What’s really going on when your client puts her hand in the nail lamp? We explain what gel is made of and why it works so well.
Gels — The Basics
GELS: pre-mixed semi-solid monomers and oligomers that are hardened to polymers when exposed to UV-A light.
Energy curable resins: a semisolid oligomer with at least one acrylic functional group that cures via light energy.
Photoinitiators: ingredients that absorb light and convert it into the energy needed to drive the polymerization process.
Stabilizers: chemicals that are added to prevent discoloration.
Inhibitors: ingredients that prevent the gel from prematurely hardening or pre-polymerizing while still in its original container.
Pigments (optional): insoluble, finely ground substances that impart color. Certain pigments (like white pigments) reflect some of the light that is used to cure the gels, while others (like black pigments) absorb some of UV light, and some just don’t cure well at all (many pigments fall under this category). It takes significant research to determine which pigments should be used for UV nail gel.
Non-energy curable resins (optional): functional fillers added to modify the properties of the gel, such as thickening or toughening the product.
Solvents (optional): substances in which other substances are dissolved. Brush-on gel polishes tend to incorporate an increased amount of solvents to help them break down faster than traditional soak-offs.
GEL NAIL LIGHTS: a light, generally containing multiple bulbs, that emits light in the correct spectrum to activate the photoinitiator in the gel. Most gels contain photoinitiators that react in light wavelengths of 340 to 380 nanometers (nm.).
Lamp (bulb) intensity: intensity refers to how much light is available for curing. Some people mistakenly think wattage is synonymous with intensity but it’s not — wattage is irrelevant to the science behind gels and simply refers to how much electricity the bulb uses.
Number of lamps: gel lights generally house from one to five lamps; three or four lamps is most common.
Light unit size: how close the lamps are from the fingernails makes a huge difference in a light’s ability to cure gel. In general, every time you double the distance between you and a light source, the intensity drops by 75%. (That’s why flashbulbs on cameras don’t help if the subject is far away.) A gel nail held one inch from a UV lamp receives three times more light energy than one held two inches away. (This is also why occasionally looking at a gel nail light from several feet away for brief periods poses virtually no risk to your or your clients’ eyes.)
Next page: UV v. LED and Bulb Change Schedule