13.3 Gels: Application and Removal
Key Takeaways
Gel is a pre-mixed product of oligomers and monomers that cures when photoinitiators absorb light from a UV or LED lamp matched to that gel, for the time the product directs.
Standard gel types include bonding or base gel, building or hard gel, self-leveling gel, pigmented gel or gel polish, and top or sealer gel, and soak-off gels differ from hard gels at removal.
The tacky inhibition layer is the oxygen-inhibited surface left after curing; leave it between layers when the product requires it, and remove the last one with the named cleanser unless the top coat is no-wipe.
Under-cured gel sensitizes skin, a heat spike means the layer is too thick or the plate too thin, hard gel is filed off, soak-off gel is soaked in acetone, and neither is pried.
Gel is the second product system in outline item IV.A.2. Unlike acrylic, gel arrives pre-mixed in a jar, bottle, or tube and stays workable until light cures it. The steps below are standard nail-technology instruction from the Milady reference Pearson VUE lists. Pennsylvania Chapter 7 does not set a cure time, a lamp type, or a gel brand. The ventilation rule in 49 Pa. Code § 7.91 still applies to filing dust and product vapor.
What gel is and how it cures
Gel is a blend of oligomers, short chains of molecules, and monomers, with photoinitiators. When the photoinitiators absorb light of the right wavelength, they start polymerization and the gel hardens. That is why the lamp must match the gel. A UV lamp and an LED lamp emit different wavelengths, and a lamp that does not match the product can leave gel under-cured even when the surface feels firm. Cure each layer for the time the product and that lamp require. Do not apply one cure-second number to every system.
UV bulbs lose output with use even while they still glow, so follow the lamp manufacturer's replacement schedule. Keep gel containers closed and out of sunlight and lamp light, because light can begin curing gel in the container.
Standard gel types
| Type | What it does |
|---|---|
| Bonding or base gel | Thin first layer that helps the system adhere to the prepared plate |
| Building or hard gel | Thicker gel that builds strength, length, and the apex; usually filed off rather than soaked |
| Self-leveling gel | Flows into a smooth surface on its own |
| Pigmented gel or gel polish | Adds color; gel polish is a soak-off color coat |
| Top, gloss, or sealer gel | Seals the surface and adds shine; some leave an inhibition layer and some are no-wipe |
Soak-off gels are formulated so acetone can penetrate and soften them. Hard gels are more tightly cured and are removed mainly by filing.
Applying gel
- Prepare the plate as for any enhancement: clean, remove dead cuticle, remove the surface shine, and dehydrate. Use the bonding product or primer the system names.
- Apply each layer thin, keeping a clean margin at the cuticle and sidewalls, and cap the free edge.
- Cure each layer under the matched lamp for the directed time.
- Build the apex over the stress area with a building gel when strength or length is needed.
- Finish with the top gel and cure it.
Keep each brush with its own product and away from light. Wipe gel brushes with a lint-free wipe or the cleaner the manufacturer names. Do not clean a gel brush in acrylic monomer.
The inhibition layer
After curing, many gels leave a tacky surface called the inhibition layer. Oxygen in the air keeps that thin surface from fully curing. Leave it between layers when the product requires it, because the next layer bonds to it. Remove the final tacky layer with the cleanser the product names, often alcohol, unless the top gel is a no-wipe formula. Do not touch it with bare fingers, and do not wipe it onto the client's skin.
Heat spikes and under-curing
Gel polymerization also gives off heat. A heat spike is a burst of heat the client feels under the lamp, most often with a thick layer, a fast-curing lamp, or a thin, over-filed plate. If the client feels heat, have the client slide the hand out of the lamp for a few seconds, then return it, and use thinner layers on that client. Do not tell the client to hold still through the burn.
Under-cured gel is a sensitizer. Uncured gel on skin, or gel that never received a full cure, can cause an allergy that later services trigger. Many gels contain methacrylates, such as HEMA, so a client with a methacrylate or acrylate reaction is refused gel systems in that family. Wipe any gel off the skin before curing.
Removing gel
Soak-off gel and gel polish: file away the shine and break through the top layer so acetone can reach the color and the gel beneath. Soak the nails in acetone in a bowl or with acetone-soaked cotton and foil wraps for the time the product directs. Push the softened gel off gently with a wooden pusher, and re-soak whatever stays firm.
Hard gel: reduce it by filing with a hand file or an electric file, leaving a thin layer over the natural plate rather than filing into keratin. Hard gel does not soften reliably in acetone.
In both cases, never pry or peel gel off. Peeling removes layers of the natural plate along with the product.
Scenario: a hot finger and a dim lamp
A client says one nail burns a few seconds into the cure. The builder layer on that nail is thick, and the plate was over-filed at a previous salon. Have the client slide the hand out briefly, then finish the cure, and use thinner layers on the remaining nails. The lamp in use is UV, but the gel's label calls for LED, and an earlier set lifted early. Switch to the lamp that matches the gel, cure each layer for the directed time, and remove the final inhibition layer with the named cleanser. At removal, break the top seal, soak the soak-off gel in acetone, and push off only softened product.
A gel layer has been cured and the surface is still tacky. What is that layer, and how is it handled?
A sign that the gel must be pried off and replaced with MMA liquid
Filing dust that should be brushed onto the next nail before curing
The oxygen-inhibited surface, kept between layers if the product says so
Leftover primer, which means the lamp can be skipped on the next layer
How are hard gel and soak-off gel removed in standard instruction?
Both are pried off with nippers once the free edge starts to lift
Both soften in warm water if the client soaks for a full hour first
Hard gel soaks off in acetone, and soak-off gel must be filed away
Hard gel is filed down, and soak-off gel is broken through and soaked
A client feels a sudden burning heat a few seconds after a thick builder gel layer goes under the lamp. What should the technician do?
Turn the lamp to its highest setting so the cure finishes faster
Have the client slide the hand out briefly, then use thinner layers
Tell the client to hold still, because the heat ends once it cures
Add a second thick layer at once so the heat spreads more evenly
Why must the curing lamp match the gel system being used?
Pennsylvania Chapter 7 requires one lamp brand in every nail salon
A matched lamp lets the inhibition layer stay on the client's skin safely
A mismatched lamp can leave gel under-cured, and under-cured gel sensitizes
Any lamp works, but a matched lamp is needed only for gel polish colors
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