When it comes to interior walls, drywall has a lot going for it. It’s inexpensive, fairly easy to install and repair, and holds up well to life in the average household. But drywall requires fairly extensive sanding before it can be painted—unless you like the look of bumpy, lumpy walls with visible creases between the joints. And sanding drywall means dust. So much dust, in fact, you might be tempted to build with medium-density fiberboard (MDF) instead. But while MDF doesn’t demand as much sanding to provide a nice, smooth surface for paint, it responds poorly to fluctuations in humidity, tending to crack from expansion and contraction.
Fortunately, with the right technique, you can wet sand drywall to cut way down on dust and still get an ideal surface for paint. Read on for pro tips so you’ll know what to do—and what not to do—to achieve flawless results.
I’ve worked on a few drywall projects myself, and let me tell you, the dust from dry sanding can feel like a snowstorm in your living room. Wet sanding has been a game-changer for me, especially in smaller spaces where ventilation is tricky. According to industry estimates, dry sanding can produce up to 80% more dust than wet sanding, which not only makes cleanup a hassle but can also pose respiratory risks if you’re not wearing a mask. Wet sanding, while slower, keeps the air cleaner and your lungs happier. Plus, it’s satisfying to see those joints smooth out without creating a mess!
DO be patient.
Wet sanding is time-consuming: If you’re really in a hurry to finish prepping drywall for paint, you’re better off dry sanding. Though keep in mind, when you dry sand, you’ll still spend quite a bit of time cleaning up the dust. Wet sanding drywall requires minimal cleanup, so the overall time spent is comparable for the two methods.
Patience is key here. I learned this the hard way when I rushed through a wet sanding job and ended up with uneven patches that needed redoing. Wet sanding can take about 20-30 minutes per 10 square feet, depending on the condition of the drywall mud. To make it less tedious, I like to break the work into smaller sections and play some music to keep the vibe light. Pros suggest setting aside at least an hour for a standard-sized room to ensure you’re not cutting corners. This method rewards a steady hand and a calm approach, so don’t rush it—your walls will thank you.
DON’T expect perfection.
Wet sanding drywall generally leaves very gentle waves in the finished surface, due to the flexible nature of the drywall sponge. This can be turned to your advantage if you’re patching a textured wall; it’s much easier to match texture with a damp sponge than with sandpaper. Just use your sponge to dab, wiggle, and pat the drywall mud—which is used to conceal the tape that holds sheets of drywall together—until it matches the texture you’d like to duplicate.
Those gentle waves can actually add character, especially if you’re going for a rustic or textured look. In my experience, trying to chase a mirror-smooth finish with wet sanding is a bit like chasing perfection in general—it’s not always realistic. The sponge’s flexibility means you’re working with a tool that’s more forgiving than sandpaper, which is great for blending seams but less ideal for ultra-flat surfaces. If you’re aiming for a high-gloss paint finish, you might need a final light dry sand with fine-grit sandpaper (like 220-grit) to get that flawless look. Just be ready for a bit of dust if you go that route!
DON’T skimp on water.
Wet sanding calls for plenty of water, so use a five-gallon bucket, and fill it three-quarters of the way with warm water, which helps soften the drywall mud. This way, you won’t have to stop and refill your bucket too often.
Warm water is a must—cold water just doesn’t soften the mud as effectively, and you’ll end up working harder than necessary. I usually keep a thermometer handy to aim for about 100-110°F; it’s a small trick that makes a big difference. A five-gallon bucket might seem like overkill, but it’s worth it to avoid constant refills. Fun fact: drywall mud, or joint compound, is made of gypsum and other water-soluble materials, so the warm water helps break down its surface tension, making it easier to smooth out. Just make sure your workspace is protected with drop cloths, as water can drip and make a mess if you’re not careful.
DO use the right sponge.
While any stiff sponge will do the job, you’ll get the best results with a drywall sponge specifically designed for wet sanding (like this one, available on Amazon). These specialty sponges are thick and stiff, with one side slightly abrasive for the first pass of sanding and the other side is soft and fluffy, for the second pass of smoothing the drywall mud. Submerge the sponge fully in water until it’s soaked, then squeeze out the excess so that the sponge is damp but not dripping. If sanding a full wall, have two or three sponges available, in case one wears down too much or tears during use. For small patching jobs, one drywall sponge should be sufficient.
