- Home Improvement
How to Solve House Painting Problems
Generally speaking, any change in the appearance or integrity of a paint film is a potential problem. Many things can happen to cause a change, but perhaps the most prevalent and offensive is the loss of adhesion. This distressing phenomenon can have a variety of causes, but the most common is, water. When water penetrates through paint to the wood underneath the bond which holds the paint is damaged. The next section outlines symptoms , causes and solutions of paint failure and other common problems that should be addressed if they occur.
Problem: Soluble stains from knots, oil, grease, dies, redwood , cedar or water are present on the substrate and show through the finish coat.
Cure: Seal the surface with shellac, aluminum paint or special stain sealer. If the stain is soluble in water, use an oil type finish . If soluble in solvent, use a water based paint. Do not use water based paint over shellac.
Problem: Paint film becomes gritty or rough. Small to large blisters appear, usually caused by trapped solvent, moisture or because the paint was applied in direct sunlight.
Cure: Scrape off blisters, feather and sand the effected areas, spot prime and then apply another coat of paint. Make sure the substrate is dry and not in direct sunlight. If this occurs in Latex paint, scrape, wire brush and/or sandblast to remove all paint. Prime and repaint.
Problem: The paint film is gritty or rough , hollow blisters or fish-eyes appear due to the surface not being properly primed or sealed. Another cause could be that the paint was "dry rolled" too much or that the wrong roller was used.
Cure: Make sure the proper equipment is selected, including roller type, nap length, etc. Lightly sand the surface and apply an additional coat of finish. If bubbling continues with latex enamels , add one to two ounces of mineral spirits per gallon.
Problem: There is a powdery effect or substance on the paint film brought about through the breakdown and releasing of pigment particles. Desirable in moderation on white surfaces since, during washing or rain, the chalk carries off the dirt. It is undesirable when it runs down and over brick or other colors.
Cure: Wipe off excessive chalk and recoat with a non-chalking paint. Use a surface conditioner if latex is being used . To remove chalk from brick and other surfaces, scrub with a strong detergent. The discoloration will weather away eventually, if the cause has been removed.
Color Streaking/Blotching & Framing
Problem: Dark and light color streaks or blotches appear due to excess color or the paint not being mixed long enough.
Cure: Remix the color in a proper base and repaint. Allow longer mixing time .
Cracking, Flaking, Peeling
Problem: Cracks across wood grain, with their edge curled away from the cracks. Similar to Alligatoring, this condition is caused by too many coats of paint. When the heavy paint film is built up by repeated paintings, the thick film will no longer expand and contract with the wood. Also can be caused by rapid moisture content of the wood or, if the paint has weathered too long.
Cure: Remove all cracked and peeling paint by scraping, burning, sanding or with paint removers. Repaint using only enough to restore appearance. To prevent future cracking, wash the dirt off occasionally instead of painting . If painting is necessary and areas have not weathered sufficiently, sand thoroughly to reduce film thickness and improve adhesion .
Low or Uneven Gloss
Problem: The sheen or gloss of the film appears lower than normal, is uneven or mottled, usually due to the surface not being properly sealed or primed. Other causes include the paint not being properl y mixed or the exterior finish being applied late in the evening when dew condensation begins.
Cure: When the surface is dry, apply another coat of paint. You might want to sand the surface lightly first to make sure there is proper adhesion.
Problem: A fungus caused discoloration that appears like a dirty film with a green or black splotchy look. In most cases a combination of moisture, low light and inadequate ventilation provides the environment which encourages growth of fungus. Cure: Scrub vigorously with a mildew remover such as trisodium phosphate , or with a solution of household bleach, detergent and water. When completely dry, repaint with a coating to which a fungicide has been added.
Problem: Peeling to Bare Base: Paint film is coming off of the surface in sizeable chips, leaving bare wood. This is usually preceded by blistering, caused by water in the wood. This problem is frequently concentrated around windows, outside kitchens, bathrooms and near the ground where moisture is present.
Peeling Between Coats : This is generally caused by poor adhesion due to a smooth, glossy or chalky surface.
Cure: For peeling to bare base; locate the moisture source and vent to allow moisture to escape. Seal untreated edges and caulk around flashing, eaves, etc. to keep moisture out. Scrape, sand, spot prime and finish the areas with a high quality paint.
Fore peeling between coats; remove any loose paint, sand to roughen the surface and feather out edges, then repaint. For chalky conditions, remove loose paint and treat with a surface conditioner to bind the chalk, then repaint.
Poor Hide or Coverage
Problem: An old finish is showing through the paint film, or there are multiple coats of paint and the substrate still shows through . Generally this is due to not enough paint being applied or excessive thinning or poor quality of the coating.
Cure: Apply another coat of un-thinned product using the proper tools.
Ropiness, Heavy Roller Stipple
Problem: There are prominent roller or brush marks and the paint film is not smooth. The paint may have been applied too thin , rolled excessively or the surface might not have been prepared properly . Other causes include high surface temperature, poor quality tools and the previous coat not being dry enough before applying the finish paint.
Cure: Sand to remove brush or roller marks, and then repaint using proper tools and with proper preparation .
Problem: Paint film sags looking like curtains hanging on a window, or tear drops. This happens when paint is applied too heavily or has been thinned but not evenly applied.
Cure: When the paint is dry, sand out all sags and runs, Then apply another coat properly .
Slow or Poor Dry
Problem: The paint film is tacky or soft beyond the normal dry time. Could be a result of grease, wax , moisture, cold temperatures or high humidity as well as an improperly cleaned surface.
Cure: If the paint won't dry, remove completely and start over after properly preparing the substrate .
Problem: This is when the paint film is raised up in wrinkles but not broken . Caused by paint film drying rapidly on the surface but slower underneath, due to painting in the sun or during low temperatures. Wrinkling can also be caused by applying hard over soft paint.
Cure: Remove the wrinkled paint film by sanding or with paint remover. Repaint under favorable conditions using the proper materials. Avoid painting in hot, direct sun. If close attention is paid to the three "enemies" of paint; Water (moisture), sunlight and temperature, and the proper procedures are implemented for preparing the substrate, most problems can be avoided .