How To Fix Bad Crown Molding Joints: Looking Good

You installed crown molding, but the joints didn’t line up right, so what can you do to fix it? Well, there are two different types of joints to worry about. First, you have outside joints that come to a point. Secondly, you have the inside joints that are inverted. Both are repairable, and you can use the same process. However, if you used unpainted wood, you need to remove and replace the section or paint over it. I’ll teach you how to fill in gaps and make it look like you did a perfect job. I’ll give you some tips and tricks for DIYing it correctly on the first try. Plus, Fortunately, all three fixes are simple enough to accomplish.

Prepare to Fix Your Bad Crown Molding Joints

Most people who have gaps in their crown molding don’t want to redo the whole job. Although I recommend doing exactly that, it’s understandable. Moreover, some people encounter a job done by the previous owner or corners that weren’t square to begin with, which complicates matters. So I’ll walk you through how to fix the seams with putty for a faster fix first.

Please note that this trick only works on painted crown moldings. If you’ve installed stained wood, then the only way to fix it is by replacing or re-cutting the molding completely. In this case, I strongly recommend the EasyCoper for Crown Molding. This ingenious copper helps you to get perfect angles on your cuts every time. All you need is wood and a saw. To pick yours up from Amazon, click here. 

Fix Bad Crown Molding With Lightweight Spackle

You’ll need a steady hand and a minimal amount of talent to pull this fix off. Since you need to make it look like the edges met the way they should, we’ll be filling the gaps and creating a false seam or corner with lightweight spackle. Ideally, you should be able to complete the Spackle in a few minutes per seam.

Keep in mind that spackle, like paint, needs a dry environment and several hours to a day to dry properly. Don’t start this project during a monsoon. Total work time is around two days, including dry-time, but you’ll only need to be hands-on for a few minutes at a time. Patience is key.

Tools For Fixing Bad Crown Molding Joints

An excellent angle cutting tool isn’t all you need to fix bad crown molding joints. For this repair, you will need everything on the following list.

1. Lightweight Spackle- Use this to fill the gaps and mold the new corners.
2. A Putty Knife- Because your fingers don’t make a good smooth surface, I recommend using the right tool for the job.
3. Sand Paper- You’ll want to use relatively fine grain sandpaper. Especially if you have big lumps when you finish, it’s okay to start with a larger grit. Work your way down to a very fine grain.
4. A Mouse Sander- This type of sander is excellent for working on corners. The BLACK+DECKER BDEMS600 is superb for small spaces and tight corners. More importantly, you’ll get the job done much faster than you ever could working by hand. You’ll love the compact size on this model and finger attachment for finishing tiny details. Read the Amazon reviews here.
5. Extension Cord- Your mouse sander likely needs an extension cord to reach the ceiling.
6. Caulking Gun With Caulk- You’ll use this to help fill the gap in your molding.
7. Matching Paint- You can choose to repaint the entire room’s molding in a new color or use the exact shade you had on the original. It’s up to you.
8. Painters Tape- This is how you get crisp edges and don’t make a mess.
9. Drop Cloths or Plastic Sheeting- To cover anything you don’t want paint or dust getting all over.
10. A Good Paintbrush- You can substitute a small roller or paint sprayer if you prefer. I prefer the YATTICH Paint Sprayer from Amazon. It comes with several different tips that allow you to do detailed work without making a mess. Plus, it has three spray patterns that help you get the best coverage at any angle. Find out more by clicking here.

Once you have your tools together, it’s time to get started with the repairs. Don’t worry if you’ve never done this before. It’s not as hard as you think. You should also use face coverings and eye protection while working with paint and sanders.

Steps For Fixing Bad Crown Molding Joints

There’s not much to fixing bad crown molding. Once you’ve done one joint, you’ll see just how simple it is. Feel free to make smooth corners, or add a fake seam as you like.

• If you haven’t installed the molding yet, then you’ll need to caulk it anyhow. Add extra caulk in any significant gaps to help stabilize the spackle. Doing this will save you time and help hold up both the molding and the spackle.
• Caulk doesn’t take long to dry, but make sure you follow the instructions and let it set up completely. Improperly dried caulking might peel away or have other issues. Plus, you don’t want any extra moisture left when you add a new layer of material. That could promote mold growth and adversely affect your health.
• Take your drop cloths and painters tape and cover the walls, ceiling, floor, and any furniture you can’t move. No one wants a dusty mess or paint all over their room.
• Next, use your spackle to fill any gaps. You can also use this to mold new corners. It’s a little different than clay, but the concept is the same. Do your best to make sure you push out any air pockets, so it fills the space completely. Use your putty knife to help make smooth lines.
• Blend it in by smoothing your spackle as best you can. You don’t need perfection in this step, but try to smooth out any lumps. Blend it into the molding by using the putty knife to remove excess and spread any overlap out to a very thin layer.
• Let your spackle dry then sand it down until it’s smooth and matches the molding perfectly. During this step, you need to be extra careful. Detailing to match and get the right shapes is likely the hardest part of the whole process. However, the good news is that you can add a second layer later and re-sand if you make a mistake. It will cost some time, but it’s always worth doing the job right.
• Now all you have to do is paint. Make sure you use a small sprayer head and a vertical setting. Round or horizontal sprays won’t help you make a smooth stripe. If you’re using a brush or roller, it can be challenging to get a perfectly smooth paint layer. They tend to leave very small, but visible stripes and texture.
• You can repeat this process anywhere you have imperfect joints. Take the time to fix all the messy corners at the same time so you won’t have to worry about putting all the drop cloths back up.
• Clean up your mess, and admire your work. There’s no need to watch the paint dry. It should look great even before the paint is set completely, though the color may change slightly from wet to dry.

Pro Tips for Fixing Your Bad Crown Molding Joints

Wet weather isn’t the only thing that can interfere with a perfect fix for those bad crown molding joints. I have five pro-tips to help you get the most out of your repairs.

First, take the time to make sure your sanding is exact. You can smooth more spackle over any accidental dings and sand again. It’s worth the extra effort of taking your time.

Next, to avoid weird lumps in your paint, you need to make sure all the spackle dust is gone. Take a soft cloth or a dry paintbrush and dust the surface before you paint. Also, you can add a great primer. I like the mold-resistant variety, but it’s up to you how ‘extra’ you want this project to be when complete.

Then, make sure you wear the right clothing and protective gear. Dress in something you don’t mind messing up. Eye coverings are essential in case of any drips or dust. Furthermore, you should always wear a cloth or face mask when working with sanders or paint.

Always ventilate the room you’re working in. Even when you don’t think you need it, open the windows. Set up a fan as well if you can to get good circulation. You don’t want paint fumes or dust fro your sander to get into your lungs.

Finally, take your dusty clothes outside and beat it like a rug before you wash. Spackle and wood dust isn’t suitable for a washing machine, and your clothing will get cleaner this way. Otherwise, wear something you can throw out.

Final Thoughts

There are all sorts of reasons people end up with bad crown molding joints. Fortunately, that doesn’t matter as long as you fix them. Getting a clean and perfect look doesn’t take very long unless you have to remove and reinstall the molding. If you used exposed wood, consider painting over it to make the fix easier.

If you’re starting a new crown molding project is a lot like removing and re-cutting a mistake. If you need tips and visual aids on how to accomplish the process from the start, then check out this video. You can see the whole process, which is very helpful, whether it’s your first time, or you simply need a refresher.

Don’t settle for funky, gapping crown molding joints. Not only will fixing the problem give you a beautiful look, but you also get a pleasant sense of accomplishment from a job well done.