Put on your goggles and prepare to enlarge the crack. Using the utility knife, you can gently cut away at the cracked or chipped area. Do not apply much pressure since the plaster has already begun chipping, and it will be very easy to remove more for a larger surface area to fill in.
Rough up the area with sandpaper to create more friction for the new plaster to bond with the existing plaster. Wipe away all loose dirt and dust with a soft-bristled brush so that you do not peel off or force any plaster off of the statue.
Combine the plaster powder and water in a bucket, and then stir with a wooden dowel.
Let a sponge soak up water, and then squeeze some water out and let the sponge sit on the area to be repaired. You can apply the new plaster once the hardened plaster is no longer soaking up any water.
Let the statue dry and cure for 24 hours before applying the primer.
Spray on the primer. This will protect the statue from natural weathering and staining over time.