Dip the brush into the acrylic liquid then immediately dip it into the acrylic powder.

Slowly apply the acrylic to the missing section on the neck a little at a time.

Caution: Be sure to work in a well ventilated room

Make sure the acrylic is not runny when applying.

Before it cools, you may use a toothpick to adjust and shape the acrylic to match the curvature of the neck (optional).