Mechanical keyboards used to be very common and popular in the 1990s and earlier, and for many people the feel and sound they gave more closely resembled the typewriters they might have been previously used to. Since then, the mechanical keyboard has given way to cheaply produced 'rubber dome' style keyboards, which will be familiar to us all. Generally, their keys are quieter, have little sensation (mushy), and smaller travel, which leads to a less satisfying typing experience.

Mechanical keyboards have enjoyed a comeback driven by gamers, who appreciate the better tactility and response of a mechanical keyboard, as well as some professional typists. However, mechanical keyboards are very often quite expensive (many models well over $100), and choosing one can seem tricky!

In this Instructable, I buy an old keyboard online, and restore it to be as good as new. Here's also a list of things you'll need to carry out the restoration:

Keycap puller, I recommend the wire type. Should be very cheaply available online.
Denture tables - these are excellent for making a solution to clean the keys.
Wet-wipes, cotton buds, paper towel - for cleaning the chassis of the keyboard.
PS/2 to USB converter - this will allow you to use the old keyboard if your laptop or PC only has USB inputs available, although many modern motherboards still support the PS/2 input. If you are purchasing a converter, it is important to search for an 'active' converter, rather than a simple one.

Step 1: Choosing and Buying Your Keyboard

There are a huge variety of old keyboards available, but one extremely common and good quality keyboard is the Dell AT101 family. They were a large series of keyboards from the 1990s, based on the Alps 'Bigfoot' series (so named because of their large size). I picked up a Dell AT102W, which was one of the last models, probably dating from 1998-2000.

Despite their age, as they were very solidly built they can last for ages, and luckily the materials chosen make them easy to clean. You'll definitely be able to pick up one of this range very cheaply online, and it makes a perfect beginner's mechanical keyboard! The switches used in mine are Alps SKCM Black switches, which are heavy (70g) tactile switches and they make a very satisfying sound when used. The keyboard has a nice weight, so won't move when typing, and I appreciate having a full-size board.

This Instructable just covers cosmetic cleaning, it does not cover the repair of a non-functioning keyboard, so make sure that the example you are purchasing (however filthy!) is at least functional.

Step 2: Removing the Keycaps

Over the decades keycaps will often yellow, and will pick up nasty grime and grease. Let's clean these to make them good to look at and hygienic. To start with we'll need to remove them all from the chassis. Being a full-size keyboard this might take you a little while! You'll need a keycap puller (the wire variety is best).

Gently hook the wires of the keycap puller under opposite corners of each key. Give it a little wiggle, then pull directly upwards, and the keycap should 'pop' off, leaving the exposed switch below. Be very careful not to remove them at an angle, as you might break the stem of the keycap (I did this with one key, I'll mention how I fixed it in a later step of this Instructable). The large keys such as spacebar, enter, backspace etc have a wire assembly beneath them as well to give better support. These are slightly harder to remove, just make sure you pull directly upwards. The wire clip is held in with some small plastic fasteners, which are friction-fitted into the keycap body and the chassis. These might be pulled out as the keycap comes away, but they are easy to push back into place.

Gather the keycaps in a big pyrex mixing bowl or something similar, ready to be cleaned. Don't rush taking the keycaps off, it's better to relax and avoid causing any damage.

Step 3: Cleaning the Keycaps

Now we've removed all the keycaps from the keyboard chassis, it's time to clean them. A commonly recommended method is to soak them in a mixture with denture tablets, which for me proved to be very effective.

Take your mixing bowl with the keycaps in, and fill with warm water. Now place four denture tablets in too. They'll fizz and bubble and make a weird-looking green potion, with your keycaps floating around in. Make sure all the keycaps are submerged, and now leave for about 24 hours.

24 hours later your house will smell like a dentist's surgery, but you'll have a set of very clean keycaps! Rinse them off with cool water, catching them in a sieve, and place them out to dry. Don't try to accelerate the drying process by applying heat, you might risk warping them.

Step 4: Cleaning the Chassis

Whilst you're waiting for the keycaps to soak, you can clean the chassis. As you removed the keycaps, you'd have found lots of fluff and dirt and things beneath the keycaps, around the switches, so we'd better clean it up.

Giving the keyboard a good shake upside-down outside will partially help, although you'll need to sit down and meticulously clean around the base of each switch using the wet wipes and cotton buds. Takes a little time, and you won't be able to remove absolutely everything, but it can make a big difference. Be careful not to get the keyboard wet, apart from the small amount of moisture from the wet wipes.

After this you'll need to turn your attention to the plastic case of the keyboard itself. With mine I found that a solid scrub with the wet wipes removed all the marks and stains that were visible! It was very satisfying to be left with a nice clean board.

The wet wipes also did an excellent job of the keyboard's cable, the wipes removed all marks and stickiness, leaving it looking as good as new.

Step 5: Reassembly

When the keycaps are dry and you've finished cleaning the body of the keyboard, it's time to reassemble. Luckily it's much easier to put together again that it was to take apart. The keycaps can be reattached to the switches with a gentle push downwards. With the large keys, make sure the wire support is in place, and then again push directly downwards onto the switch.

So there we go! You've got a nice mechanical keyboard for very little investment, and after this clean it should be as good as new. I typed this instructable up on my newly-cleaned 'Bigfoot', and look forwards to using it much more.

Note: when removing the keycaps it can be quite easy to accidently break the stem (the bit of the keycap that fits into the switch). I accidently did this on one key, but luckily there's no need to panic, it's quite easily repairable. If your keycaps are made from ABS, like those on the AT102W, then ordinary cyanoacrylate superglue will work well. Apply a small drop of glue, and then place the keycap into position. Don't push down on the key, that might accidentally work the glue into the switch mechanism. Just leave it stationary for 24 hours, and then it should be totally usable.