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Comment by davekiss | Hacker News Reader

I learned a lot about WD-40 from this project! This is a highly debated topic, but their website leans into the fact that WD-40 is, indeed, a lubricant.

> While the “W-D” in WD-40 stands for Water Displacement, WD-40 Multi-Use Product is a unique, special blend of lubricants. The product’s formulation also contains anti-corrosion agents and ingredients for penetration, water displacement and soil removal.

Regardless of the facts, when all was said and done, they were the ones judging the entries, sooo… yep, it's a lubricant.

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It is a lubricant, just not a very good one for most uses. It can't bear much load and it tends to just dissappear in a short time.

I once replaced a series of mortice lever locks in a first house that were very worn after a decade of use. You had to shake the key to get them to open. I was amazed on opening them to find them completely dry, when they come greased. I suggested they lubricate the replacements occasionally. They replied that they sprayed them regularly with wd40. This has washed the grease out and left... virtually nothing.

For what it's worth, old lock grease tends to move away from where it's needed and turn into a hard, waxy substance. It's arguably better to have a lock cleaned and slightly lubricated with WD-40 than one gummed up with ancient grease and dirt, or worse, rusted.

I've heard a lot of anecdotes in every direction: only use graphite, only use a cleaning solvent. I've never read anything authoritative and I suspect the ideal approach is to regularly (e.g. every decade) disassemble the lock, clean it thoroughly, and inject grease, but nobody is going to do that.

I'm pretty sure with locks, you want a dry lubricant. So graphite, or better yet, a PTFE spray lubricant. Hasn't failed me yet.

I think that's one of the biggest screwups people make with WD-40 is that it's basically just a petroleum solvent and other than maybe initially unsticking things, it often makes the problem worse. As far as solvents go it's not particularly great, and in terms of lubricating or breaking free it's pretty bad. I'm surprised they still sell as much of it as they do (chalk it up to good marketing), when for basically everything there's a better choice (protip: if something is really stuck, the best tool provided you don't have dogs or children getting near is going to be acetone mixed with a good ATF).

TIL that ATF=automatic transmission fluid.

Still unclear on why this particular mix is optimal for unsticking things but Google suggests a lot of people use it.

Yes, I've used ATF to fix seized up motors. Just fill cylinder and let it sit for a few days.

Jack of all trades, master of none. It is a better lubricant than most solvants and a better solvant than most lubricants, it will always be worse than a specialized product, but if you are only allowed a single can, that's a good choice. Affordable and widely available too. Oh and the pressurized can form factor is convenient.

Hate the smell of ATF but it was a life saver on some hinges that I wanted to save, but I couldn’t get to move after trying penetrating oil, wd-40, and some other things (not in that order ). ATF after a few hours succeeded.

This was in fact one of my big learning experiences in mechanical work. As a kid, my bike was running rough so i took it apart, cleaned oout all that yucky/dirty grease from the bearings using WD-40, and then reassembled it all only to find it was even worse than before. Only a few years later did I learn that wd-40 is a terrible lubricant for bike ball bearings.

You can see a similar effect with standard skate bearings used in fidget spinners - most bearings come pre-greased with a fairly high viscosity lubricant. If you spin the spinner, it will slow down quite fast, but if you take the bearing apart, clean out all the grease, and reassemble it, it will run wicked fast and long. Until some dirt gets in, at which point, grease would have worked better.

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