Painting up a storm this season? Check out our top tips for a stress-free session – because hey, who doesn’t want to make life easier?
Interior paint problems.... and solutions!
Problem: Blocking
Is your door sticking to the jamb? Blocking occurs when painted surfaces stick together when they’re pressed together.
Possible cause: Blocking can happen if you haven’t allowed sufficient dry time for the coating before closing doors or windows. It can also occur from using low quality semi-gloss or gloss paints.
Solution: Use a premium semi-gloss or gloss acrylic enamel paint. Low quality semi gloss and water-based paints can have poor block resistance, especially in warm, damp conditions. Follow paint label instructions regarding dry times and keep in mind that acrylic enamel paints have better early block resistance than vinyl latex paints, or solvent-based enamel paints. Try applying talcum powder too – it can relieve persistent blocking!
Problem: Cracking/Flaking/Peeling
This is 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 and/or peeling occurs.
Possible Cause: Use of a lower quality paint that has inadequate adhesion and flexibility can lead to cracking. Alternatively, over thinning, or overspreading your paint can also have the same effect. Inadequate surface preparation such as not applying a sealer or primer on porous surfaces prior to top coating, can also create cracking, flaking or peeling.
Solution: Remove all loose and flaking paint with a scraper or wire brush, sand the surface and feather the edges. If the flaking occurs in multiple layers of paint, try using a filler. Prime bare timber areas before repainting and use a premium quality primer and topcoat to prevent the problem coming back!
Problem: Mould
Black, grey or brown spots on the painted surface – yep, you guessed it, you’ve got mould!
Possible cause: Mould forms most often on areas that tend to be damp, or receive little or no direct sunlight (e.g. bathrooms, kitchens and laundry rooms). It can also form after use of flat or matt paints in areas that are likely to be subjected to moisture, or if you forget to prime a bare wood surface before applying the paint. Lastly, mould can occur if you’ve painted over a substrate or coating on which the mildew hasn’t already been removed.
Solution: Test for mildew by applying a few drops of household bleach to the area; if it is bleached away, the discolouration is probably mildew. Remove all mildew from the surface by scrubbing with a diluted household bleach solution (one part bleach, three parts water), while wearing rubber gloves and eye protection. Rinse thoroughly. To protect against mildew, use a premium quality water-based paint, and clean when necessary with bleach/ detergent solution.
Problem: Poor Flow/Levelling
Failure of paint to dry to a smooth film, resulting in unsightly brush and roller marks after the paint dries is what is commonly referred to as ‘poor flow’ or ‘levelling’.
Possible cause: Low quality paint can create poor flow, as can the application of additional paint to touch up partially dried painted areas. If you’re re-brushing or re-rolling partially dried painted areas this can also lead to poor flow or levelling. Using the wrong type of roller cover or a poor quality brush are also no-no’s!
Solution: Use premium quality water-based paints, which are generally formulated with ingredients that enhance paint flow. Brush and roller marks therefore tend to 'flow out' and form a smooth film. When using a roller, be sure to use a cover with the recommended nap length for the type of paint being used. Use of a high quality brush is important; a poor brush can result in bad flow and levelling.
Problem: Poor Hiding
Being driven crazy by old surfaces poking through your fresh coat of paint? Poor hiding is a result your dried paint failing to obscure or 'hide' the surface to which it is applied!
Possible cause: Low quality paint / tools or the wrong roller cover are all factors which can create poor hiding. An inaccurate combination of tinting base and tinting colour can also create problems, as well as using a paint that is much lighter in colour than the substrate, or that primarily contains low-hiding organic pigments.
Solution: If your substrate is significantly darker or is a patterned wallpaper, it should be primed before applying a top coat. Use premium quality paint for better hiding and flow. Use quality tools; use the recommended roller nap, if rolling. Follow manufacturer's recommendation on spread rate; if using tinted paint, use the correct tinting base. And where a low-hiding organic colour must be used, apply a primer first.
Problem: Sagging
Paint film more droopy than your downward dog at yoga? This downward "drooping" movement of the paint film immediately after application creates an uneven coating known as ‘sagging’.
Possible cause: Sagging can be caused by an application of a heavy coat of paint; application in excessively humid and/or cool conditions; application of over-thinned paint or even 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 unfavourable 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.
Top tip: Try using a product such as Dulux 1 Step for your primer, sealer and undercoat. It’s an all-in-one interior/exterior preparation coat with fantastic hiding power and good sandability, plus it’s quick and easy to apply. The fact these products offer a primer, sealer and undercoat in one also means you save time and money, while achieving a the best possible paint finish for your home.
