairly caustic environment so a little rust doesn’t feel terribly out of place.
As for hobgoblin units or greenskin units it makes more sense since they aren’t going to hold themselves to the same standards
I’m too torn on this issue, now that I’ve almost finished printing a huge amount of war machine and I’m about to start painting; a good amount of rust/dirt/oxide would greatly speed up the painting process, giving the army an interesting grimdark look that fits well with its chaotic soul.
On the other hand, they’re Dwarfs for god sake! Even if corrupted by evil forces of Chaos I don’t know if I could accept a dirty look.
I think that I’ll just decide on the gut feeling with the brush in my hand.
You can still give them an oily, grimy look without using rust I suppose. Gotta keep the machine’s greased.
Has anyone seen any truly grimdark CD?
I’m talking so grimdark you need a torch to find them against a black background 
I almost imagine Daemon energy being like super radioactive and corrosive at the same time. Because it’s the raw essence of chaos, and ultimately would want to escape.
So things like burning all your clothes at the temple to Hashut after having been on a long campaign would make sense, with that special Daemon axe you made dissolving into useless junk within a year after the campaign etc.
I like it in context, I do like to think (probably too much) of the fluff and lore behind something rather than just throwing colours at it. Not that there’s anything wrong with that either.
As you may tell by the title of my Blog I did lean into heavy rust effects for mine for a few reasons. Firstly being I went for bone armour and I didn’t want them to look clean as it would be too bright, secondly then because the fluff I came up with for mine was along the lines of a hive mind/Necromancer so the High Sorcerer on Taurus would have been the cleaner model standing out against everyone else and my warriors etc were all just waking suits of armour, zombies almost, no care taken in cleaning armour for sure. The Bull Centaurs next to them then had more temp natural weathering rather than weathering over time like the warriors.
So I think it can look good when followed by some theory or fluff behind it. For me that is. Rust for rust sake not always good.
So for example here, rusty warrior/captain as he is from the ranks, Sorcerer a bit cleaner
Has anyone seen any truly grimdark CD?
I’m talking so grimdark you need a torch to find them against a black background
Do you mean like this? Only mars black and a dark ink wash 
Surprisingly you don’t see it more often given the “black shard” armour. As for rust and patina, its more likely then not dependent on time and availability. Difficult to scrub or clean while on campaign, or dealing with a siege, and it only takes a few minutes to have something rust with enough acid.
