Modern Day Drywall
Today’s drywall is different than it used to be. While this is not a bad thing, it does mean the process and products you’re familiar with on how to paint drywall has changed slightly. For example, most drywall today is recycled or imported. This causes a single 4 x 8 sheet of drywall to absorb differently in areas from the inconsistent materials that are used.
During the tape, mud, and sanding stage, your drywall begins to take on more of a quilt type pattern each area absorbing materials differently. The paper used on top of the drywall is less forgiving. If the installer sands the paper, little hairs will stick up. All of these irregularities can cause light coming across a painted board to look shaded. The porosity of the drywall sucks the sheen out of the paint leaving holidays or flat areas. The smoothness of the board highlights these imperfections.
Many primers and flat paints initially used on drywall are low cost, calcium carbonate or clay-based primers with little or no acrylic resin to seal up the different levels of porosity in the face paper and tape joints. The low-cost primers make the surface look prepared, but they remain porous. Using a primer that is porous will lead to unsatisfactory results for future finish coats.
How to Paint Drywall
The trend today for cost purposes is to spec a level 4 drywall finish leaving a lot of work on the painter to make the final product look acceptable. A level 4 is difficult for a contractor since they have to accept the conditions as is on the drywall. Since paint coatings are not usually more than 3 mils (3/1000th of an inch thick) it can be difficult for a painting contractor to improve the appearance of the surface they are given.
Level 4 Drywall Finishing- No marks or ridges. Ready for priming followed by wallcovering or flat paints or light textures paints.
Level 5 Drywall Finishing- An entire surface covered with O’Leary Paint Drywall resurfacing primer. Skim coat and ready to prime before using eggshell, satin or semi-gloss coatings.
What Can a Painter Do?
Create a uniformly sealed surface. That is easier than it sounds. Here are a couple suggestions on how you can achieve this.
Use a Quality Primer
Quality Acrylic Primer: You will want to use a high-quality acrylic primer like Motor City Paints V8000 primer. It is resin rich and will seal the surface when properly applied. High quality doesn’t need to be high priced, but you can expect to pay more than your traditional clay-based primers.
Dry Wall Resurfacing Primer: This is a high build primer that is used in place of skim coating to achieve a level 5 drywall finish. Drywall surfacing products are applied by airless sprayer and for best results back rolled with a dry roller.
Backroll each coat of primer or paint immediately after it is sprayed. Back rolling forces the primer and paint into the substrate to maximize the paint or primers ability to seal up the surface, making it easier to achieve the desired final dried film thickness. Back rolling will also leave a slight stippled pattern on the smooth surface that will help hide any other surface imperfections. This will allow for the painted finish to be touched up more easily when using the same size and type of roller skin.
Apply at least 2 top coats to achieve a dried film thickness over 3 mils. If the dried film is under 3 mils it will be impossible to touch up the paint. Ultimately a quality primer and 2 coats will improve durability and future touch-ups.
Other Fun Tips
Following these steps will make your future jobs run smoother. It will reduce damage caused by other trades and improve your touch-ups. This reduces your time spent on a punch list helping you stay on time and on budget.
Spray tips wear out after 75 to 100 gallons of paint. This means your spray pattern goes from a cat eye to a garden hose. Back rolling will even out a poor spray job. It will make sure the paint is distributed consistently.
Temperature and Touch-Up
Paint dries evaporation. Science class taught us molecules in water move slowly at cold temperatures and faster at high temperatures. The speed in which molecules move around while the paint is drying has an impact on color, sheen & durability. For every 5˚F drop in temperature paint actually changes color. Sometimes the color change is more noticeable than others. To improve your touch-ups make sure you are in a controlled environment. When painting outside, be sure to do touch-ups at a similar temperature as when the original coat was applied.
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