FAQ

The splitting of a dry paint film through at least one coat as a result of aging, which ultimately will lead to complete failure of the paint. In its early stages, the problem appears as hairline cracks; in its later stages, flaking occurs.

Possible Causes:

• Use of lower quality paint that has inadequate adhesion and flexibility. Over thinning or overspreading the paint.
• Inadequate surface preparation or applying the paint to bare wood without first applying a primer. Excessive hardening and embrittlement of alkyd paint as the paint job ages.

Solution:

• Remove loose and flaking paint with a scraper or wire brush, sanding the surface and feathering the edges. If the flaking occurs in multiple layers of paint, use of a filler may be necessary. Prime bare wood areas before repainting. Use of a top quality primer and top coat should prevent a recurrence of the problem.

Downward “drooping” movement of the paint film immediately after application, resulting in an uneven coating.

Possible Causes:

• Application of a heavy coat of paint.
• Application in excessively humid and/or cool conditions.
• Application of over thinned paint.
• Airless spraying with the gun too close to the substrate being painted.

Solution:

• If the paint is still wet, immediately brush out or re-roll to redistribute the excess evenly. If the paint has dried, sand, and reapply a new coat of top quality paint. Correct any unfavorable conditions: Do not thin the paint; avoid cool or humid conditions; sand glossy surfaces. Paint should be applied at its recommended spread rate; avoid “heaping on” the paint. Two coats of paint at the recommended spread rate are better than one heavy coat, which can also lead to sagging. Consider removing doors to paint them supported horizontally.

Concentration of water-soluble ingredients on the surface of a latex paint, typically on a ceiling surface in rooms that have high humidity (e.g., shower, bathroom, kitchen); may be evident as tan or brown spots or areas, and can sometimes be glossy, soapy or sticky.

Possible Causes:

• All latex paint formulas will exhibit this tendency to some extent if applied in areas that become humid (bathrooms, for example), especially in ceiling areas.

Solution:

• Wash the affected area with soap and water, and rinse. Problem may occur once or twice again before leachable material is completely removed. When paint is applied in a bathroom, it is helpful to have it dry thoroughly before using the shower. Remove all staining before repainting.

A rough, crinkled paint surface, which occurs when uncured paint forms a “skin.”

Possible Causes:

• Paint applied too thickly (more likely when using alkyd or oil-based paints).
• Painting during extremely hot weather or cool damp weather, which causes the paint film to dry faster on top than on the bottom.
• Exposing uncured paint to high humidity levels.
• Painting over a contaminated surface (e.g., dirt or wax).

Solution:

• Scrape or sand substrate to remove wrinkled coating. If using a primer, allow it to dry completely before applying top coat. Repaint (avoiding temperature/humidity extremes), applying an even coat of top quality interior paint.

Development of a yellow cast in aging paint; most noticeable in the dried films of white paints or clear varnishes.

Possible Causes:

• Oxidation of alkyd or oil-based paint or varnish.
• Heat from stoves, radiators and heating ducts.
• Lack of light (e.g., behind pictures or appliances, inside closets, etc.).

Solution:

• Top quality latex paints do not tend to yellow, nor does non-yellowing varnish. Alkyd paints, because of their curing mechanism, do tend to yellow, particularly in areas that are protected from sunlight.

Bubbles resulting from localized loss of adhesion and lifting of the paint film from the underlying surface.

Possible Causes:

• Painting a warm surface in direct sunlight.
• Application of oil-based or alkyd paint over a damp or wet surface.
• Moisture escaping through the exterior walls (less likely with latex paint than with oil-based or alkyd paint).
• Exposure of latex paint film to dew, high humidity or rain shortly after paint has dried, especially if there was inadequate surface preparation.

Solution:

• If blisters go down to the substrate: try to remove the source of moisture. Repair loose caulking; consider installing vents or exhaust fans. Remove blisters (see Below).
• If blisters do not go all the way down to the substrate: remove them by scraping, then sanding, prime bare wood and repaint with a quality latex exterior pain

Formation of fine powder on the surface of the paint film during weathering which can cause color fading. Although some degree of chalking is a normal, desirable way for a paint film to wear, excessive film erosion can result from heavy chalking.

Possible Causes:

• Use of a low-grade, highly pigmented paint.
• Use of an interior paint for an outdoor application.