I’ve tried using regular kitchen sponges before, and trust me, it’s not worth the hassle—they wear out fast and don’t give you the control you need. A good drywall sponge costs around $5-$10, a small price to pay for the time and frustration it saves. The abrasive side is usually made with a slightly gritty material, like a mild scouring pad, which helps tackle those stubborn ridges. For a pro tip, I keep a spare sponge soaking in the bucket while I work; that way, I can swap it out quickly if the first one gets too gunked up. It’s all about keeping the process smooth and efficient.
DON’T rub too hard.
Wet sanding drywall is somewhat tedious, but resist the temptation to speed the process by scrubbing aggressively at lumps and rough patches in the drywall mud. Doing so can create craters and holes you’ll end up having to fill. An overzealous approach can also lift or tear the drywall joint tape underneath the mud.
I’ve made the mistake of going too hard on a bumpy seam, only to end up with a divot that needed another layer of mud to fix. It’s frustrating to backtrack like that! The key is to let the water and sponge do the heavy lifting. Think of it like polishing a car—you’re gently working the surface, not grinding it down. Joint tape is especially delicate when wet, as the adhesive can loosen, so keep your pressure light and consistent. A good rule of thumb is to use about the same force you’d apply when wiping down a countertop.
DO focus on bumpiest areas.
Start off with wide gentle strokes to soften the entire stretch of drywall mud, and then focus on the uneven or ridged areas, using circular motions to smudge out the imperfections. Let the sponge and the water do the work—not the strength of your hand. Aim to smooth away imperfections without creating valleys or holes.
When I’m wet sanding, I like to step back every few minutes to check my progress under good lighting—it’s easy to miss small ridges otherwise. The bumpiest areas are usually where the drywall tape meets the mud or where you’ve applied a thicker layer. Circular motions are great because they mimic the natural blending of the compound, creating a seamless look. If you’re dealing with a large wall, consider using a pole sander with a sponge attachment for those hard-to-reach spots—it saves your arms and keeps your strokes even.
DON’T forget to rinse and rewet.
As you work, your sponge will collect drywall and mud, reducing its ability to smooth away imperfections. Remember to rinse your sponge thoroughly in the water bucket whenever it becomes too dirty, and then squeeze out excess water before returning to your task.
I can’t stress this enough—rinsing is your friend. A clogged sponge is about as useful as a dull knife. I usually rinse after every few square feet, especially if I’m working on a heavily mudded area. If you notice the sponge starting to drag or leave streaks, that’s your cue to dunk it back in the bucket. For an extra tip, I sometimes add a tiny drop of dish soap to the water—it helps break up the mud and keeps the sponge cleaner for longer. Just don’t overdo it, or you’ll end up with bubbles everywhere!
DO change the water as needed.
The water in your your bucket will turn milky and thick after several rinses of the sponge. Dump the murky stuff and refill the bucket with fresh water to make it easier to clean your sponge. If pouring the water down your sink drain, flush with hot water to prevent any buildup in the pipes.
I’ve seen that milky water turn almost like thin pancake batter after a few rinses, so don’t let it get too gross before swapping it out. Changing the water every 10-15 minutes of active sanding keeps things efficient. If you’re working on a big project, you might go through a couple of buckets’ worth. To avoid clogging your drain, I like to strain the muddy water through a paint strainer before pouring it out—it’s a cheap way to keep your plumbing happy and avoid costly repairs down the line.
DON’T make more than two passes.
The worst of the ridges and bumps should be erased during your first pass with the abrasive side of the drywall sponge. During the second pass, focus on smoothing the edges of the drywall mud and achieving the most perfect surface possible, using the fluffy side of the sponge, designed to minimize small imperfections. If two passes aren’t enough, you’ll need to let the drywall dry, and then use sandpaper to finish the job. Repeated wet sanding beyond two passes soaks the drywall too much, leading to craters, valleys, and melted spots.
Two passes is really the sweet spot—I’ve tried pushing for a third, and it’s a recipe for disaster. The drywall starts to get soggy, and you risk damaging the paper surface, which can mean starting over. If you’re not happy after the second pass, let the wall dry overnight and hit it with a fine-grit sandpaper (like 150 or 220) for a quick touch-up. This hybrid approach—wet sanding first, then dry sanding for finesse—can save you time and still keep dust to a minimum. Just make sure to vacuum up any residual dust before painting.