Does it ever feel like your front door lock is sticky? The lock itself might work (albeit stiffly), but when you insert your key inside, it's almost as though there's some kind of adhesive in there. Ideally, you would be able to disassemble your door lock and give each component a thorough cleaning, but you might not have the tools or knowledge to do this. So what generally causes a sticky lock, and what can you do about it?
A Buildup of Lubricant
The likelihood is that the issue is caused by a buildup of lubricant inside the lock. The lock would have been lubricated prior to its installation, and you have probably added lubricant yourself over the years. This lubricant is essentially trapped inside the inner workings of the lock, meaning that it doesn't quite dry out. Minuscule amounts of lubricant can attract dust and other types of debris, which then combine with the lubricant to create something akin to a tiny gelatinous lump of dirt. This is what is catching your key as you insert it into the lock, resulting in that annoying sticky feeling.
Lubricating Gels and Sprays
You might think that additional lubrication will restore your lock to perfect working order once again, but it can in fact make the situation worse. Please do not attempt to fix a sticky lock with any kind of lubricating gel or spray. You will need a dry powder for this job.
Graphite powder can be obtained from any hardware shop. The applicator comes with a thin nozzle that you apply by gently squeezing the container, expelling the graphite outwards. This means that it's not a good idea to do this on a windy day. Hold the nozzle to the door lock and gently squeeze. Insert and remove your key a few times to distribute the graphite powder throughout the different components of your lock. It will allow your lock to function properly, and the powdery composition of the product means that it will not accumulate dust. If you cannot locate any graphite powder, just use a pencil. Carefully split the pencil along its length and remove the dark graphite centre. Pulverise this with the back of a metal spoon and apply it to your key. Insert the key inside the lock and jiggle it to distribute the powder.
Graphite powder will probably fix the issue, but if your lock still feels sticky, it will need to be cleaned. Call a mobile locksmith who can quickly visit you to disassemble your door lock and give each component a thorough cleaning.