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Several years ago, I was looking for a tutorial that would help me fix my damaged walls in the upstairs master bath. After removing all of the wallpaper, there were imperfections everywhere thanks to torn drywall paper. At the time, I was hoping that there was someone out in the web world who could teach me the right way to fix this problem. I didn’t know what “level 5 drywall” was. I didn’t know the tools I needed. And I certainly didn’t know the lingo.
Unfortunately, I couldn’t find a single tutorial that had all of my answers. So, I bumbled my way through a couple of walls, read various online forums, learned a few tricks, and combined all of that new knowledge into a lengthy skim coating tutorial of my own. It’s not that I was an expert; I couldn’t skim coat like a pro. I still didn’t even know most of the lingo. But I found what worked for me, and I wanted to help other people with the info I’d spent hours collecting.
In reality, that’s pretty much my whole motivation with this blog, and has been from the beginning. I’m a chatty person by nature, and blogging just seems to fit, so I’ll throw in some crazy shit that has nothing to do with DIY every now and then too. But, I’m also a first time homeowner. I had no previous experience fixing things to this extent before moving in. My parents were avid DIYers themselves, so it taught me I could probably do things myself if I just found the right instructions. And therein lies the challenge: the right tutorial for me. Not one that talks to me like I’ve already done this 100 times, and not one that only gives me half of the information I need. Something in layman’s terms that also covers the obstacles I’m puzzled over.
So all of that to say: I needed an answer, I looked it up, collected any helpful info there was on the subject into a workable tutorial for myself, and kept going. More often than not, DIY is a learning process where at least one fuckup is bound to happen. But then you know what not to do, and your completed project secretly holds all of this badass juju from knowing that it was your sweat that made it a reality.
Of course, that also means you learn more new tricks and tips as you do the same projects over and over. I began skim coating in the master bath, but then there was the guest bath, the dining room, and now, I’m in the home stretch with my kitchen. I’ve dealt with a few more puzzling obstacles with each subsequent room, and despite the frustration, I’m probably better for it (at least for the next house, whenever that may be). Perhaps it was the difference in material (both the wallpaper and the drywall); perhaps I was just less careful and created bigger problems. I’m willing to bet it was a combination of both. This house taught me new lessons about skim coating, long after I’d written what I thought was a comprehensive tutorial. I’m essentially back in the same position I was several years ago: I’ve run into new problems, and thus had to figure out new solutions. And then, once again, pass this new knowledge on to you.
If you’re just starting out with skim coating, you should still read my first tutorial here. That covers most of the tools I still use, where to find them, a little lingo, and the basic steps for getting a smooth finish. Then, come back and read the rest of these tips as a supplement to that tutorial. I’ll be right here when you get back.
How to prevent bubbles in the drywall: This was a new discovery for me, as both of the upstairs bathrooms didn’t have this happen. But once I started on the dining room and kitchen, I realized that there was a crucial step I’d missed (and hadn’t really needed yet). Bubbling happens when the paper layers in the drywall become separated. While it may not seem like it’s loose, you may find out differently once you slap your first layer of joint compound on the wall. Bubbling still happened for me, even after checking the wall numerous times. I thought I’d gotten rid of any problem areas. And like me, you may find that all of the prep work in the world will still turn up a bubble or two. It’s entirely defeating to see it happen, because it means a new problem to fix. And it doesn’t really get much better with adding more layers of joint compound, so I discovered that the best thing to do is to seal the surface.
The first attempt to solve this problem was with oil primer. In fact, some pros who commented were very insistent on this after they discovered my first tutorial. Enough commenters gave the same tip that I was sure their ringing endorsement would work – so I put it on every wall in the kitchen and dining room. Its purpose is to essentially harden the loose drywall paper, making it that much more unlikely to cause bubbles. But after giving it a shot, I didn’t seem to get anything out of it except more bubbles and an unfortunate stink from the fumes (be sure to read that sentence in context, ha).
Cue the sad trombone. I was pretty disappointed, since it seemed like such a sure thing. But when it comes to DIY, there is usually more than one way to do something. People give their advice and you hope it works; and yet sometimes, your house just doesn’t fit the mold.
