Surface preparation
Applying the thermoplastic coating to the surface is a multi-day process. The pool must be clean and dry to apply the epoxies before installation can commence. To do this, the pool must be drained and the surface etched or profiled (when necessary), then cleaned with a pressure washer or trisodium phosphate (TSP), and allowed to dry overnight. Then, all fixtures must be covered or removed to avoid contact with the thermal epoxy. The hydrostatic plug at the bottom of the pool should also be removed to stabilize groundwater.
The application process is safe when the installer is trained, has a full understanding of the proper safety practices, understands the equipment, and follows all recommended procedures. Pool professionals already have the knowledge required to properly assess the condition of pool surfaces. The surface or substrate of the pool or spa should be made as smooth as possible, prior to application, to avoid any imperfections showing through the finish. Thermoplastic spray finishes will cover spider cracks and minor pool blemishes; however, if the pool shows signs of severe deterioration or etching, preparation must be performed prior to application to avoid noticeable imperfections. If not prepared properly, extensive labour will be required during the install. Therefore, it is much easier and more cost effective to repair the surface first than to try and fill any voids with thermoplastic later.
The installation timeline for a thermoplastic pool finish, for an average size pool, is approximately three days from start to finish:
Day one
On the first day, the main focus is preparing the substrate surface followed by masking. Once the substrate is determined to be sound, repaired, and readied for the thermoplastic application, the next step is to mask all of the surfaces where the finish must be avoided.
For example, all tiles, copings, light fixtures, drains, fittings, and anything that will not be coated with the thermoplastics material should be masked. A specialized heat-resistant tape (used to define a line between the tiles and the pool surface) and fabric (secured with the tape to cover tile lines and copings) specifically designed for use with a thermoplastic-spray system should be used. The fabric can be used continuously throughout the season—from application to application—the tape is single use only, however.
Do not mask the entire pool surface area, steps and, if applicable, slides and/or diving boards, etc. When applying a new finish on an existing pool or spa, it is best to remove the old fittings and replace them with new ones. Thermoplastic overspray is minimal because the settings can be set for the most economical method of application.
The epoxy used for pool finishes is a two-component, solvent-free epoxy resin, which is specifically designed for use on concrete and similar substrates. When installed, epoxy provides an ideal surface for the thermoplastic coating to bind.
Day two
After the application of epoxy is applied, the first pass of thermoplastic is made as the epoxy starts to become tacky. This first pass is referred to as a ‘hot flock’—the first minimal coat of thermoplastic powder applied lightly over the surface. This action embeds the thermoplastic into the epoxy to form a permanent mechanical bond coat.
