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I have a real problem with WD40. Ever since I used it on a car hood latch. My step daughter took the car to college with her. Without my frequent additions the hood latch first froze up and then opened at 60 mph. Since then I have realized this stuff is to be used only to unstick parts and must be followed by a good lubricating oil. The problem is that the world seems to think this stuff is great. I keep seeing comments like " it works good I merely add a little every few weeks" You should not have to re lubricate something every few weeks. It should last for years! Are there any other experiences out there like mine?

wd 40 is essentially aerosol kerosene. is remove any lubrication and what is left evaporates.

your evaluation is correct. wd40 is great as a penetrant. (but PB blaster is better) but you must then use a lube.

i use white lithium grease. sold as water pump grease, or water proof grease.

My problem with wd40, is that I invented wd39, and no one remembers it. I was going to make a fortune, and those nasty wd40 folks beat me to the punch! I have 25,000 cans of wd39 rotting away in my garage.

well, at least the cans wont rust out! from the inside anyway

I used to and still do to a limited extent rebuild and performance modify fishing reels. I’ve seen enough damage on reels caused by WD40 to tell me not to use it.

WD40 dries up and leaves a residue that looks a lot like dried gasoline varnish. This residue is a pain in the arse to remove paticularly from a reel. I used to charge extra for any reel exposed to WD40 or salt water and considered both about equally destructive.


WD40 is a very handy product, but the trouble is that people think it’s a lubricant or a penetrating oil, neither of which it is. It is a really handy water displacer (hence WD), which is really good for keeping stuff that doesn’t usually require a lubricant from corroding and becoming hard to move. For example, I always give my wheel studs a coat of WD40 when I’m changing the tires over and it makes it so the lug nuts don’t rust on and become difficult to remove next season. Every handyman should have a can of it right next to the PB blaster (or similar) and the white-lithium grease and they should know when to use each.

I used to use WD-40 to clean my oil drain pans. I like the smell and it cleans up pine residue very well. I don’t use it on cars anymore.

WD-40 is not a good lubricant for metal at all. It’s decent on plastic, rubber, nylon, etc.
Aerosol white or red grease works well on hinges, latches, etc.

I seldom ever use that stuff; there’s better alternatives.

Well WD-40 is formula #40 of a Water Displacement. It is what it is. Nothing more. As you have noted it will tend to clean off sticky (like old oil) stuff and it leaves some lubricant, but that lubricant will dry out and become more of that sticky stuff.

It has a lot of uses, but you are right that many people fail to see its limits.

I can’t stand WD40. It’s liquid gum. I use PB Blast and white lithium only.

Twenty years ago I was in a car with very bad ignition wires, coming home at night during a rainstorm. The car spit-n-sputtered and would barely even go 20 mph. The ignition wires were arc’ing from the rain and moisture. We sprayed it liberally with WD40 and amazingly, it worked well enough to get us home. (The wires were replaced the next day IIRC.)

I agree with all the replies in this thread.

I don’t think it says anywhere on the can that it lubricates. At best it will loosen up some dried grease and that will flow to the affected area. It works as well as stodard solvent at lubricating things. That makes up about 40% Marvel Mystery Oil, at least that has some oil in it.

I still like WD40 for some things, but if you really need to penetrate a stuck bolt or rusty cable I’ve got the greatest stuff. A 50/50 mix of ATF and Acetone. Simply amazing for penetrating oil. Make sure you don’t get type-F fulid, though. I grab a bottle of DexIII and add it to an old windex bottle, top it off with Acetone from the hardware store, and have at it.

This probably does make a good penetrating fluid, but jeez don’t get it anywhere near paint.

Yeah, prolly should have made some cautions. The fact that the acetone will be sold as “paint stripper” in most stores means don’t use it near paint. And don’t use it near a flame. WD40 is non-flammable, acetone is extremely flammable. BUT, if you’ve got a bolt that won’t budge it works great. And once the acetone evaporates the ATF stays behind as a pretty good lubricant.

Who told you WD 40 is not flammable? It is very much flammable, similar to gasoline. The one and only good use I’ve found for it is a safer alternative to either for trying to start a sick small engine like a chain saw, weedwacker, or lawn mower. You can spray it directly in a carburator and run an engine on it.


The PB can looks like a cheap advertisement for 3D glasses from the back pages of Popular Science. But the biggest gaffe in the artwork was how they arranged the manufacturer and product name. B’Laster makes PB pentrating catalyst along with a range of other products. But everyone I know calls it PB Blaster. Seems to roll off the tongue better. Even stores selling it advertise it that way. I wonder if there are any other products that were as successful where the buying public adopted an altered use of the name? Yep, got me a brand new Cordoba Chrysler… :slight_smile:

That’s strange Skip. Just a couple days ago I was working on a stuck bolt in a Benelli motorcycle. I was alternating WD40 and a plumbing torch (the WD was handy or I’d have gone for the good stuff up the hill in my garage). If WD40 is flammable it isn’t very flamamble, cause I would hit the bolt with a good shot of it, then the torch for a while, then the WD40, then immediately the torch again. Didn’t burn for me. It might require compression to be flammable.

The propellant in the can is flammable but the product itself isn’t. You don’t want to spray it anywhere that has an open flame or spark on it, but once it’s on there, it’s not especially flammable.

WD-40 is flammable! I know a man who almost died using it to lubricate a drill bit as he drilled through a piece of metal. It caught fire, and burned on all the WD-40 soaked surfaces, including his soaked, gloved hands.