I did a little more research the second time around, and the online forums (of pros/experienced DIYers) seemed to all recommend the same product: Gardz. I’ve had pretty good results with other Zinsser products before, so I went on the hunt to find it. Only trouble was, it didn’t seem to be available except to order online. In large contractor quantities. And the smaller-sized products had been discontinued. No bueno.
The third (and thankfully, final) attempt worked. I found a product that was available at my local HD called Rx-35. Unlike most primers, this goes on more like glue (it looks like skim milk in the can, actually), but it seems to do the trick and seals the drywall paper.
I’ve experienced a world of difference with using this before applying joint compound… far less bubbling (aka “rage-inducers”). It’s not perfect, and I’ve heard Gardz is even better, but the convenience of finding the right product is often just as important as knowing what it is in the first place. It always frustrates me to read about the usefulness of something and then discover I can’t get my hands on it for weeks. Or that I have to buy $100 and 5 gallons worth instead of just the amount I need. So even if Gardz is, in fact, better, I can honestly recommend Rx-35. Use this after taking your wallpaper down and before your first skim coat for a smoother finish.
How to get rid of bubbles once they’re in your skim coat: Ok, this part sucks. But until I found the right product to help prevent them, I had to do this a lot. And even after getting a good sealer, it is still not 100% foolproof, so I have to still work out a bubble from time to time. As I mentioned above, putting more coats over a bubbled area doesn’t really help matters much since it just wets the paper again (which actually runs the risk of bubbling more), so the best way to get rid of a bubble is to get rid of the paper that’s causing the issue. This means digging into the drywall again to remove the paper causing the bubble (I’ve done it both while the joint compound was wet and when it’s dry… wet is messier and peels up more paper, sometimes maybe more than you needed to). The tip of my taping knife worked great for getting under the bubble and removing the problem.
Then I allowed it to fully cure (if it was wet), and fully saturated the area with the Rx-35 sealer. It doesn’t take very long for this stuff to dry, so don’t worry too much about this putting a lengthy hiccup in your progress. After all, it’s better to remove them rather than seeing the bubbles in your paint job (spoiler alert: they only become more noticeable).
Then patch up the area with more joint compound. Easy, but time-consuming. So do yourself a favor, and prevent this as much as possible. You’ll damage your liver less by not drowning your frustrations in beer.
Learn which joint compound types you need and are easiest to worth with. In the first tutorial, I shared some info on what kind of joint compound (aka “mud”) to look for and where to find it. At the time, I was using regular all-purpose joint compound (with a green lid), but I’ve since switched to a lightweight version that produces less dust (or at least, claims to, with a blue lid). I’ve found that switching this up did help me to get a better finish on later projects, but it’s more prone to scratching (so prime that wall asap when you’re done!).
Always mix the joint compound thoroughly. I didn’t really find either of the types I’ve used all of that difficult to sand, but I did notice a difference between mixing and not mixing when it comes to sanding down the wall (on one or two occasions, I’ve been too lazy to mix up a new batch and have slathered the stuff on to fix a tiny mark in the wall, only to see it do this weird ridge-like lump after sanding). So, always mix the joint compound (I prefer to make mine a tiny bit runnier than some of the other tutorials will tell you to do, but find what works for you). Using a paddle mixer can be extremely helpful if you’re doing a lot of application in a single day. DIYDiva has a pretty great post (or two) on that.
Let the joint compound thoroughly dry before adding more. I get it. It looks dry. It feels dry. It may even feel dry enough to sand. But unless you’re working with the chemical-hardening stuff (that has a much shorter curing window of 20, 45, or 90 minutes), you need to wait 24 hours before applying a second coat. Really. It prevents cracks and other issues when the base layer isn’t fully dry. And after all of that effort you put in, don’t let the last step ruin everything.
