Keyboards and dishwashers

Click picture above for full gallery.

Now, this is certainly nothing new, as multiple sources have already reported that some keyboards are dishwasher-safe, or that they can at least take one round of dishwashing:


What piqued my curiousity was that some comments reported problems, a few total failures, and all very varying drying times and techniques, like shaking the keyboards every 1-2 days for a full week. Sunlight was often mentioned as a quick way to dry the keyboards.

Why did I choose to delve into this? In Finland, keyboards are categorized as electronic waste (“SER-jäte”) meaning that they contain hazardous materials. Granted, most of the chassis is plastic, but the circuit board and the connector sheets require special care after disposing.

Now, a single keyboard might not seem like much of a problem, and certainly not like much of an investment, but multiply that by a each computer we have at the Computer Science Department and you will get multiple cubic metres of wasted materials. What’s worse, often these keyboards get thrown not because they are faulty but because it would cost too much to clean them!


A particularly gruesome case. The picture doesn’t do it full justice.

What if there was a way to get the keyboards clean in an automated fashion, requiring nothing but a dishwasher and some spare time to wait for drying? A long story short, I assembled six keyboards and an optical mouse to figure out what exactly happens to these devices during the normal dish washing cycle. I got the following devices as test subjects:

  1. Dell RT7D60 USB with electronic card reader
  2. Keytronic E06102SV019-C PS/2
  3. Logitech Y-ST39 PS/2
  4. Logitech Y-ST39 PS/2
  5. Logitech Y-SG13 PS/2
  6. Logitech-branded Liteon-HIS Y-UT76
  7. Logitech M-BT58 Optical USB Cord Mouse

I washed them in a max. 50 C washing program for glassware, and deselected drying. After the program finished, the keyboards were positively drenched, and had to be drained before removal from the dishwasher. I left the keyboards to dry over the weekend for over 86 hours.

On the following Monday, units #1, #3, #4, and #7 worked perfectly without additional complications. It was specially encouraging to notice that the mouse belonged to this category, since during prolonged use, mice tend to become almost as grimy as keyboards.

The other three worked very poorly or mostly not at all. I opened the keyboards and noticed that most of the devices had accumulated water between the connector sheets used to signal key presses. Interestingly, even the working units exhibited water droplets, but still worked perfectly! This leads me to believe that there exists a low-cost technique which allows all keyboards to remain dishwasher-safe.


Pens and pencils inserted between sheets for additional air circulation

For the nonworking units, additional maneuvering was necessary to gently peel the sheets apart and leave them to dry for an additional 24 hours. I’m quite sure that all units would’ve dried a lot faster if they were opened to begin with, but the point of the exercise was to get the keyboards clean with minimal user intervention.

Finally, after the remaining three keyboards had dried out completely, I reassembled them (with one flaw) and retried the testing procedure. Now, all six units plus the mouse were working perfectly. We had now removed a number of keyboards from the waste pile and put them back into active use.

Additional things to research:

  • Effect of microbes and other growths before and after dishwashing
  • Medical recommendations for cleaning keyboards, specially in multiple-user environments like the department
  • How many times a keyboard can be put through the washing cycle
  • What is the minimum change necessary to allow for fully automatic washing, i.e., no chassis opening required
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