‘UV Lamps’ are considered outdated technology. They cure gels at a much slower rate. ‘LED Lamps‘ cure much faster, but there is a common misconception that they don’t contain UV – they do. Both UV and LED Lights emit UV Light. The name LED just refers to the different type of bulb used in an LED Light.

UV lamps use ‘CFL’ bulbs or ‘Compact Fluorescent Lamps’. CFLs must be replaced regularly as they lose the ability to emit UV and will stop working.

• If you have 30-40 clients a week, the bulbs need to be changed every four to six months.
• If you have 20-30 clients a week, the bulbs need to be changed every six to eight months.
• If you have under 20 clients, once a year should be sufficient.

If you notice the inhibition (sticky) layer on your clients’ nails getting thicker/more gooey even after the correct curing time is up or if you are seeing service breakdown (e.g. peeling or wrinkling of the gel), this is a strong indicator you need to replace your bulbs.

LED lamps, funnily enough, use ‘LED’ bulbs or ‘Light Emitting Diodes’ rather than the fluorescent tubes used in traditional-style CFL/UV lamps. LED bulbs do not need to be replaced.

Bulbs aside, both types of lamp (as in, the entire unit) will probably need replacing after 3 years of normal use.

Measuring UV Light – Wavelengths and Intensity

Light is measured in two values: wavelength (measured in nanometers or “nm”) and intensity (measured in milliwatts per square centimeter “mW/cm²”).

It’s easiest to think of UV light as coming in a few different flavours. These flavours are known as wavelengths, and the strength of that flavour is known as intensity.

Wavelengths (different flavours) are shown below in the Electromagnetic Spectrum. Each number (shown at the bottom of the image) is a flavour –

Within a given wavelength (flavour) of UV light, there is a variance of UV light intensity (flavour strength). Just as someone might have added way too much cocoa (or not enough!) to chocolate ice cream, so too the intensity of light can be affected by different things, for example –  –

• The wattage of the bulb e.g. the difference between a 25-watt bulb and a 75-watt bulb – you know that if you put a 25 watt bulb in your lounge vs a 75 watt bulb the brightness or intensity will change. The same happens if you put a 4 watt vs a 9 watt bulb in your Gel Lamp.
• The number of bulbs e.g. you know that if you put four 75 watt bulbs in your lounge vs 10 of them, the brightness or intensity will change. The same happens if you put 4 bulbs vs 12 bulbs in your Gel Lamp. The more bulbs, the more UV intensity the lamp will emit.
• How far the bulbs are from the fingernails e.g. you know that if someone shines a torch on your from several metres away, the light will disperse. If they shine a torch on you from 10cm away, the light will be intense enough to see every pore and freckle on your skin. The same happens if you put your bulbs 5 cm or 10cm away from the hand in your Gel Lamp. The further the bulbs are away from the gel, the slower the gel will cure. If the bulbs are far away, the gel may not even cure at all just as you may not have been able to see a single freckle on your skin.

Narrow Wavelengths

LED lights use a wavelength (back to flavours) that is much narrower than that of CFLs. This narrow wavelength emits just the right amount of the specific UV-A wavelength that’s needed to cure LED gels, which is why LED cures faster.

Think of it like this – if you need 2L of strawberry ice cream but the shop only sells tubs of Neopolitan (the one that has a stripe of chocolate, a stripe of strawberry and a stripe of vanilla), you’re going to need to buy multiple tubs to get enough strawberry. If they sold tubs of just strawberry, you’d only need one and be done much more efficiently.

LED Lamps ‘get to the point’ in the same way, giving you only what you need.

In more technical terms, most gels require the use of somewhere between 340 to 380 nm to cure, but it will be very specific from brand to brand – e.g. one brand might cure at 350 nm while another might cure best at 375 nm.

• A CFL/UV lamp intended to cure a gel that is rated for 350 nm will emit a wavelength ranging around 80 nanometres, from roughly 320 to 400 nm. This is the ‘Neopolitan’.
• An LED lamp intended to cure a gel that is rated for 350 nm. will use bulbs that emit from only 345 to 355 nm. This is ‘plain strawberry’. The emission is much more precise/narrow.

Note that most of the ultraviolet light emitted by gel lamps (whether they’re marketed as UV or LED) is UVA. UVB is the wavelength that causes skin damage and tanning, therefore our lamps cannot do that – the common client joke about getting a tan on their hands is impossible in actuality.

• Although UV/CFL Lamps emit a wide spectrum of light, the bulbs contain special internal filters that remove almost all UVB.
• With LED Lights, a lot of the lights on the market are 405 nm or close to, which is very near the top end of the UVA spectrum, in the violet spectrum – well away from the UVB spectrum. These rays emit at a higher intensity/strength but the wavelength is less damaging to the skin because the violet spectrum does not cause skin damage.

Interestingly, this higher intensity means LED nail lamps actually emit more UV light than UV/CFL lamps with fluorescent bulbs, which is again why they cure gels faster. This doesn’t mean they’re less safe. LEDs emit fewer UV wavelengths overall (because they are narrow) but those wavelengths have a higher intensity. CFLs emit many more wavelengths but at lower intensities, and for longer.

UV versus LED products

Some gels are specifically marketed as UV(CFL)-Only or LED-Only.

The big difference between these products is the photoinitiators, or the molecules that initiate/start the chemical reaction that causes hardening (‘polymerisation’). Certain photoinitiators are used for LED gels, while the photoinitiators used for traditional UV gels are different.

Some manufacturers, including Artistic, have calibrated their gels to work well with both UV/CFL and LED lights, but there is no such thing as a gel that will properly cure with any lamp, nor is there a nail lamp that will properly cure every single brand of gel.

It is important to remember that the nail manufacturer knows what intensity is required to cure their specific gel product. So, if a gel manufacturer says that its gel requires two 4-watt bulbs to cure the gel, this will be sufficient. However, if a manufacturer has determined that its gel cures best with six 8-watt bulbs, do not attempt to cure the gel in a weaker lamp. The gel will become a solid plastic, but as discussed in the next text (‘The Dangers of Improper Curing’), the resulting plastic will not be as hard or as durable as it would be if cured in the correct lamp.

Did you know? LED Lights have about 30% lower wattages, meaning they use about 30% less electricity. Wattage is NOT an indication of how much UV is released.

Source: http://www.nailsmag.com/article/93494/the-differen…