I have a possible need to coat hardware parts in a rigging application to reduce visibility. This installation is indoors, in a semi-climate-controlled enclosed space (a church; no worries about rain, but the temperature will fluctuate between 60 and 85*F as the HVAC is told to maintain more or less strict temperature ranges for Sunday services and other functions versus "downtime" during the week). It's overhead rigging; once it's in place and painted/coated, it won't be touched for years, so I'm not worried about physical durability of the coating against abrasion. There are a couple different alloys involved, but it's pretty much all steel; the cable is galvanized 7x7 aircraft cable (yes I can buy it pre-coated but I would prefer not to), the clips and thimbles are zinc alloy stainless, and most other pieces (eyebolts, turnbuckles) are Grade 5 medium carbon steel.
So, do I go eco-friendly with a zero-VOC satin latex just to camouflage the parts, or do I still need an oil paint to ensure that the coating won't fail due to the temperature swings?