What is used to soften PVD pipe and remove the gloss?

The process of softening PVD (polyvinylidene fluoride) pipe and removing the gloss is primarily achieved with the application of primer. Primer is a specific type of solvent that prepares the surface of the pipe for bonding by softening it slightly and allowing for better adhesion of the glue that will be applied afterward. The primer also helps to enhance the bonding process and provides a suitable surface for the glue to adhere to, ensuring a strong and lasting connection.

Using sand cloth, while it can indeed roughen a surface, does not adequately soften the pipe nor effectively remove the gloss in the way primer does. Glue, on its own, does not perform the needed surface preparation that primer does, and acetone, although a solvent, is generally not recommended for PVD pipe as it may not provide the necessary surface treatment required for achieving a good bond.