Lume & Why It’s Part of Any Good Watch Repair Tool Kit

lume - Maddisons UK

If you look inside the average watch tool kit, you’ll usually find something called Lume, which was invented in the early 1990s. Experienced watch enthusiasts will likely know all about it and what it does, however, for the uninitiated, it’s an innovative viscose paste-like substance that’s painted onto watch faces and hands to make them glow in the dark.

Often available as part of a lume kit the paste is easily applied with the right watch repair tools. Lume is applied directly onto the numerals, watch hands and other areas of the watch face and this instantly refreshes the watch’s glow in the dark capabilities.

So, What is Lume Made Of?

Lume is short for ‘photoluminescent glowing solution’ and it usually contains strontium aluminate which is a non-radioactive substance that absorbs light during the day and emits it when it’s dark. Believe it or not, prior to Lume being invented, previous forms of the substance contained the radioactive element radium, which has all but stopped in the modern day due to the health risks associated with radiation.

Typically speaking, after absorbing light for as little as 30 seconds, watch parts that have had lume applied will continue to glow strongly for 3-5 hours. Application requires fine watch repair tools to be used, and calls for steady hand, as the areas that need to be painted are very small.

How Do You Know It’s Time to Re-Lume?

A good quality lume should last many years, but it’s usually pretty obvious when it needs to be reapplied. What you’ll find is that even when given a full charge, it will either not glow at all in the dark or be very dim when compared to how it should be glowing. 

Once you have the requisite equipment for the job, which will usually include the luminous powder, a tray with a dust cover, painter’s tape, a mixing bowl and a toothpick or other watch repair tool meant for fine work. Getting the job done will include removing the old lume, mixing the new lume, reapplying it and leaving it overnight to dry.

Quality Watch Repair Tools for Any Type of Task

Having lume in your watch repair tool kit along with your watch screwdrivers and case opener means that you’re prepared for every type of repair job that’s required. Many watches feature luminous watch hands, numerals and faces, so it stands to reason that it’s a job that’s going to come up – so make sure you’ve got some handy!

At Maddison of Durham, we offer a wide range of watch repair tools for both professionals and enthusiasts, which you can see by visiting us online at We’re on hand to answer questions you might have too and you can get in touch by emailing us at 

Upon receipt of your query, we’ll get back to you as soon as we possibly can. Thanks for reading. We’ll be back again soon with more hints, tips and advice next time.