Should I spray contact cleaner into my equipment?

That very much depends on what the ‘contact cleaner’ is and where you are spraying it!

If you have access to quality commercial products and you know how to use them, go for it. But if you don’t know what/how much/how/where/why or if you think that WD-40 and CRC 5.56 are contact cleaners and OK to spray on sensitive electronic equipment, then please: put the can down and back away from the equipment, preferably with your hands up!

The contact cleaners and treatments I use are commercial, laboratory-grade chemicals, some of them applied in two or more stages and used in a specific regimen. These are quite different to the low-quality products often found in hobbyist electronics stores that leave oily residues and yet are loved by some because they’re cheap and all they know.

Do you want to know what to use and how? You’ll need to successfully service expensive laboratory test and measurement equipment, by the book, as I do. You’ll also need to devise and test some of your own procedures as I have over many years of doing this work.


Some of the most problematic equipment I come across has been doused in products that are not contact cleaners, like WD-40. One piece I remember was soaked in it and the owner wondered why I didn’t want to work on it!

WD 40.2
Note the uses listed by the manufacturer. You won’t see contact cleaning.

WD-40 and CRC 5.56 are aerosol-delivered, low-viscosity, penetrating lubricants and corrosion inhibitors. They consist of light oils suspended in volatile carriers that evaporate, leaving oily residues that protect metallic surfaces. These residues attract dust and dirt, less important on nuts and bolts perhaps, but a very significant problem in sensitive switches, relays and potentiometers with human hair thin gold wipers, for example.

In these delicate structures, dusty, oily residues trap dirt, increasing friction and turning it into a kind of abrasive paste, making them dirtier and less reliable over time. The use of pressurised aerosols containing oleophilic solvents can also flush out greases and oils that are part of the smooth mechanical operation of the switch/pot/etc.

At some point, deep cleaning and re-lubrication will be needed to restore proper functionality, as long as permanent damage has not been caused. This follow-up work is time-consuming and technical, and sometimes too late. Didn’t know any of this..? You’re welcome!


It’s important to understand what a contact cleaner is, its purpose, and how and where to use it. Failure to learn this will undoubtedly lead to WD-40 use which will make things worse in the long run. WD-40 is not a contact cleaner, nor is it marketed as one.

I’ve had people tell me that WD-40 is a contact cleaner because they read it in a forum. People who know me will know how my eyes glaze over about such comments. Forums are often not great places for learning and most folks contributing to public forums are sharing opinions only. When you need facts, opinions are about as useful as a box of hair and just one reason I offer our advisory service.

But Mike, WD-40 was developed for NASA, for use on rockets!

Someone, somewhere

That’s great and maybe it was, but again that doesn’t make it a contact cleaner or treatment. Don’t believe me? No problem, spray it all over you and your hi-fi equipment, just don’t bring it to me afterwards!

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