Mechanicus Standard Grey highlighted to slightly metallic.

[General Strike]

So, I have both my Armigers painted in Mechanicus Standard Grey, because I like the matte dark grey look. My plan is to heavy drybrush with Longbeard Grey, then do light drybrush highlights (dark lights?) With Necron Compound to add metallics to the edges of the matte grey. Then I want to over it all with nuln oil. I plan to Leadbelcher and Bronze the pipes and such on Armigers, but want to keep the majority looking like a worn grey painted mechanical bits. Any suggestions for my plan?

[Kinstryfe]

If I understand correctly, you want it to look like metal parts painted grey, that are being worn to show the metal underneath? If that's it, then I'd say you're on the right track for sure. Myself, I would pretty much do what you said and then do the following:

After washing, go back with a brush and touch up some of the scratches and dings with the metallic. What you'll want is a non-uniform look of wear and tear. Hit the occasional non-edge piece too, because not all scratches would be on edges; collisions, arms fire, and other stuff would hit all sorts of areas. You may even want to carefully cut tiny scratches and divets in places to show heavier damage. Stippling can be used for areas of inconsistent damage to the paint job.

After it's thoroughly scratched up, if you went overboard you can go back with the grey and undo some of the damage. You can also make good use of multiple washes to give character to some of the damage. I've done larger metallic areas with heavy black washes on and around it for flame damage, greens to show discoloring from chemicals, violets and blues for heat discoloration, brown for oils. Pretty much play around depending on just how beat up you want the machinery to look.

[General Strike]

That's exactly what I was going for. Thank you! Any advice on doing hazard stripes? I was thinking of doing some near the exhausts and joints of the Knights insides.

[Kinstryfe]

I suck at hazard stripes :) hopefully someone who's better at them will be able to chime in.

[Danny Cyanide]

Duncan goes over hazard stripes really well in the Armiger painting video, check it out here:

 

https://youtu.be/P4Qxda7OfK0