Defeitos e danos na pintura

501-36-22 Paint - General Information 501-36-22 DESCRIPTION AND OPERATION TO BE UPDATED LATER Repair of damage: ‡ Sand, fill with polyester or epoxide filler and re-paint. Crack formation Cracks of different lengths and depths running in all directions. Cause/damage pattern: ‡ Layers too thick. ‡ Painted several times. ‡ Temperature fluctuations. ‡ Mechanical effects e.g. distortions. ‡ Substrate not thoroughly hardened. ‡ Old paint not completely dried out. ‡ No or insufficient hardener added. ‡ 2-component materials used on nitro or TPA. TO BE UPDATED LATER Repair of damage: ‡ Sand away layers until sound substrate is reached and create new paint finish (prime, fill, apply topcoat). Shrinking back/zone edge marks Lifting or dropping in of edge zones (edges which accentuate themselves in the top coat), flow problems and loss of shine in top coat. Cause/damage pattern: ‡ Old paintwork not rubbed down to a seamless transition. ‡ Stopper and filler on a viscoplastic base primer. ‡ Filler sanded and overpainted when not thoroughly hard. ‡ Previous materials overworked too early, substrate not sufficiently hardened. ‡ Primer applied in layers which were too thick, and not dried for long enough. ‡ Sanding paper too coarse. ‡ Top coat thinned too much. TO BE UPDATED LATER Repair of damage: ‡ After hardening off the top coat, fine sand the surface and polish up, apply filler if necessary and paint once more. Blistering Small, spot-like, air-filled or water-filled blister shaped high-spots in the paint construction. Their dimensions can range from pin-head to pin-point size in a closed paint film. Arrangement and accumulation very variable. In the advanced stages, circular flaking of the paint from the substrate. These are neither boils nor corrosion. Cause/damage pattern: ‡ Moisture absorption by substrate. ‡ Insufficient drying of the substrate after wet sanding (especially on polyester material). ‡ Humidity too high before painting; condensation formation because of temperature fluctuations. ‡ Pores/sink holes in substrate not sanded out.