What does ‘overcured’ really mean?

“I have been taught that over-cure means you cure a nail product in a uv lamp longer than a manufacturer prescribes / recommends. I understand what happens when a nail product is not cured long enough. But let’s say, a nail coating has to cure for 30 seconds to proper cure – what will happen if I work per 1 or 2 fingers? If a proper cured product goes into the light again (and again and again…) and get another full cure? Is that also overcure? It’s not possible to cure a product 180%, am I right? Will the ‘extra’ cure cause any problems?”

Thank you for your question! It is a good one.

‘Overcure’ does not mean too long in the lamp. Once a coating is properly cured it will not cure any more. All but a small percentage of monomers have polymerised. The few that are remaining cannot move around anymore to form polymer chains, but they will not be a problem during removal.

This is why it is fine to keep replacing the nails in the lamp for further layers. So, in this sense you cannot ‘overcure’. Also, nails are in daylight and sunlight and this will not affect it for the same reason.

What ‘overcure’ means when thinking about the ‘proper cure’ is when the polymerisation process is too fast, and the exothermic reaction (heat) can be felt and possibly burn the nail bed.

This can happen if a UV lamp that is not matched to the UV gel system is used so the UV energy is too high. Or it can happen if the coating is too thick so the level of monomers in the process is so high that the heat can be felt. Or it can happen if the nail plate is very thin making the nail bed sensitive.