Depending on your tub’s condition, a standard in-house refinishing should take two to five hours. Factoring in time for the tub to dry, expect at least a day, perhaps two, for the entire process to be complete before you can use the tub. Re-glazing will take days or even weeks. If your tub has damage, excessive wear, or has been refinished before, the process can take longer. A contractor can give you more precise estimates.