Solution:

• First, remove as much of the chalk residue as possible, scrubbing with a stiff bristle brush (or wire brush on masonry) and then rinse thoroughly; or use power washing equipment. Check for any remaining chalk by running a hand over the surface after it dries. If noticeable chalk is still present, apply a quality oil-based or acrylic latex primer (or comparable sealer for masonry), then repaint with a quality exterior coating; if little or no chalk remains and the old paint is sound, no priming is necessary.

The splitting of a dry paint film through at least one coat, which will lead to complete failure of the paint. Early on, the problem appears as hairline cracks; later, flaking of paint chips occurs.

Possible Causes:

• Use of a lower quality that has inadequate adhesion and flexibility.
• Overthinning the paint or spreading it too thin. Poor surface preparation, especially when the paint is applied to bare wood without priming.
• Painting under cool or windy conditions that make latex paint dry too fast.

Solution:

• It may be possible to correct cracking that does not go down to the substrate by removing the loose or flaking paint with a scraper or wire brush, sanding to feather the edges, priming any bare spots and repainting.
• If the cracking goes down to the substrate remove all of the paint by scraping, sanding and/or use of a heat gun; then prime and repaint with a quality exterior latex paint

Crusty, white salt deposits, leached from mortar or masonry as water passes through it.

Possible Causes:

• Failure to adequately prepare surface by removing all previous efflorescence.
• Excess moisture escaping through the exterior masonry walls from behind.

Solution:

• If excess moisture is the cause, eliminate the source by repairing the roof, cleaning out gutters and downspouts, and sealing any cracks in the masonry with a high quality, water-based all-acrylic or siliconized acrylic caulk. If moist air is originating inside the building, consider installing vents or exhaust fans, especially in kitchen, bathroom and laundry areas. Remove the efflorescence and all other loose material with a wire brush, power brush or power washer; then thoroughly rinse the surface. Apply a quality water-based or solvent-based masonry sealer or primer, and allow it to dry completely; then apply a coat of top quality exterior house paint, masonry paint or elastomeric wall coating.

Loss of paint due to poor adhesion. Where there is a primer and top coat, or multiple coats of paint, peeling may involve some or all coats.

Possible Causes:

• Seepage of moisture through uncaulked joints, worn caulk or leaks in roof or walls.
• Excess moisture escaping through the exterior walls (more likely if paint is oil-based).
• Inadequate surface preparation.
• Use of lower quality paint.
• Applying an oil-based paint over a wet surface.
• Earlier blistering of paint (see Blistering).

Solution:

• Try to identify and eliminate source of moisture. Prepare surface by removing all loose paint with scraper or stiff wire brush, sand rough edges, and apply appropriate primer. Repaint with a top quality acrylic latex exterior paint for best adhesion and water resistance.

Brownish or tan discoloration on the paint surface due to migration of tannins from the substrate through the paint film. Typically occurs on “staining woods,” such as redwood, cedar and mahogany, or over painted knots in certain other wood species.

Possible Causes:

• Failure to adequately prime and seal the surface before applying the paint.
• Use of a primer that is not sufficiently stain-resistant.
• Excess moisture escaping through the exterior walls, which can carry the stain to the paint surface.

Solution:

• Correct any possible sources of excess moisture (see Efflorescence and Mottling). After thoroughly cleaning the surface, apply a high quality stain- resistant oil-based or acrylic latex primer. Oil-based stain-resistant primers are the best type to use on severely staining boards. In extreme cases, a second coat of primer can be applied after the first has died thoroughly. Finish with a top quality latex paint.

A rough, crinkled paint surface occurring when paint forms a “skin.”

Possible Causes:

• Paint applied too thickly (more likely when using alkyd or oil-based paints).
• Painting a hot surface or in very hot weather.
• Exposure of uncured paint to rain, dew, fog or high humidity levels.
• Applying top coat of paint to insufficiently dried first coat. ¥ Painting over contaminated surface (e.g., dirt or wax).

Solution:

• Scrape or sand substrate to remove wrinkled coating. Repaint, applying an even coat of top quality exterior paint. Make sure the first coat or primer is dry before applying the top coat. Apply paints at the manufacturer’s recommended spread rate (two coats at the recommended spread rate are better than one thick coat). When painting during extremely hot, cool or damp weather, allow extra time for the paint to dry completely.