You can apply as many coats as you want for build. Just keep in mind that the more you apply at once, the longer it will take to dry enough to sand well. Normally when using it for build, I apply 3 wet coats with an hour or more in between. Use a 1.5-1.8 tip gun and mix the epoxy the night before. It will dry sand best after at least 48 hours when doing this. 72 hours even better.After this next round of epoxy how long should I let it dry before blocking? How many coats should I do for building on it?