Speaking of 45: There is an “easy-sand” joint compound product that also dries in 45 minutes. As with most of the other quick-drying stuff, you will need to mix this on your own from a powder form rather than buying in a pre-mixed bucket (like you would with all-purpose or the lightweight stuff). I haven’t used it yet myself, but I have considered it after watching this helpful video from Our Home From Scratch. Not just because of the quick dry, but using a compound that cures into a more rigid base may also help with the bubbling issue. (You’d still want to finish your final coats with the lightweight stuff.)
You don’t need to sand in between every coat. If you’re a beginner and aren’t confident about your technique, you can sand in between coats if you want. But I learned that you don’t really have to. You can easily scrape down dried ridges with your taping knife, and the last sanding job gets rid of just about everything else. The perfectionist in me wanted to get rid of everything immediately, but don’t forget that you are building a smooth finish, not creating one in the first coat.
Save time and mess with a vacuum attachment. The amount of dust you can accumulate when sanding drywall is a beast. Seriously. But instead of sanding by hand and looking like a ghost, I now use a shop vac and get rid of most of the drywall dust right from the start thanks to my Hyde drywall sanding kit. I highly recommend it. It’s cheap, easy to use, and can be used with a pole attachment as well. I’ve also used it for backsplash tile prep. It sucks up the dust so well that I don’t feel like I’m putting myself in harm’s way when I can’t find my dust mask (PSA: you should probably always wear them. Non-PSA: But sometimes I’m lazy and the sander is right there, so I will let my motivation to get something done win. This helps my lazy DY style, and I love it for that reason). Sandra from Sawdust Girl took my advice and used it in her dining room with excellent results as well. Just remember to buy a filter for your shop vac that is for drywall dust (fine particles), or you’ll wind up having to buy a new shop vac after choking the motor.
Scratches from sanding screens can often be fixed with the right primer. I noticed an increase in the number of superficial scratches I get in the wall when using the vacuum sander than when doing things by hand. The culprit is mainly sanding screens (recommended in my last tutorial), and the suction from the vacuum sticks the sander on the wall pretty closely. But I typically do a light pass with a sanding block after everything else is finished. It’s probably not even necessary, but makes me feel like I did everything I could to smooth out the surface. Still, slight imperfections may remain, which is why I’m also recommending Glidden’s Gripper Primer. It seems to fill in imperfections to where I don’t notice them at all when applying paint. Again, it’s not a miracle cure for everything, but does do the job for me on the smaller scratches where I worry that they will show up in the paint job. It also seals the drywall compound, which helps the paint to stick (I’ve seen it come off the wall before… talk about a ruined project on the very last step!). Want even more info? See my post on painting prep after drywall repair.
There have been other tips I’ve come across that I haven’t yet tried myself, but am open to trying now that I’m on the last room I need to fix (for a while, I hope). Chris from Picardy Project recommends a knock down trowel, which is a lot wider than most of the other taping knives I’ve grown accustomed to using. I think they would be fun to try out, but I’m also pretty sure my short stature means I’d look somewhat like a garden gnome using a snow shovel.
Most paint products (especially paint/primer combos) are formulated to work on walls that have already been painted. Not new drywall. Normally, when dealing with fresh drywall, you still want to prime separately, as it not only primes, but seals the joint compound (I’ve tried using some formulas in the past that scared me off for a while… fresh paint coming off the wall & back onto your roller is gross). But lately, I’ve heard good things about a couple of painting products that do not require separate priming before use. I’m still doing research to see if the reviews stack up to the claims, and you’ll hear about it (good or bad) if I try one out.
Since this is pretty much a novel at this point, why not add a conclusion, right? I considered chopping it up into smaller bits, but when I look for tutorials, I don’t like having to click around a lot. And that’s how 2600 words are made. Ultimately, DIY projects are about learning; you learn once, and then you learn again. And if you do the same project enough times, you might actually get very good at it. So good luck with your next project, and I hope these tips helped!
*Disclaimer: While some of the links in this tutorial include affiliate links that make me a few cents if you make a purchase through this website, I was not paid or perk’d by anyone to promote these specific brands or products. I always want to share with you what I found actually worked for me, and I’d hope you could guess by my potty mouth that these words are 100% mine!