With the current situation of small enterprises doing contracting works, there are many operators who can offer cheap rates to get work done. This is achieved by using inferior materials and dubious application techniques.
Paintwork is all about preparation. If the surface onto which a coating is applied is compromised, the paint will fail. Roadmarking has to be one the worst cases for this, as the roadway becomes coated with oil, grease, rubber residue and general “gunk”. This is moved around the area by the passage of tyres. Any attempt to overcoat markings will be compromised by this problem, which is fairly unique in the painting industry.
In order to remove this from the equation, the surface has to be correctly prepared. This can only be effectively done by blasting the surface clean. This has a triple effect if done on existing markings:
- It removes any undesirable residues from the surface.
- It removes any loose or poorly-bonded paint.
- It roughens the surface to give it a texture that vastly improves the “mechanical” grip of the coating (think of painting onto a sheet of 80 grit sandpaper, as opposed to a sheet of plate glass).
Once the surface has been cleaned, a proper quality paint coating can be applied as soon as possible, before any traffic (vehicle or pedestrian) can “track” the dirt from the surrounding areas over the newly-prepared surface.
The film-thickness of the coating can be tested by using thin metal “painting-plates” that the coating is sprayed onto whilst doing the application work on a regular and random basis. These plates can then be allowed to dry, then tested with an electronic “dry-film-thickness” tester, which will provide conclusive proof of correct application.
The final important step is to “defend” the new markings until fully dried. (Summer time, about 30 minutes, winter or basement about 1 hour). This is essential so that no dirt can get “tramped” into the fresh coating, causing it to look dirty.
One needs to blast new concrete surfaces before painting, to ensure the surface is “textured”, as well as to remove any curing-compound that may have been applied to power-floated floors.