¿Reacciona el WD-40 con la grasa?

That is completely spot on!

The original WD-40 Multi-Use Product was actually designed primarily as a water dispersant (that's what "WD" stands for) and a penetrant to loosen rusted parts, rather than a long-term lubricant.

Because it's a very light, solvent-based formula, here is what happens when you use it:

• Short-term lubrication: It will temporarily free up stuck mechanisms, but because it's so thin, it evaporates or runs off quickly.

• Degreasing effect: As you mentioned, it can act like a solvent, dissolving and washing away thicker, existing greases that are actually meant to keep parts moving smoothly (like on bike chains or hinges).

• Dust and dirt magnet: Over time, any residue left behind can actually attract dust and grime, which can gum up moving parts.

For long-lasting lubrication, it's always best to switch to a product designed specifically for the job, such as white lithium grease, silicone spray, or specialized machine oil, depending on what you're working on!

Is there a specific squeaky hinge or sticky mechanism you're trying to fix right now?