> The actual ingredients are literally on the safety data sheet
This is an oversimplification, in a way that is likely not obvious to a lot of people on this (software-focused) forum. An SDS does not have to list exact amounts, does not have to disclose some details of how an ingredient or mix of ingredients was processed, and (depending on jurisdiction) may not have to identify some "safe" ingredients at all. Some ingredients may be identified in relatively vague ways, that are sufficient for safety purposes but do not reveal the exact product. As the SDS you linked to says "The specific chemical identity and exact percentages are a trade secret". An SDS is certainly very helpful to reverse-engineering a product, but it doesn't tell you everything.
All that said, yes, the main strength of WD-40 is its marketing and ubiquity, and claims about its secrecy have more to do with marketing than anything practical.
> Some ingredients may be identified in relatively vague ways, that are sufficient for safety purposes but do not reveal the exact product
Where I find this can be fun is that different countries seem to have different requirements for precision. Or just straight up different formulations for the same thing.
The SDS should include all SAFETY relevant information/ingredients for whatever jurisdiction. If the local area doesn't really care if it's hexane or pentane from a safety perspective, they'll likely just be lumped together behind a generic name/cas number.
Hopefully if you sum enough of those SDS across different jurisdictions, the actual list of ingredients will come out. Though I guess it isn't that simple.
I once had a problem with the ignition lock I couldn't turn the key, my mechanic told me that that could happen on a very hot day with that model. "use a lubricant or wait till it's colder" - "Would WD-40 do?" -"Guess so" made it worse. with the help of the AAA (well, the equivalent in my country) and an oil spray I could turn the key, since then I've always an oil spray with me
Had the same problem with my moto (key not turning the lock). Fortunately, there was a car nearby and owner had a spare jug of oil. I put some oil on the key, put it in the ignition lock, waited for 5 minutes, and it started to turn again.
Although I must admin WD-40 helped me in the past opening an old door lock.
I suspect the difference is whether (as with the old door lock) there is no lubricant at all and anything is better than nothing, or whether (as with the ignition key) there is a lubricant there which was designed for the purpose but for some other reason isn't working as intended, and which the WD-40 will displace and replace with something worse. "Fails in hot weather" sounds either like some sort of thermal expansion problem or the intended grease gets too thin to properly lubricate a high-pressure contact area. Or there just isn't enough of it.
I was 2000 km from home (1242 miles) and I was in panic because it was pretty uninhabited place. My bike is 12 years old but I used it in very harsh conditions (dirt, mountains).
Probably should replace the lock but it is so expensive.
In both cases, the real issue is when the oil (eventually all do) oxidizes and ‘gums’. Tight tolerances make it cause worse problems sooner of course, but it’s the same problem eventually.
Putting new fresh oil in it often temporarily fixes it because it dissolves some (or a lot) of the old varnish. Acetone can often do the same thing too, but can also wash the varnish deeper into the mechanism where it turns into really solid ‘plastic’ when the acetone dissolves.
This is an oversimplification, in a way that is likely not obvious to a lot of people on this (software-focused) forum. An SDS does not have to list exact amounts, does not have to disclose some details of how an ingredient or mix of ingredients was processed, and (depending on jurisdiction) may not have to identify some "safe" ingredients at all. Some ingredients may be identified in relatively vague ways, that are sufficient for safety purposes but do not reveal the exact product. As the SDS you linked to says "The specific chemical identity and exact percentages are a trade secret". An SDS is certainly very helpful to reverse-engineering a product, but it doesn't tell you everything.
All that said, yes, the main strength of WD-40 is its marketing and ubiquity, and claims about its secrecy have more to do with marketing than anything practical.