Thread: What's wrong with WD40?

I see people here warning against using it to protect straights after use. It's cheap, available, convenient. Why shouldn't I use it?

As long as you are willing to spray it directly on your face, then there is nothing wrong with using it on your razors. If you are concerned that it might have some level of toxicity risk, then you might want to use something else.

Originally Posted by pcb01

I see people here warning against using it to protect straights after use. It's cheap, available, convenient. Why shouldn't I use it?

WD40 is not meant for the skin so it's not a wise idea to use it on something that will go on the skin. Also WD40 gets nasty and sticky after a time so it wouldn't be the best for storage as it would be a real pain to remove.

I have used it for "oiling" the pivot area. No probs there.

WD40 is mostly solvent. If you need a penetrating solvent that leaves behind a tiny amount of lubricant behind once it has evaporated, then WD40 is great.

Example of misuse: Trains in the UK used to have "slam doors". The door catches needed to be kept greased. But sometimes they used a WD40-like oil instead. The solvent dissolved the grease, which washed away. The door catches stopped operating smoothly and a few passengers were killed falling out of trains.

Use the right tool for the job.

WD40 is intended to be used to loosen rusted bolts. It contains mostly solvent and a bit of some sort of oil; the solvent helps the oil penetrate deeply into the rust. It is not designed to be used as a surface treatment for clean steel. The solvent will wash away any existing oil, and the oily substance left behind by WD40 is hydroscopic which will quickly rust your razor.

Originally Posted by mparker762

WD40 is intended to be used to loosen rusted bolts. It contains mostly solvent and a bit of some sort of oil; the solvent helps the oil penetrate deeply into the rust. It is not designed to be used as a surface treatment for clean steel. The solvent will wash away any existing oil, and the oily substance left behind by WD40 is hydroscopic which will quickly rust your razor.

I would say it makes sense that WD40 can dissolve grease, but I do not agree that WD40 is hygroscopic. That makes no sense. First, I don't know of many oily substances that are hygroscopic. Second, the name of WD40 is from the chemist who was trying to derive a water displacing anti-corrosive. The name is an acronym for Water Displacement attempt number 40. If WD40 caused rust, I doubt if it would be as commonly used as it is.

Originally Posted by Utopian

I would say it makes sense that WD40 can dissolve grease, but I do not agree that WD40 is hygroscopic. That makes no sense. First, I don't know of many oily substances that are hygroscopic. Second, the name of WD40 is from the chemist who was trying to derive a water displacing anti-corrosive. The name is an acronym for Water Displacement attempt number 40. If WD40 caused rust, I doubt if it would be as commonly used as it is.

Most of us in my business wont touch the stuff as it seems to create additional problems. While it does loosen problematic nuts and bolts and free up hinges and moving parts those benefits tend to be short lived and in short order these parts begin to stick real bad and I have also noticed a serious tendency towards rust on the stuff I had used it on before I knew better.

Not good for the scales, period....

Yup, I'm definitely wrong there.

There are better things to put on your razor and your face than WD40.