When we dispose of old computer equipment, we generally keep most of the parts that we can use elsewhere. We pull out hard drives, memory, CD-ROM drives, etc. We then use these as replacement parts in newer computers, and reduce the amount of money we have to spend on parts.

Keyboards are a problem, though. They’re generally pretty durable, and we often find that the keyboards for computers that we’re discarding are perfectly serviceable. They do have one problem, though: they’re filthy. After six or eight years of students and staff members constantly using them, they’re covered with dirt, dust, coffee stains and cracker crumbs. If you turn one over and shake it, all kinds of interesting things fall out.

They are possible to clean. Take a cotton swab and some rubbing alcohol and almost anything will come off. You can pop the keys off and clean the sides of them more easily. You can use compressed air to blow the dust out. But this is time consuming. When a new replacement keyboard is only $10, why would I spend an hour trying to clean up an old one?

A while ago, James Conley, from Piqua City Schools, suggested on the state tech coordinators’ listserv that dishwashers can be used to clean up old keyboards. In June of 2005, he wrote:

“However, for the really bad keyboards, a friend of mine suggests using a dishwasher. Don’t laugh, it works great and you can do about 20 keyboards at a time. Don’t have it dry them of course. I have used it to resolve pop being dumped on keyboards. It is the only thing that will get them working again.”

Last week, I was cleaning out a storage room and had a bunch of old keyboards, so I decided to try it out. I loaded up fifteen keyboards of various models. Seven were Gateway keyboards, two were Dells, two were Compaqs, and four were Apples. All of them were PS/2 keyboards except the Apple ones, which are USB. I carted them down to the MH unit, which has a kitchen with a dishwasher.

I set the dishwasher for a normal wash, without heated drying. I didn’t add any soap. I ran it through the cycle, and then pulled them out. I think I blew a couple fuses in MH kids’ heads when they saw me open the dishwasher and start taking out wet keyboards.

I stored them, keys-down, on paper towels for a week. Today, I tested them. For each keyboard, I rated it on functionality and cleanliness on a scale of 1-10. For the USB keyboards, I also tested the integrated USB ports on the keyboards. The numbers are probably pretty meaningless, since I didn’t bother to test the keyboards before cleaning them, and I didn’t assess their cleanliness then. But here’s what I found:

Of the 15 keyboards, 11 of them were in a condition good enough that I would deploy them. Of the remaining four, three were not clean enough, and one didn’t work. The one that didn’t work has a malfunctioning space bar. It’s possible that it was broken before the cleaning, but I don’t know for sure.

On my 1-10 scale, the median cleanliness score was 8. I consider a score of 7 or higher to be good enough to put the keyboard into use. Of the failures, interestingly, two of the three were the Compaqs.

Normal people would stop here and say “73% of the keyboards washed with the dishwasher end up in good enough condition to put to good use. Wash all of the old keyboards, throw away the ones that don’t work, and move on. You will certainly have more keyboards than you could ever use.”

I’m not “normal people.” I took one of the Compaq keyboards that scored a “5” down to the kitchen. The food service supervisor helped me run it through the dishwasher. Twice. There are a few differences between the garden-variety kitchen dishwasher and this industrial-sized one. First of all, there’s no way to not use soap. It’s automatically added. Second, it uses 160 degree water to clean, and 180 degree water to rinse. Knowing how well hot water works elsewhere in the building, we would have been lucky to have 100 degree water in the first round.

Two passes through the cafeteria dishwasher were enough to raise the cleanliness rating from a 5 to an 8. It’s still not perfect, but I wouldn’t be embarassed to have people using it. Now, we’ll just let it dry for a week, and see if it works.