Patching Drywall Before Repainting
By Owen Whetzel
Drywall, also known as gypsum board ("gyp board"), wallboard, plasterboard, or by the brand name, USG Sheetrock ("rock), has replaced lath and plaster for walls and ceilings in homes, particularly in the west. In most cases it is fairly easy to repair. The difficult part may be matching texture on the area surrounding the repair.
Before repainting, it is always wise to first dust and then wash walls, followed by the prep work. Filling holes and cracks, and making repairs are one of the first steps to take.
Some drywall repairs can be simplified, by using a commercially available drywall patch, which will fit over a hole or dent, but here are some more conventional approaches to fixing damaged drywall.
Filling small nail holes and dents
Use a brush attachment to vacuum the spot you will be repairing and remove any loose paint. Use a quality spackling compound, to fill the holes or dents (dampen the area, if specified on the spackling compound container). Put a small amount of spackling compound on a plastic or metal putty knife, small cake-decorating knife, artist's palette knife -- even your thumb can be used for some repairs. (However, don't use anything made of aluminum, as it may make dark marks around the area you are patching.) Push the compound into the hole and smooth the surface. You only want to fill the hole or dent, not leave a gob of compound on the surface.
Use a damp cloth to wipe away excess from around the patched area.
If the filled hole is smooth and the surrounding area is textured, experiment with your tools and fingers, to match the texture. Some textures can be matched by using a sponge or brush.
Filling larger holes up to about ½-inch to ¾-inch in diameter
Vacuum the hole and then clean out the hole using a dampened cotton-tipped applicator (Q-Tip). Apply some household white glue (e.g., Elmer's Glue-All) to the inside of the hole and to a small piece of paper towel. Roll the glue soaked paper towel into a ball and carefully stuff it into the hole. Make certain, that it fits securely and sits about 1/16-inch below the surface of the surface. Allow the plug to dry. Fill in the remaining surface area to match the wall, using a high quality spackling compound, as described above (This method is excellent for repairing holes left, when hollow wall anchors, also commonly known as a "Molly bolt," are removed).
Filling large dents
Remove any loose paint.
Sand the damaged area and about 1/2-inch surrounding it, using coarse sandpaper. This will give the area tooth, so that spackling or joint compound adheres better.
Use a brush attachment, to vacuum dust from the dent and then wipe the area, to be patched with a damp cloth.
Use a 3-inch or wider wide-bladed putty knife, to apply spackling or joint compound. Do not apply it thicker than specified on the product container. With repairs of deep dents, 1/4-inch or more, it is best to patch in 1/4-inch layers and allow each layer to dry overnight. Sand between each application with coarse sandpaper.
Use a sanding block and fine sandpaper, to smooth-out high spots on the surface.
Texturing drywall by hand is an art, as different texture appearances are achieved, by using different tools and with different techniques. Large dents and damaged areas, often require experimentation and practice, to achieve good results.
You may want to try this: Buy some texturing compound and experiment on a scrap piece of drywall. Different texture patterns are obtained by using, for example, a stipple roller; wadded-up newspaper; clean, open-pore sponge; an old stiff paintbrush; a well-worn paintbrush; a trowel; an old toothbrush; a palette knife; etc. Or simply randomly splatter the compound on the board. Try different techniques, until you come up with a match.
You may also want to read about texturing, before you undertake your project. Most books on drywall and some books on painting contain details on texturing.
Filling narrow cracks
Cracks need to be opened. There was a time, when can openers were readily available with pointed tips, which worked well at opening beverage cans, but also well at opening cracks and removing loose material from wallboard and plaster. If you don't have a sharp-pointed can opener, use the corner of a metal putty knife or similar tool, to cut a groove about 1/8-inch deep.
One note: Not all cracks can be easily repaired. Some first require screwing the drywall to studs or joists, while others may need to be taped with joint tape. Here is an easy method for repairing hairline to 3/16-inch wide cracks.
Use a brush attachment to vacuum the crack well. Do not wipe down with a damp cloth, unless the patching material specifies that should be done.
Use a flexible and paintable caulking compound. IMPORTANT! Make certain the product you use is paintable, before you use it. A water-based product works well, as excess can be wiped away and blended onto the surrounding area. Always push caulk into a joint, instead of pulling it over a joint.
Repairing large holes & damaged drywall
Repairs, where something has punctured through the drywall, such as a doorknob or a large area of wall has been accidentally damaging when moving furniture, are "a picture is worth a thousand words" project. You will find illustrated instructions for making these repairs in "How To Patch and Repair Drywall" on the OSH Website.
If a doorknob has caused the damage, check the doorstop. If there isn't one, consider installing one. If the doorstop is damaged, replace it. Another consideration is to add a wall bumper, that is adhered where a doorknob may strike a wall. These are available in both paintable and un-paintable materials in the hardware department in OSH stores.
Hollow wall ("Molly bolt") anchor removal
You will need a pair of heavy-duty long-nose pliers and protective eyewear, preferably safety goggles.
Wearing protective eyewear, remove each screw from each hollow wall anchor. Use long-nose pliers, to grasp the outer edges of the flange (exposed metal face) of a fastener. The pliers are held at a 90-degree angle to the wall and tips of the pliers should be placed 90-degrees away from any notch or notches, and dig into the wall material. (If the flanges on the anchor you have do not have notches, then place each tip of the pliers anywhere on opposite sides of the flange.) An alternative method is to place the pliers, so that one tip is in the screw hole and the other tip is on the outer edge of the flange.
Firmly grasping the outer edges of the anchor flange, firmly squeeze and slightly twist to collapse the flange. Continue to collapse the metal, until the flange separates from the body of the anchor or the face collapses enough to be pushed through the wall material into the wall cavity.
Prime and then paint
Priming over repairs—in fact, priming all surfaces to be painted—is a good idea and usually results in the use of less topcoat and may eliminate extra coats. Priming also provides a bonding surface between the existing paint and the new paint you will apply.
Calling in a pro
Think the patching project is too large or matching texture seems impossible? Consider getting bids from drywall contractors for difficult repairs. They are usually listed in the Yellow Pages under "Dry Wall Contractors."
You will find instructions for how to repair drywall in most books on interior painting. These are located in OSH stores in the book section. Books on texturing are available through a library and new or used bookstore.
Where to buy
You will find sandpaper, putty knives, drywall patches, joint tape, spackling and joint compounds, paintable caulk, texturing compound, primer, and interior paints in the Orchard Supply Hardware paint department. Small drywall panels for dry and damp interior locations, which are excellent for most repairs, are available in the industrial section of the OSH hardware department. Larger sheets of drywall are available from lumberyards, building materials and drywall suppliers.