1. Excessive film thickness.
2. Improper dry. Insufficient flash and dry time.
3. Using the thinner which evaporates too fast
4. Using the spray paint which is too thick in compound
5. Primer has not dried thoroughly or pin holes existed since the prime layer
1. Allow ample flash and dry time
2. Each spraying should not be too thick
3. Select the Thinner which suits the temperature
4. Adjust the viscosity of paint according to working environment
5. Allow the primer to dry perfectly. If pin holes exist, fix with putty and refinish.
1. For few pin holes, sand down with an extra-delicate remover and refinish.
2. In extreme cases, scrape the film off and refinish.