What typically happens if water is used to sand polyester-based putty?

Using water to sand polyester-based putty can lead to the putty absorbing moisture, which significantly affects its adhesion properties. Polymer-based fillers, like polyester putty, rely on a chemical process to cure and bond to surfaces. When water is introduced, it can infiltrate the putty and create an environment where proper curing may be hindered. This moisture can lead to a weak interface between the putty and the substrate, potentially resulting in delamination or failure of the bond over time.

The potential risks associated with moisture absorption include reduced adhesion strength and compromised structural integrity of the repair. Proper sanding techniques typically involve using dry sandpaper to reduce dust and maintain the integrity of the putty. This ensures the surface maintains its optimal bonding characteristics, allowing for a durable finish after painting or refinishing.