BASE CNI Poly Gels Nail Up. The first step in the Nail Up system. Provides strong adhesion of the natural nail to the polygel and helps to avoid detachment. The Nail Up base is an LED base, it is quite viscous, does not flow under the side rollers and self-leveling on the nail. The base should be applied to the UltraBondex primer and cured in any type of lamp for 60 seconds.