As some of you might know, Fujitsu leafspring 3rd generation is a pain to clean due to the difficulty of removing the slider from the housing without breaking the slider. I didn't know this when I first bought my HP 46020A keyboard and gave up on restoring the initially quite scratchy switches after even hours of ultrasonic cleaning produced a lackluster result, but recently had an idea of cleaning them which doesn't involve seperating the switch housing from the slider. The result turned out suprisingly well.
Materials required for this are ethanol/isopropanol, ideally an ultrasonic cleaner and optionally PTFE powder (I used this one)
The method is quite simple:
- Soak the whole switch in ethanol for a few days, occasionaly stirring
- Put the switches into an ultrasonic cleaner (I just used undestilled water and dish soap, cleaning for 2 rounds of 15 minutes)
- Remove from ultrasonic cleaner and rinse with water to remove any soap residue
- Let the switches mostly dry over a few days (this step may be unnecessary)
- For the lubing part, add a bit of ethanol and PTFE powder to a sealable container (I used about 40ml of ethanol and 0.5g of PTFE), then shake to create a PTFE ethanol suspension
- Add the switches to the container with the suspension and shake for a while (about 15 minutes in my case)
- Let switches dry (took only about a day)
The result are switches which are completely covered in a very fine layer of PTFE and are extremely smooth without any of the sluggishness often caused by greasy lube. My only concern is that some of it might come loose during usage so this method could be problematic with switches which have more exposed contacts.