Exterior paint problems... and solutions!
Problem: Alligatoring
Alligator skin isn’t just something us humans need to worry about during the winter months! That patterned cracking in the surface of the paint film resembling the regular scales of an alligator is what’s known as ‘alligatoring’.
Possible cause: Application of an extremely hard, rigid coating, such as a solvent-based enamel, over a more flexible coating, like a water-based primer, can cause alligatoring. Similarly, application of a topcoat before the undercoat is dry can also cause this problem. Plus the natural ageing of oil-based paints that occurs as temperatures fluctuate throughout the seasons can cause constant expansion and contraction, resulting in a loss of paint film elasticity.
Solution: Old paint should be completely removed by scraping and sanding the surface; a heat gun can be used to speed work on large surfaces, but take care to avoid igniting the paint or substrate! The surface should be primed with a high quality water-based primer then painted with a top quality exterior water-based paint.
Problem: Blistering
Blistering is the bubbles that result from a loss of adhesion and lifting of the paint film for its underlying surface.
Possible cause: Painting a warm surface in direct sunlight, or application of oil-based or alkyd paint over a damp or wet surface can both cause blistering. Exposure of latex paint film to dew, high humidity or rain shortly after paint has dried, especially if there was inadequate surface preparation, can also create blistering.
Solution: If blisters go down to the substrate, first try to remove the source of moisture. Remove blisters by scraping, then sanding the surface. Prime any bare timber with a high quality water-based primer, and repaint with a high quality water-based exterior paint.
Problem: Dirt Pickup
Devastated to see your lovely new paint job accumulate dirt, dust particles and other debris?
Possible cause: Use of a low quality paint, oil splashing onto the substrate or air pollution such as car exhaust and flying dust can all collect on the body of your home and its horizontal trim, leading to dirt pickup and a mildew-like appearance.
Solution: Wash off all surface dirt before priming and painting. Clean off dirt with a scrubbing brush and detergent solution, followed by a thorough rinsing with a garden hose. (Heavier dirt accumulations may require the use of a power washer.) While dirt pickup can't be eliminated entirely, top quality exterior latex paints typically offer excellent dirt pickup resistance and washability. Also, higher gloss paints are more resistant to dirt pickup than flat paints, which are more porous and can more easily entrap dirt.
Problem: Fading/Poor Colour Retention
Surfaces that are exposed to the sun are more likely to show premature and/or excessive lightening of paint color. Fading/poor colour retention can also be a result of chalking of the coating.
Possible cause: Use of an interior grade of paint for an outdoor application can create fading or poor colour retention. Using a lower quality paint can also lead to rapid degradation (chalking) of the paint film, as can using a paint colour that is particularly vulnerable to UV radiation, such as bright reds, blues and yellows.
Solution: When fading/poor color retention is a result of chalking, it is necessary to remove as much of the chalk as possible. If you’re repainting, make sure you use a quality exterior house paint in colours recommended for exterior use.
Problem: Lapping
Got a split personality? Appearance of a denser colour or higher gloss where wet and dry layers overlap during paint application is what’s also known as ‘lapping’.
Possible cause: Failure to maintain a 'wet edge' when applying paint.
Solution: Maintain a wet edge when painting by applying paint toward the unpainted area and then back into the just-painted surface. This technique (brushing from "wet to dry," rather than vice versa) will help produce a smooth, uniform appearance. It is also a good idea to minimise the area being painted and plan for interruptions at a natural break, such as a window, door or corner (especially important when applying stain to bare wood). Tip: Solvent-based paints generally have superior wet edge properties.
Problem: Wrinkling
Wrinkling is demonstrated by a rough, crinkled paint surface that occurs when the paint forms a ‘skin’.
Possible cause: You may have applied the paint applied too thickly (more likely when using solvent-based paints), or perhaps painted a hot surface or in very hot weather. Exposure of uncured paint to rain, dew, fog or high humidity levels can cause wrinkling too, as can painting over a contaminated surface such as dirt or wax. Applying the topcoat to insufficiently dried first coat is also a no-no.
Solution: Scrape or sand substrate to remove wrinkled coating. Repaint; applying an even coat of high quality exterior paint. Make sure the first coat or primer is dry before applying the topcoat. 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 humid, cool or damp weather, allow extra time for the paint to dry completely. Check out www.dulux.co.nz for more information about products that can solve your paint problems – and create paint perfection!
