If you need to paint outside with latex paint when temperatures are moving up and down like a yo-yo, I suggest you use one of the latex like Duration, Resilience, or SuperPaint. These products can be applied and will cure at lower temperatures, as low as 35° F. Traditional latex-based paints need temperatures above 60° F to cure properly. Warmer temperatures are needed to allow the latex particles to coalesce, or melt together. That is why the spring and fall can be tricky times to paint outside. A common mistake is to paint when the daytime high temperature gets above 60° F and the nighttime temperatures get much cooler because dew forms on almost everything as soon as the sun goes down. Even though the temperature was OK at the time of application, the paint can stop coalescing. This permits moisture to get into the uncured paint film allowing certain ingredients to come to the surface when the moisture evaporates, causing surface staining and possible adhesion problems.
Ideally, the temperature should be in the suggested range and above the dew point for at least 48 hours after application. Colder temperatures and moisture on the surface will not allow a paint film to form properly. This will shorten the life expectancy of the paint and could cause surfactant leaching, mildew growth, frosting, and adhesion problems. When the forecasters predict changing temperatures that may drop below the normal recommendation of 50° F for latex paint, consider using a house paint that can be applied and will cure at temperatures as low as 35° F. This will give you the opportunity to extend your painting season by as much as two months in most areas of the country.
Spraying is faster. Brushing is neater. Many painters use a combination of the two methods by spraying to quickly get paint on the surface, followed by back brushing to spread the paint out evenly, resulting in a good looking finish. It may depend on how wide the surface is that you're painting as well. If you're painting big surfaces, cut in with a brush and roll the rest of the panel. For most siding areas, if you can't spray and backbrush, stick with a brush. Most siding areas are not wide enough to use a roller, so a good 4" brush that holds a lot of paint will work much better.
These terms refer to the waiting period required between the time you mix and the time you can start applying a two-part product, such as an epoxy. This allows the necessary chemical reactions between the two parts to begin so the coating will cure and perform properly.
Yes. You want to follow the label directions for the product you are using. Most products require at least 4 hours of dry time before moisture can settle on the surface. The cooler the temperature the sooner you should stop painting.
Until a few years ago you needed to paint above 50° F. Sherwin-Williams now has products like Duration, Resilience, SuperPaint and A-100 Exterior that will allow you to paint down to 35° F.
Rolling is usually the best method. Consult the Product Datasheet for specifications and recommendations on this. If applying by airless, you should use .021 to .031 tips because this is a fairly heavy-bodied material. When working with a low-texture material, the spray unit must be specifically designed for aggregate coatings. Generally, you can spray on 20 to 30 wet mils by cross coating (a horizontal coating pattern followed by a vertical coating pattern). When rolling, almost invariably a minimum of two coats will be needed to achieve the acquired film thickness. When applying over flat surfaces like poured-in-place concrete, simple spraying works well. When applying over rough surfaces like stucco, spraying would have to be followed by backrolling. Backrolling involves an additional pass with a wet, but not loaded roller, that will force the material into contact with all dips and holes in the surface.
Because this material goes on with a heavy film thickness, there is a tendency to roller-track. To avoid the problem, the painter should "dress down" when rolling. In other words, before redipping, always finish rolling with a downward roll. This will give the same repeat pattern throughout the job.
The key thing to consider when repainting aluminum siding is not the method of application, but the surface prep. Aluminum siding is normally painted only after it has faded and chalked. If the chalkiness is not removed, the paint will not adhere properly. Spraying will be much quicker than brushing, and as long as the proper tip size and pressure are used, it will produce excellent results. Duration, Resilience, or SuperPaint Exterior Acrylic, applied to a properly prepared surface will produce a quality long lasting finish.
Try not to paint too large of an area at one time. Overlapping occurs when a freshly painted section begins to dry before you start painting the adjoining area.