That depends on various factors like what equipment we are talking about, what the ‘contact cleaner’ is and where you are spraying it!

If you have access to quality commercial products, know how to use them, and are sure they are appropriate for the use-case, 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 safe to spray on sensitive electronic equipment, then STOP, put the can down and slowly back away from the equipment!

Context

The contact cleaners and treatments I use are commercial/laboratory-grade products, some of them applied in a multi-stage process and some used as part of a custom regimen I’ve designed, specifically for use on older electronics where no such service procedures existed.

These products are very different from those often found in hobbyist electronics stores that leave oily residues and only offer short-term relief. My procedures are so effective that many of my competitors want to know exactly what I do and visit regularly, hoping to find tips. I generally don’t give this proprietary information away, but I will of course apply these processes to your equipment when booked in for service.

WD-40

WD-40 and CRC 5.56 are aerosol-delivered, low-viscosity, penetrating lubricants, water dispersers 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.

Misinformation

Some of the most problematic equipment I come across has been doused in products that are not contact cleaners like WD-40, so it’s important to understand what a contact cleaner is, its purpose, and how and where to use it. WD-40 is not a contact cleaner, nor is it marketed as one, but I’ve had people tell me that WD-40 is a contact cleaner because they read it in a forum.

Forums are generally not great places for learning being typically filled with opinions, misinformation and pseudo-science. When you need factual information, opinions are about as useful as a box of hair.

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

That’s great and maybe it was, but that doesn’t make it a contact cleaner. Don’t believe me? No problem, readers are welcome to spray it all over themselves and their hi-fi equipment, but please: don’t bring it to me afterwards!