Moldex

How To Patch Drywall

No painter is better than their ability to patch walls. That’s why wall repair skills are worth mastering. Learn how to deal with the four most typical wall damage situations right here and you’ll be a better painter for it.

Patching Old Nail and Screw Holes

patching nail and screw holes

The key to invisible repair here is something call dimpling. Grab the handle with your fist, with the rounded end of the handle pointing towards the wall. Give the nail hole three or four good hits with the end of the handle to create a dimpled depression in the drywall. This creates a place for a critical mass of spackle to sit, harden securely and get sanded later. Less obvious but more important is the way dimpling drives down any loose paper fibers around the nail hole. Nothing will be sticking up above the wall surface when you’ve pounded a nail hole properly, and that’s what you need.

drywal patching and sanding

Next, open your tub of spackle, dip into the compound with the corner of your drywall knife, then smear the spackle into the hole. Swipe some on generously at first, followed by removal of most of the excess with a second or third swipe of your drywall knife. The ideal result has the whole dimpled area filled, with the level of spackle slightly higher than the surrounding wall.

When the spackle feels dry, gently start sanding the area with your 80-grit sanding sponge held flat to the wall. If you run into gummy or moist looking compound, stop sanding.

You need to let the patched zone dry more. As you sand, use a circular motion over the patched area, extending out beyond it. The aim is not just to smooth the dry spackle, but also to ease the transition between the patched zone and surrounding wall. There’s nothing as effective as a bright light shining at a shallow angle across the wall to highlight areas that need more sanding. Don’t get lazy and forget the light. When you’ve finished with the 80-grit sponge, repeat the process with the 120-grit to make the area smooth. As long as you used a spackle that’s ready to paint after it dries, no primer is necessary.

Fixing Drywall Screw Pops

drywall screw pops

There are four steps to this job: removal of all existing drywall compound over the screw head; tightening the screw with a hand-held screwdriver; filling the space over the screw with spackling compound; then sanding the hardened spackle with a sanding sponge.

The tip of a utility knife with the blade pulled in is an excellent tool for picking out compound from screw pops. Clean old compound from the Phillips head of the screw, then tighten the screw so the head sits just below the surrounding drywall surface. At this stage you should have a smooth, slightly recessed screw head with frazzle-free dry- wall around it. Now’s the time to get out your drywall knife and your tub of spackle, then swipe a coat of filler into the slight depression. Apply enough to fill the space, with the compound sitting slightly higher than the surrounding wall – just like you did with the nail hole repair.

Leave the compound to dry, then take your 80-grit sanding sponge and rub the area with circular motions to smooth and level it. This work doesn’t take much pressure, but it does take a good eye. You want to sand enough to make the patched area flat, but not so much that it starts to become dished again. Use a hand-held light when sanding.

Fixing Holes as Big as a Walnut

fixing large holes

Removing big wall anchors can sometimes leave ugly, gaping holes, and so can impacts from door knobs and over- enthusiastically propelled kids’ toys. Frazzled edges of the paper around the edges of the hole poses the first challenge, and you’ll need to do some surgery with your utility knife to fix the problem. Break off the tip of your blade if it’s not sharp, then make a circular cut that encompasses the entire damaged area.

Apply enough pressure on the knife to go right through the paper in one pass. Lift one corner of the paper with the tip of your knife, grab it with your fingers, then pull the paper off, ideally in one, donut-shaped piece. The objective is to create a smooth, frazzle-free transition where the undamaged paper meets the area of wall damage. If any paper frazzles are present, they’ll stick up and remain visible after filling. That’s why cutting the paper cleanly is key.

Now’s the time to fill the clean cavity you’ve created, and setting type compounds are the thing to use. These come as a powder that you mix with water into a paste. Once the water has been added, the paste gets hard by chemical reaction. How long does it take? That depends on the product you’ve chosen, but cure time is generally 45 to 90 minutes. Some setting type compounds are meant to be sanded after they’re hard, and others are unsandable. Sandable compounds are better because they can be smoothed with your sanding sponge before going on to the final filling step with spackle. Add water slowly to the powder until the mixed consistency is similar to spackle, then use your drywall knife to smear the setting compound into the cavity. Smooth it over so there’s no excess above the surface, then let it harden. This is not the final filling stage, only the first of two stages.

Next, apply spackle so it’s fairly smooth and a tiny bit higher than the surrounding wall – just like you did before.

When the spackle has dried, sand the area with circular motions of your sanding sponge, making sure the area of patching feathers away to nothing as it meets surrounding drywall. Start with the 80-grit sponge and finish with the 120-grit.

Repairing Holes Bigger Than a Walnut

fixing large holes

When drywall holes are big, the initial coat of filler you apply will just flop out. This is when adding strips of wood to form a backing becomes necessary before filling.

Start the repair process using the same method of cutting frazzled paper from the perimeter of the hole and remove loose chunks of drywall in the middle of the damage zone. Next, use drywall screws to secure strips of wood behind the hole. These can be 1/2” thick plywood or strips of 3/4” soft- wood. Overall width of about 1 1/2” works well. Just use a handsaw to cut the strips 3” or 4” longer than needed to span the opening, extending at least 1” into areas of drywall with undisturbed paper above them. Use a single drywall screw to secure each end of each strip. Keep adding strips like this until you have the space covered, with about 1/4” of space between each strip. You won’t be able to hold the last strip with your fingers, so drive a single screw part way into the middle of the strip as a handle, move the strip into position into the last remaining area of the hole while holding onto this screw, anchor both ends of the strip with two more dry- wall screws, then remove your handle screw.

Fill the area using setting type compound like before. For repair areas larger than a grapefruit, you’ll find it easier to spread the compound using a 12” plasterer’s trowel, not your drywall knife. The plasterer’s trowel is longer and better able to create smooth, wave-free results. If any significant craters remain after this initial filling, you may need to apply setting compound again, followed by a coat of spackle and sanding. Smooth the surface with circular motions from a sanding block, feathering the edges of the repair zone seam- lessly with the surrounding wall.

Fix Small Cracks Fast
Drywall joints often develop non-expanding cracks, and latex caulking is the easiest way to fix them. Scrape off any loose paint around the crack, then smear in some latex caulking with your finger. Scrape off all caulking that’s on the surface of the wall, let the remaining caulking dry, then paint.

Basic Wall Patching Tool Kit

Wall Patching Tool KitEvery painter needs a wall prep kit that contains these essentials:

Utility knife:
You’ll use this to slice drywall paper and loose bits of drywall away from areas of damage. My favourite type of utility knife for wall patching uses the widest type of segmented blades.

Drywall knife:
A 4” model is best and it’s important that you keep your drywall knives clean and polished so they slide over the spackling compound smoothly.

Wall patching compound:
There are many different kinds available, but my current favorite needs no priming
before painting.

Couple of sanding sponges:
Sanding sponges come in different grades and I keep two types in my own kit: an 80-grit and a 120-grit.

 

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