This page describes the various cleaning methods and materials for a range of different situations.


A significant number of faults are simply due to dirt, dust or corrosion interfering with either the mechanical or electrical operation. Different techniques, cleaning agents and tools are available, applicable to different situations, reviewed here.


Some cleaning agents may irritate the skin or give off inflammable or toxic fumes. Always read the label and work in a well ventilated location if fumes are a potential hazard.
Always ensure any electrical device is unplugged before attempting any kind of cleaning, to avoid the possibility of electric shock, or physical injury if it were to unexpectedly start running.


There are lots of different cleaning agents (many of them proprietary formulations of the same basic ingredients), there are lots of cleaning tools, and there is no shortage of cleaning situations you might be faced with. Here are some we've found useful in the Restarters community.

(You may have your own favourite cleaning tips. Please edit the page yourself or click on the Discuss tab above, then under Other, click Edit Discussion. Add your ideas. No requirement for polished English or well-thought-through contributions in Discussion pages.)

Cleaning Agents

There are many proprietary cleaning agents, but here we mainly concentrate on generic ones. Note that some are flammable or may cause skin irritation. Always read the instructions.

  • Isopropyl alcohol (also known as IPA or rubbing alcohol).
Very useful for general cleaning, e.g. for removing fingermarks and general grime, excess flux from circuit boards and for cleaning glass and lenses.
  • Switch cleaner, e.g. Servisol Super 10.
Good for dirty or corroded switch or battery contacts.
  • Air duster aerosol can.
Not very environmentally friendly (an air puffer is preferred) but can be useful if a strong blast is needed to dislodge dust from tight corners such as under the keys of a keyboard or between the vanes of a heatsink. Most contain a gas, in some cases flammable, under sufficient pressure to liquefy it. If not held roughly vertically you may get a squirt of liquid instead of a blast of air.

Cleaning Tools and Materials

A variety of tools are useful for cleaning, some in conjunction with cleaning agents mentioned above.

  • Air puffer.
Preferable on environmental grounds to an aerosol can duster though not as powerful. Useful for blowing dust out of tight corners such as under the keys of a keyboard, or between the vanes of a heatsink.
  • Vacuum cleaner.
You can use a domestic vacuum cleaner with a crevice nozzle or a hand-held portable one. Unlike an air puffer or air duster aerosol can, it sucks dust out rather than simply blowing it somewhere else. Especially useful for heavy build-ups of dust.
  • Small brushes.
You can get sets of small brushes including a nylon one for light use, a brass one for more aggressive cleaning where you don't want to scratch a metal surface under the dirt, and a still more aggressive steel one. You might also want to get an antistatic one for cleaning circuit boards.
  • Needle file.
This can be useful for removing a heavy build-up of corrosion, though it may be too agressive in some situations as it may damage the surface underneath and leave it roughened.
  • Cotton wool buds.
Moistened with isopropyl alcohol, these can be useful for cleaning when there isn't room to get a brush in.
  • Paper kitchen towel.
Often useful to have a few sheets to hand to clean up any kind of mess or spillage or for wiping greasy fingers.
  • Lens cleaning cloth.
Useful for cleaning lenses, screens and glass generally, especially used in conjunction with isopropyl alcohol.
  • Camel hair brush.
This is a standard method of removing dust from a lens.
  • Screen cleaning wipes.
As above, but these are single-use and come pre-wetted with cleaning solution

Cleaning Situations

Battery contacts

A very common situation is a battery-powered device such as a toy or a radio which has had dead batteries left in it for an extended period. These will have leaked, corroding the contacts in the battery compartment.

First of all, clean off any chemical residue (usually white-ish) with a stiff brush and isopropyl alcohol. If there are still signs of corrosion, continue with more isopropyl or preferably switch cleaner fluid and a stiffer brush. If available, start with a brass brush, and only if necessary, resort to a steel one or a needle file or a piece of emery paper.

Switch contacts

Generally the advice is similar to battery contacts, particularly if moisture has caused corrosion. Otherwise, it will simply be a build-up of dirt which can be removed by less aggressive means.

Slide switches sometimes become unreliable due to dirt or mild corrosion. Usually you can squirt isopropyl alcohol or switch cleaner in each end then vigorously operate the switch a good many times in order to clean the contacts.


For an internal connector inside a device which has probably never been disassembled since manufacture, disconnecting and reconnecting it may be enough to restore a good connection.

If that isn't sufficient, try isopropyl alcohol with a cotton wool bud or soft brush. Make sure the cotton wool bud doesn't shed any threads of cotton which might then interfere with the contact.

