WD-40: Not Quite the Pope's Pee

This is the second time that Todd K7TFC has sent in a comment that is so good that it gets elevated to the main blog page.  When I was typing yesterday's post about how WD-40 had restored life to the hard drive in my old Tandy 1000 computer, I knew that this would stir up anti-WD-40 sentiments.  I'm grateful that Todd weighed in with such a thoughtful response.  

What can I say?  I was young and foolish.  I thought WD-40 was the answer.  Now I know better.  I have can of DeOxit D5 on my shelf.  I only use the WD-40 on my bicycle.

Todd K7TFCApril 9, 2022 at 7:49 PM wrote: 

I think even the Pope would argue his pee has already served its only real purpose: to remove unwanted substances from the body. WD-40 is useful for that purpose as well--it's pretty good at dissolving and blasting away dirt and grease from tools, hardware, or small mechanisms. That's no doubt why it worked to get your hard-drive spinning again. As a lubricant, though, it is deeply flawed.

If you have nothing else at hand, it can also substitute as an penetrating rust buster. The purpose its developers intended is coded in the name itself: "WD" stands for water displacement, and its very good at doing that. It's not so good at many of the other uses to which it's commonly put.

A very-long time ago, I worked at a company that made its own PCBs, and they had some very-precise NC machinery (programmed with punched tape in those days) for drilling and routing the boards. After a series of baffling and costly shutdowns, the culprit was discovered and WD-40 was banned entirely from the plant. The plant-maintenance guy and janitors couldn't even have any.

It was found that once completely dry, the oils and waxes in it would slowly polymerize (as they were intended), leaving behind a sticky film that protected from moisture and rust just fine, but it gummed up precision machinery. The Chief Production engineer (my father) got the company brass to ban WD-40 entirely.

Why ban it from even plant-maintenance and janitorial work? Because you couldn't keep the PCB-production crew from resorting to it in a "crisis" if they could find any at all in the building. It meant they weren't careful enough to keep the proper lubricants in stock. You could either fire them for their shade-tree-mechanic mentality, or you could ban WD-40.

Needless to say, I've kept my congenital anti-WD-40 animus alive all these years, but I do have a can I use for cleaning and water-displacement purposes. When tempted to use it otherwise, though, the memory of my father sniffing the air suspiciously for its distinctive odor flashes in my head, and I reach for something else. --73, K7TFC