Before sanding, be sure the surface is clean and well degreased. Most dirt can be removed with water and ammonia.
Surfaces to be degreased:
Existing paint layers - Epifanes Spraythinner for P & V.
Bare wood - Epifanes Spraythinner for P & V.
Tropical bare wood - Epifanes Spraythinner for P & V.
Bare steel - Epifanes Epoxythinner D601
Aluminum - Epifanes Spraythinner for P & V.
Fiberglass - Epifanes Fiberglass Prep Cleaner
Thorough sanding is required to ensure optimum adhesion between coats to create a smooth undercoat. Unless instructed differently, sand every coat or finish before applying a new coat.
Each surface requires a particular type and grit of sandpaper. Bare surfaces, primers, undercoats and fillers need to be dry sanded in order to avoid the intake of moisture. Sanding between topcoats can best be executed with a fine grit wet sandpaper and water. One should avoid visible sanding scratches in the topcoat. When (dry) sanding, we recommend wearing an appropriate dust mask to avoid breathing fine dust particles. When sanding products containing lead or chromate, it is imperative that one wear an appropriate breathing apparatus. The recommended type of sandpaper and grit are determined in each system.
An important consideration when (re) painting existing, unknown surfaces, is the choice of the correct product. In general, when a surface has been previously painted there are two possibilities. Either a one-component paint system or a two-component paint system has been applied. By placing a cloth saturated with Epifanes Fiberglass Prep Cleaner for 15 minutes on the surface to be painted, the difference will become evident. If the Fiberglass Prep Cleaner acts a paint remover and begins to wrinkle the paint, it is a one-component paint. If the paint remains intact, you are most definitely dealing with a two-component paint product. In principle, a one-component paint may be applied to a well cleaned and sanded (320 grit wet or dry abrasive paper) two-component paint coat. The bond is acquired mechanically by roughing the surface. A two-component product however, may not be applied over a one-component paint coat, as the solvents of the two-component product will act as a paint remover on the one-component coat.
The paint does not dry thoroughly:
The temperature is too cool for good flow, there is not enough air circulation, or too thick a layer has been applied. Applying too thick a coat may entrap solvents in the paint. Drying problems can also occur by applying a one-component product directly onto a "too fresh" epoxy or fiberglass coat. The required amount of time for thorough drying depends on the amount of solvents remaining in the original coat. In some cases thorough drying may not occur at all. These coats must be removed.
The coat has developed wrinkles:
Wrinkling of paint coats can be caused by the application of too thick a layer (often on horizontal surfaces), applying a fresh coat on a surface not yet thoroughly dry, or application in direct sunlight. The entrapped solvents may, in time, evaporate through the original layer of paint. If necessary, this can be encouraged by lightly sanding the wrinkled surface, letting air into the paint layer allowing it to dry. When the paint has dried, sand to a fresh surface and recoat.
Blisters form during application:
This is caused by application onto a hot surface or by moving the finished piece into direct sunlight after application.
Blisters form after application:
This is generally caused by the expansion of moisture or entrapped solvent under the finish.
The paint refuses to flow in a continuous uniform coating. This is caused by the presence of water, grease, wax, silicones or other contamination on the surface, low temperature, or application of paint on a surface that has not been sanded or sanded insufficiently. In all cases, remove the paint while still wet. Clean the surface with an appropriate cleaner and degreaser. Sand thoroughly. Recoat.
Pulling during application:
There is sometimes a pull as the paint is being applied, when insufficient material is being carried in the brush or when the paint is too thick for ambient conditions. This is usually overcome by carring more material in the brush or by further thinning of the paint.