Gel Nails and UV/LED Curing
Gel questions test whether you understand that curing is a chemistry event, not a timer. The exam asks about gel types, lamp matching, layer thickness, safe removal, and the allergy risk from uncured product on skin.
Types and curing
- Base gel bonds to the plate; builder (hard) gel adds structure; color gel provides pigment; top gel seals and provides shine. Soft gels soak off in acetone; hard gels must be filed off.
- UV lamps emit roughly 350–380 nm; LED lamps roughly 365–405 nm. Photoinitiators differ between systems, so a gel must be cured with a compatible lamp and the manufacturer's time.
- Cure time depends on lamp intensity, layer thickness, and pigment load. Dark, opaque colors and thick builder layers need more time; stacking two clients' hands or crowding fingers under the lamp under-cures.
- Keep lamp bulbs and reflectors clean, replace bulbs as specified, and never assume a lamp still performs because the light appears bright.
Safety and removal
- Uncured gel on skin is the main route to acrylate allergy (often to HEMA). Keep product off skin entirely; wipe the inhibition layer with the correct cleanser; never peel or pick gel, which tears plate layers.
- Removal: file through the top coat, wrap with acetone for 10–15 minutes, then gently remove softened product. Do not scrape hard.
- A heat spike during curing means the layer is too thick; remove the hand, then rebuild in thinner layers.
Worked example
A client's gel polish peels off in sheets within a week. Reasoning: the color was applied too thick so the lower layer never fully cured; the base was incompatible with the lamp; or the plate was not properly prepped and dehydrated. Peeling in sheets points to under-cure and poor adhesion, not to weak nails. The correction is thin layers, matched lamp, full cure time, and correct prep.
Traps that cost marks
Believing any LED lamp cures any gel; mixing brands and blaming the product; extending cure time to rescue a too-thick layer; and permitting gel on skin as "it wipes off."