Originally Posted by ShelledPants
WD40 is not a lubricant to be used with airsoft guns, it is a water displacement liquid (thus the WD in WD40), it is too low a viscosity to replace the higher viscosity of proper silicone oil . You would have to constantly relube the gun as the WD40 will blow off quicker than silicone oil. /thread.
Actually I've experimented with that, and I find it consistent with their technical description. It itself is a lubricant, which seems fairly light when you spray it, because it is diluted with a light solvent. That's what makes WD-40 highly viscous and good for seeping into threads. Once the solvent evaporates, the lubricant remains, and feels about the same as the mineral oil I use for rod bearings and maintaining blades on gouging machines. The stuff left over doesn't evaporate.
I still use silicone oil and lithium grease in my gearboxes, I'm just trying to see if there are any verifiable negative effects of using WD40.