Most nail professionals don’t think of themselves as the scientific type. We tend to be artists, wired for creativity, or social butterflies. In fact, there’s a lot of science that goes into everything we do. Salon products use sophisticated chemistry to create beautiful, durable nail coatings — including gels.
When you look at the range of gel products, there are a lot of choices, each with subtle differences that make them ideal for different situations. You have hard gel, soft gel, gel-polish, transformation gel, and more. To keep things as simple as possible, let’s take a closer look at these four main types. But first we need a basic understanding of UV gel as a whole.
“Most of the chemistry underlying the UV gels currently on the market revolves around crosslinked methacrylates,” says Chad Conger, senior director of R&D for OPI. “This is the same general type of chemistry used in the dental industry for UV-cured cavity fillings. On a molecular level, when these methacrylate materials polymerize (cure), they form crosslinks, which in a very general sense would form a net-like structure. The tighter that net is, the harder and stronger the gel. Also, the tighter the net, the more chemically resistant the gel will be, making it more difficult to remove.”
“Gels work by using reactive resins that are terminated with acrylate reaction sites (they cure in light instead of air) which are combined with chemicals called photoinitiators,” explains Jim McConnell, president of Light Elegance. “Once the gel containing the resins and photoinitiators is exposed to the proper light wavelength and intensity, the gel reacts to form a polymer — this is called polymerization. This is the same type of reaction that acrylics undergo, but acrylics use a peroxide in the powder to polymerize the resins, rather than the light and photoinitiator.”
Based on what we learned above about UV gels, you can see that a hard gel would have the heaviest crosslinking. The hard gel is designed to support its own weight if used to create an extension, as well as withstand average user wear. According to Conger, these products are normally nearly 100% reactive materials (which means they undergo a chemical change), so there is very little, if any, solvent or polymer. This is why the hard gels are chemically resistant when it comes to removal. It also makes them ideal for clients who regularly immerse their nails in water and other chemicals without gloves.
Removing hard gels is very simple, according to McConnell. “Don’t remove them all the way; file the hard gel to make it thin, but don’t file to the natural nail.” He advises using a foamy sponge file or buffing block to create a natural shine on the gel remaining on the nails so that they appear to have all the gel removed. Then allow the gel to grow off the fingernail. “It’s best to schedule a follow-up appointment with the client to inspect the condition of the fingernails after three to four weeks,” he says.
Soak-off or “soft” gels have traditionally been a weakened version of hard gels. This allows them to be removed with acetone after some filing of the surface of the product. “The solvent (acetone) will attack some of the resins that are used in the formulation of the soak-off system, resulting in the destruction of the soak-off gel product,” says McConnell. However, when the crosslinking is reduced making the coating easier to remove, some strength is sacrificed. There are a variety of resins that can be used in soak-off gel products and these variations account for the major differences between soak-off products. “If you tint the soak-off gel, it becomes a soak-off gel-polish,” McConnell notes.
The typical removal process for soak-off or soft gel is to file the product down by 50%-75%, then wrap or clip the nail, depending on your preferred method, for 20 minutes with an acetone-based remover. Check the first nail and if the product does not slide off completely, reapply the remover in five-minute increments.
According to Doug Schoon of Schoon Scientific, there are two types of UV gel-polishes: those that contain volatile solvents and those that don’t. The ones that don’t are essentially soft gels with color added. “Gel-polishes share a similar chemistry with other types of gels, but the formulations are created to work in multiple layers — base coat, color, top coat — that can have very different properties,” says Conger.
Base coats tend to be more of a blend of reactive methacrylates, film-forming polymers, and solvents that have very low crosslinking. Color layers vary widely from company to company but have a medium level of crosslinking, allowing the product to be flexible and removable, but still durable. Top coats tend to be more highly crosslinked, allowing for protection and shine. “This is why you’re told to file the top coat to remove many gel-polish products, since top coat formulations can be challenging to remove,” Conger says.
Read the instructions for your particular gel-polish brand to see if filing the top coat is required as a first step to removing the product. Then wrap or clip the nails using your preferred method for five to 15 minutes with an acetone-based remover. The removal time will vary by product, so be sure to follow the manufacturer’s instructions for the best results. Check the first nail and if the product does not slide off completely, reapply the remover in five-minute increments. You can use a remover-soaked pad to gently rub off any remnants of base coat. Buffing or scraping off the small bits of remaining product can result in white spots, which are an indication of damage to the surface of the nail.
Called “transformative” or “transformation” gel, these products can be mixed with your favorite nail polish to create a custom gel-polish. They use gel resins — ones that are vulnerable to attack by acetone like soak-off gels— that are compatible with nail lacquer. Because of the altered balance of ingredients (like photoinitiators, resin, and pigment), you may not get a consistent cure with every color you make, or experience the same wear you’d expect from a gel-polish; however, it does offer the novelty of creating colors.
Transformation gel-polish mixes are removed in the same way as any other gel-polish. Again, check with the specific manufacturer for ideal soak-off times.
When it comes to removal of any soak-off gel or gel-polish, the removal time from your manufacturer is a minimum, not a maximum. The method of removal, the temperature of the salon and your client, along with the thickness of your application and how much you file off, are all going to play a part in the removal time and process. For each client, set a timer for the recommended time and view it as a starting point instead of a fixed and non-negotiable end point. Removing UV gel properly will minimize, if not eliminate, damage to the nails.
Read about avoiding heat spikes at www.nailsmag.com/heatspikes.
Read about scheduling time for safe gel removal at www.nailsmag.com/removaltime.
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