Description::: Uneven surface formation - much like that of the skin of an orange - which results from poor coalescence of atomized paint droplets. Paint droplets dry before they can flow out and level smoothly together. Origin and Potential Causes::: Improper gun adjustment and techniques. Too little air pressure, wide fan patterns or spraying at excessive gun distances causes droplets to become too dry during their travel time to the work surface and they remain as formed by gun nozzle. Extreme shop temperature. When air temperature is too high, droplets lose more solvent and dry out before they can flow and level properly. Improper dry. Gun fanning before paint droplets have a chance to flow together will cause orange peel. Improper flash or recoat time between coats. If first coats of enamel are allowed to become too dry, solvent in the paint droplets of following coats will be absorbed into the first coat before proper flow is achieved. Wrong thinner or reducer. Under-diluted paint or paint thinned with fast evaporating thinners or reducers causes the atomized droplets to become too dry before reaching the surface. Too high viscosity. Low shop temperature. Too little thinner or reducer. Materials not uniformly mixed. Many finishes are formulated with components that aid coalescence. If these are not properly mixed, orange peel will result. Substrate not sanded thoroughly Prevention Techniques::: Use proper gun adjustments, techniques, and air pressure. Schedule painting to avoid temperature and humidity extremes. Select the thinner or reducer that is suitable for existing conditions. The use of a slower evaporating thinner or reducer will overcome this. Allow sufficient flash and dry time. Do not dry by fanning. Allow proper drying time for undercoats and topcoats. Not too long or not too short. Reduce to recommended viscosity with proper thinner/reducer. Stir all pigmented undercoats and topcoats thoroughly. Prepare and sand substrate correctly. Follow recommendations on technical data sheets. Remedy::: For mild cases, sand and polish using recommended materials and techniques. In extreme cases, sand down to smooth surface and refinish, using a slower evaporating thinner or reducer at the correct air pressure.
Description::: Bubbles or pimples appearing in the topcoat film, application Origin and Potential Causes: Residue of sanding water in corners, edges, crevices, or below decorative strips. Ambient humidity too high. Improper surface cleaning or preparation. Tiny specs of dirt left on the surface can act as a sponge and hold mosture. When the finish is exposed to the sun (or abrupt changes in atmospheric pressure), moisture expands and pressure builds up. If the pressure is great enough, blisters form. Wrong thinner or reducer. Use of a fast-dry thinner or reducer, especially when the material is sprayed too dry or at an excessive pressure. Air or moisture can be trapped in the film. Excessive film thickness. Insufficient drying time between coats or too heavy application of the undercoats may trap solvents which escape later and blister the color coat. Contamination of compressed air lines. Oil, water or dirt in lines. When wet sanding polyester and applying topcoat without enough time for the water to evaporate. Incompatibility of materials. Prevention Techniques::: Always remove exterior trim. Blow and dry carefully. Thoroughly clean areas to be painted before sanding. Be sure surface is completely dry before applying either undercoats or topcoats. Don't touch a cleaned area as the oils in your hands will contaminate the surface. Select the thinner or reducer most suitable for existing shop conditions. Allow proper drying time for undercoats and topcoats. Be sure to let each coat flash before applying the next. Drain and clean air pressure regulator daily to remove trapped moisture and dirt. Air compressor tank should also be drained daily. Clean substrate carefully. Remedy:::If damage is extensive and severe, paint must be removed down to undercoat or metal, depending on depth of blisters; then refinish.
Description::: A surface with this defect will show particles of different sizes deposited in the primer or color. Origin and Potential Causes::: Various types of contamination typically introduced during the application or drying process. Static charge on surface of vehicle. This condition helps the attraction of dust. Dust and dirt from dry sanding, cloths, etc. Use of poor quality masking paper. Tack rag was not used before spraying, or not immediately before. Inadequate filtration of air. Dry spray dust settling on wet paint. Paint kept in dirty containers/tins. Paint was not strained. Operators clothing bearing dirt, fibres and dust. Paint has been kept longer than recommended. Inadequate filtration of compressed air. Activator or thinner used were incorrect. The car was not thoroughly blown out. Tintings/pigments were not sufficiently stirred. Spray dust accumulated on spray booth surfaces/walls. Use, re-thinned, of 2K materials after the recommended potlife. Prevention Techniques::: Use anti-static fluid or attach the vehicle to electrical earth. Keep bodyshop as clean as possible. Always keep spray booth doors closed. Wet floor and wall if necessary. Wear special spraysuits. Blow out all mouldings, seams etc. Blow the vehicle out before placing it in the spraybooth. Use the tack rag immediately before applying each coat. Care of the maintenance of the equipment. Follow the recommendations (pressure, thinner) to avoid overspray. Clean the vehicle before starting the repair. Mix the color thoroughly after sufficient stirring of tintings. Do not exceed the recommended potlife of 2K materials. Use a fine strainer. Remedies::: Allow the finish to harden completely, fine sand and polish. If the defect is severe, sand and respray.
Description::: Blisters on the paint surface caused by trapped solvents in the topcoats or primer-surfacer, a situation which is further aggravated by force drying or uneven heating. Origin and Potential Causes::: Solvent or air trapped in film escapes during drying leaving pop marks. Incorrect spray viscosity, spray pressure, flash off time, or improper drying. Incorrect choice of hardeners and/or thinners. Use of fast-dry thinner or reducer, especially when the material is sprayed too dry or at excessive pressure. Excessive film thickness. Insufficient drying time between coats and too heavy application of the undercoats may trap solvents causing popping of the color coat as they later escape. Incorrect drying of primer / fillers. Improper surface cleaning or preparation. Infrared facilities too close. Baking was started too soon after application. Baking temperature too high. Prevention Techniques::: Thoroughly clean all areas to be painted. Select the thinner or reducer that is suitable for existing shop conditions. Don't pile on undercoats or topcoats. Allow sufficient flash and drying time. Allow each coat of primer-surfacer to flash off naturally - DO NOT FAN. Apply film at recommended thickness. Follow technical recommendations of products in use.
Description::: Heavy application of sprayed material that fails to adhere uniformly to the surface. Origin and Potential Causes::: Incorrect spray viscosity, flash off time, technique, or film thickness. Defective spray gun or incorrect gun setup. Wrong thinner or reducer. Too much thinner or reducer. Lighting in the spraybooth is not accurate and the painter is unable to apply coating correctly. Surface is contaminated by oil, grease, etc. Shop, surface or paint is too cold. Low air pressure (causing lack of atomization), holding gun too close, or making too slow a gun pass. Incorrect technique of application. Paint drops from the gun. Prevention Techniques::: Allow vehicle surface to warm up to at least room temperature before attempting to refinish. Try to maintain an appropriate shop temperature for paint areas. Use proper gun adjustment, techniques, and air pressure. Don't pile on finishes. Allow sufficient flash off and drying time in between coats. Select proper thinner/reducer. Read and carefully follow label or product data sheet instructions. Select the thinner and reducer that is suitable for existing shop conditions. Install accurate lighting systems in the spray booth. Ensure that the spray gun is in good working order. Remedy::: Wash off the affected area and let dry until you can sand the affected area to a smooth surface and refinish. For solid colors and clearcoats, sanding and polishing is recommended. In the case of a basecoat, refinishing after sanding is necessary.