Lenses and optical surfaces

If at all possible, it's best to prevent dust accumulation on a lens and to avoid fingermarks, as it's hard to get it absolutely clean. In cleaning it you may be generating static which attracts more dust. If you disassemble a camera or projector, take care not to get any dust on the optical surfaces. (If you were working with a high powered laser then you would know that the slightest spec of dust on a lens could absorb sufficient energy to burn a hole in it! And you'd have a duster incorporating a radioactive source to discharge the static. Needless to say, such things are not available to mere mortals like us.)

Some lenses have an anti-reflective coating. Mirrors, for example in a projector, are likely to have the silvering on the front side. In both cases, inappropriate cleaning materials or methods can damage this coating.

Photographers often use a very soft camel hair brush for removing light dust from their lenses. Lens cleaning wipes are pre-wetted with isopropyl alcohol and can be used to remove both dust and finger marks. Or you can use a lens cleaning cloth and your own isopropyl alcohol or lens cleaning fluid.


(Lenses and other optical surfaces are treated separately.)

Sand, dust and dirt can get lodged between the lens barrels of a compact camera. See our Compact Cameras page for how to remove it.


Dust, dandruff and hairs can accumulate under the keys of a keyboard. The first thing to do is turn it upside down and shake it, hopefully removing the worst. Next, go over it with hand-held a vacuum cleaner, or a full sized one with a crevice nozzle, though for safety, probably not on full power. (An air duster may simply move the dust around rather than blowing it out.)

The keys always accumulate finger grease in the course of use. You can clean the key tops and the surrounding parts of the keyboard with isopropyl alcohol on a soft cloth or tissue, but grime on the sides of the keys may be less accessible.

The key tops are usually removable, and if you can take them off (and remember where they all came from!) you can wash them in a bowl of warm soapy water. But beware, although some keyboards have key caps which simply pull off, in others (in particular membrane keyboards) the key caps clip onto a scissor mechanism. The key cap is designed to unclip either at the top or at the bottom of the key cap and then unhook at the other side. If you force it off on the hooking side you will break the pegs on the scissor mechanism and the key cap will no longer be properly retained.


Mice accumulate finger grease, which can be removed with isopropyl alcohol on a soft cloth or tissue, or a cloth soaked in domestic cleaner and then well wrung out.

In a mechanical mouse with a ball underneath, you can remove the ball for cleaning by twisting the retaining cover. Inside, you will see two wheels set at right angles, which are turned by the ball as you move the mouse. Look for any hairs wound around these or their spindles, and remove with a fine pair of tweezers. Also, attempt to clean the surface of each wheel with isopropyl alcohol on a cotton wool bud. To gain better access or to remove obstinate hairs you may have to disassemble the mouse, usually by removing the screws in the bottom.

Optical mice are less prone to such problems, but again, look for hairs which might be obscuring the optical mechanism.

The switches under the mouse buttons are required to operate many thousands of times and may become unreliable. Restoration by cleaning is not normally feasible but they can be replaced. In lower end mice they are cheap tactile switches but in higher quality and gaming mice, they are microswitches. A YouTube video goes into excruciating detail about the different sorts you can get.

Rubberised coatings gone sticky

A variety of devices are finished with a rubberised coating, including some laptops, mice and binoculars. This gives them a nice anti-slip feel, but it sometimes turns into a nasty sticky mess as it ages.

Mechanical removal may be possible. Scrape it off with some kind of scraper, taking care not to damage the underlying surface, possibly following up with some isopropyl alcohol.

Isopropyl alcohol is sometimes recommended as the first resort, but this isn't always effective and may just turn the coating into an even stickier mess. If so, paint stripper may work better, but first check on an inconspicuous part that it doesn't attack the plastic underneath. You will need to wear rubber gloves (don't expect to use them again for anything else!) and work in a well ventilated place.

The process can be somewhat time-consuming. Work on a section at a time. Apply the paint stripper liberally and leave it a few minutes to work. Then start scraping the coating away. You will probably want to try a variety of scraping tools, such as an old bank card, a blunt knife, or whatever you have to hand which won't scratch the plastic underneath. Wipe the scraper frequently with a piece of paper kitchen towel, and apply more paint stripper as necessary.

Once you have removed as much as possible with the scraper you can use more paint stripper and a paper towel. Finally, clean off remaining paint stripper and the last vestiges of the rubber coating with isopropyl alcohol and a paper towel.

Vacuum cleaners

First, empty or change the bag, or for a bagless model, empty the dust canister.

