Proper surface preparation is the key to a long lasting paint job for both residential and commercial/industrial applications. This is true regardless of the types of paints or coatings that are used.
Although there are many important aspects of applying paint such as proper temperature, film thickness and dry time, none are more important than proper surface preparation. In fact inadequate surface preparation is the leading cause of coating failure. While expenses are involved in properly preparing a surface, the consequences of improper preparation can far exceed the entire cost of your paint project.
One example that comes to mind is when a plant manager called us in to look at a roof and bar joist ceiling. The ceiling was approximately 125,000 square feet and had been coated three years earlier. The ceiling was a nightmare as over 50% of the area had visible peeling. The company had spent $80,000 on the project only to have to pay for it to be removed and then recoated. The total cost now with the rework project now exceeded $200,000.00. The reason that the coating was peeling was that the surface was not washed prior to coating. The cost for cleaning would have been less than $20,000.00.
Obviously the company made a poor decision when choosing not to have the Rust Paint ceiling cleaned. One wonders why a contractor even gave them that option, or if the painting contractor adequately warned them of the consequences of not cleaning.
A good painting contractor understands the importance of surface preparation and what it takes to insure a quality job. They would also make sure that their client fully understands what the prep work is, and how critical it is to assure a quality job. Some painting contractors will often offer an upgraded paint job, generally consisting of added prep work, for an additional cost. Other companies have that cost built in to their quote knowing that necessary preparation will be the key to a quality job.
There are a number of methods for surface preparation; the best method will depend on the condition of the surface:
- Dirt build up: Hand wash or power wash.
- Glossy surface: Light sanding creates a profile for good adhesion.
- Oil on surface: A mild degreaser or tri-sodium phosphate.
- Loose debris, rust paint etc: Sand blasting scraping and/or hand tool cleaning.
After you have prepared the surface it is a good idea to do a simple adhesion test before painting the entire surface. After preparing the surface, coat a small area and let dry. When the paint is dry you can scribe cross-hatches using a utility knife or razor blade. Then apply an adhesive tape over the cross-hatching and remove. If the coating stays on the surface, you have good adhesion.
Whether you plan on hiring a contractor for your next paint project or doing it yourself, understanding how good surface preparation assures a quality paint job could be the key to a long lasting finish