Reglazing is completed through sprayers that professionals use. This spray, usually a mixture of polyurethanes and additives, coats the bathtub and starts to harden. The workers wear ventilators to protect themselves from the fumes and fully cover the bathroom in order to seal the air in and protect any fixtures that might accidentally be sprayed during the process.
From start to finish, the reglazing process itself can take between three and five hours. Most contractors should be able to finish the job within one working day, as long as the project involves only the bathtub. If your contractor says that the project will take longer, ask why -- sometimes a longer reglazing time means that the contractor is conscientious and prefers to reglaze slowly, which is a benefit in this delicate process.
The reglazing timeframe does not take into account preparation and finishing work. For preparation, you or the workers will need to move everything out of the bathroom except the fixtures -- you should also take out anything you might need in the short term. After the reglazing is finished the glaze needs to harden and the fumes need to dissipate. This can take around 24 hours after the process has been completed.
Not every reglazing project is the same, so take set timeframes promised by reglazers with a grain of salt. If you want to refinish more than just your bathtub, the process will take longer. If your bathtub is difficult to reach, large or needs extra repair work, this will all take extra time as well. Plan your schedule around the time appropriate for all the work that needs to be done.