Roughen the tips of the pipes and clean with Acetone or Nitro Thinner. Apply the glue evenly with the brush. Before the glue dries, press the pipe into the fitting and hold for 30 seconds.  Wipe off the excess glue. The pipes must be steady for at least 30 minutes. The final pressure test can take place after 24 hours. Close the container after use and keep in cool place.