Paints & varnishes

The substrate determines the appropriate system: GRP/gelcoat requires an adhesion primer or epoxy barrier coat depending on its condition; aluminum requires special, aluminum-compatible primers (corrosion protection); steel requires rust protection/2-component epoxy; wood requires suitable wood primers and flexible systems. For existing coatings, the most important question is: What type of coating is already on the surface (1K/2K, antifouling type)? If in doubt, test or sand first and apply according to the manufacturer’s instructions.

A proper system build-up usually follows this principle: Prepare the substrate → Primer/adhesive primer (depending on the material) → Optional barrier coat (osmosis protection/moisture barrier) → Topcoat (above water) or antifouling (below water). Which step is necessary depends on the material, the extent of damage, and the desired protection. It is particularly important to adhere strictly to the recoating intervals.

Success = Preparation + Film Thickness + Timing. Remove wax/salt/oil, sand according to specifications, and dust and degrease the surface. Apply the coating at the recommended wet/dry film thickness and observe drying times and recoating windows. Pay attention to the dew point (no condensation) and avoid application when humidity is too high or temperatures are too low.

Only if the manufacturer expressly approves it. Without approval, there is a risk of adhesion problems, reactions (swelling/dissolution), or premature peeling. This applies particularly to 1K/2K combinations and antifouling (hard/self-polishing). If you are unsure, either choose a tested compatibility/adhesion primer or stick to a single manufacturer’s system.

Common mistakes include: insufficient degreasing, incorrect grit size, application under unfavorable humidity/temperature conditions, incorrect dilution, coats that are too thick or too thin, and missing the recoating window. Use the data sheet as a work instruction, work in stages, and document the number of coats and date—this will help during the next refit.

Store in a cool, dry, frost-free place and keep tightly sealed. Close containers immediately after use to prevent solvent loss. Pay attention to the shelf life and safety data sheet. Store two-component products separately and mix only as much as can be used within the pot life. Dispose of leftover quantities and cleaners in an environmentally responsible manner.