Hey Dave,
Merry Christmas back at ya! My reason for posting the link to the MSDS was to show among other things the solubility of WD-40 in water. To insinuate the <10% non-hazardous constituents are in fact water is not a very responsible thing to do for such a learned person as yourself. You could lead wayward thinkers into believing all the wives tales are true just because of some personal injustice you think you have suffered at the hands of WD-40. Did your gun rust because you put too much reliance in WD-40?
A colloidal suspension is the only way for oil and water to mix. This can happen two ways;
The first, a way we all know, is an "oil in water" suspension where the oil is surrounded by water. This happens everyday when we wash our hands with soap. The surfactants in soap break the oil into small pieces and surround it. In a microscope it looks like a tiny egg, the oil looking like the yoke. This is how our hands get clean. It is a very stable suspension and will last for quite a while depending on the type of surfanctant/s used. This is not how you might find water in WD-40.
The second is a "water in oil" suspension. This can happen for example when you take a small jug of diesel put a little water in it and shake the jug vigorously. In a clear aliphatic distillate solution the water would indeed appear as a white cloud but, as you stated it would quickly settle out because the "water in oil" suspension is not at all stable. The oil particles have an affinity for each other leaving the water all alone to precipitate out and down with gravity to the bottom of the container. You might, as I alluded earlier, find water in this manner in WD-40.
If I may, a gallon container of WD-40, as they have been sold in for years to refill the cute little spray bottle, once opened will begin to get water in it just as the gas tank of you car does. The humidity in the air.....but I digress, you being a Metrological Measurer of things must already know of what I'm speaking...sorry. My point is, the containers in your example may have already been opened and in use for some time...no?
Rather than have you attempt to make me believe they were new cans or that you are indeed not fibbing, I'll concede your point, to a point, in that the same thing (condensation of atmospheric water) may indeed happen during packaging, although extensive precautions to prevent it are most surely in place. And that the severe instability of the suspension would lead any water formed in this manner to be easily disposed of during packaging or in the highly unlikely event to be quickly expelled with the first use of the can, be it pump or CO2 driven. And also that the constituents listed are derived from crude oil at very high temperatures and pressures where water finds it extremely hard to exist I'd say your point is a small one. Almost as small as your point to my ignorance.
If you do indeed have any empirical data you'd like to share concerning water in WD-40 as packaged by the manufacturer, I, dare I say we and they, would love to see it.
People who have no knowledge in such fields are easily duped by others who put forth convincing sounding strings of words that otherwise have no merit. I'm not one of these....in this area anyway......My ignorance abounds in others though.
Best Regards,
Bob