Check all filters. Check the instructions - there may be another filter you hadn't noticed. If they are clogged, the suction will be poor, and they will probably need replacing. Alternatively, you may be able to shake out much of the dust by banging them against a wall (outside) or washing them in soapy water then allowing them to dry.

An improperly fitted or damaged filter, or a damaged bag is likely to result in a great deal of mess inside the machine. You can most easily clean this up with another vacuum cleaner, or if that's not possible, take it outside and use a soft brush or cloth. If the dust has reached the motor you may need to clean the brushes and commutator. (See Electric Motors.)

An upright vacuum cleaner or one with a powered cleaning head has rollers which can get clogged with hairs around the brush. If they get around the spindle you may need a sharp knife to cut them away. If you can remove the roller it will make your job a lot easier.

Charge/sync and audio ports

These port on smartphones and tablets can be magnets for dust, dirt and fluff.

First of all, examine the port with a magnifying lens or eye loupe to see if there is any visible fluff or dirt. You may be able to remove it with a fine-tipped pair of tweezers. Alternatively, try to blow it out with an air puffer. A crevice nozzle on a vacuum cleaner may also do the trick.

Sometimes a heaphone jack will break off inside a headphone socket. A magnifying glass or eye loupe and a torch will help you to see it inside the socket, and see if there is any part of it you can get a purchase on with a pair of tweezers. However, you may not be able to get sufficient grip with tweezers. You may be able to dig it out with any sharp implement such as the point of a pair of school compasses or a seam ripper as used by seamstresses.

Liquid spills

Your priorities should be:

  1. Quickly remove as much water or liquid as you can with a towel or whatever else is to hand.
  2. If the water may have got into openings such as the charging or headphone sockets, vigorously shake it out.
  3. If the device still seems to be working to any extent, switch it off. If you possibly can, remove the battery.
  4. Place it in a warm dry place such as an airing cupboard for 24 or 48 hours with any removable covers off or battery compartment open.

For more detail, see Water Damage.

For liquids such as a beverage it may be helpful to flush out what remains with isopropyl alcohol, or use it to clean dried deposits.

A laptop keyboard may be quite difficult to rescue, but a replacement can often be obtained relatively cheaply and is often fairly simple to fit.

Sewing machines

Build-up of fluff is common problem, easily fixed. See our Sewing Machines page for how to clean and service a sewing machine.

Cooking grease

Wipe away what you can with paper kitchen towel.

Note where the electrics are, in particular where the power lead enters the device, and the location of any switches or controls. Take great care to keep water away from these. Under no circumstances, immerse an electrical appliance in water.

Add a generous amount of washing up liquid to a bowl of water, then soak a dishcloth in it. Squeeze it out thoroughly so that it won't drip. Use this to wipe away as much of the grease as you can, frequently rinsing the cloth.

For more stubborn grease stains, use a cleaner containing oxalic acid such as Bar Keeper's Friend. Place a little on a slightly damp dishcloth or scourer. (This is also great for removing rust stains and for marks on stainless steel.)

Once grease becomes carbonised it's much harder to remove. You can try oven cleaner and/or steel wool. You will need rubber gloves. Take care with steel wool as it may damage the underlying surface.

Hair dryers

If hairs enter a hair dryer they can get tangled up with the fan causing it to run slow or to jam. This in turn will cause the element to overheat.

Hairs are likely to enter at the back of a hair dryer where the air is sucked in. This should be covered by some kind of grill to prevent hairs entering. If you can remove it, for example by twisting or removing a screw, then you should be able to get at the fan. If there are hairs around the spindle, these will be harder to remove. You may be able to prise them off with some kind of pointed instrument or a sharp knife.

If you can't access the fan that way, or can't gain sufficient access, then you will need to disassemble the device. This may or may not be possible non-destructively, but if you succeed, take care to reassemble it exactly as it was.


If a printer is suffering from mis-feeds or jams it may be worth cleaning the rollers with isopropyl alcohol on a cotton wool bud. However, they may be hard to access and hard to rotate manually in order to clean the entire circumference. But check that your paper is bone dry and of good quality. If not, this may be the cause of your problems.

If you are getting marks or streaks on the pages, first try running several blank sheets through the machine. If that doesn't improve it you will need to try and work out where the ink is coming from. You may be able to wipe it away with a soft paper tissue, perhaps moistened with isopropyl alcohol. It may help to wipe excessive ink from the print head, if you can get at it. Check for any ink leaks, for example from a damaged or poorly fitted ink cartridge.

For a laser printer, consult the instruction manual. It should give you several things to try.

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