If you need to repair a painted wall, you’re probably wondering, will drywall mud stick to paint?

The answer is, sometimes. Drywall mud will easily stick to flat paint and primer. 

Semi-gloss paints and those with a higher sheen are too slick for the drywall mud to adhere to. 

In this case, you’ll have to make proper preparations before applying the joint compound.

How to Apply Drywall Mud to a Painted Wall

Putting drywall mud on a painted wall is a straightforward process. Here’s how to ensure the joint compound properly adheres to the wall:

  • Scrape off any excess drywall or chipped paint
  • Wash the wall with TSP
  • Apply a coat of primer to the area you need to apply drywall mud to
  • After the primer is completely dry, use your drywall mud

After you’ve finished the drywall mud by sanding, you can apply another coat of primer and then a coat of paint.

How Thick Does Drywall Mud Need to be on a Painted Wall?

The thickness of the drywall mud will depend on what you’re fixing. The end goal is to have the patched area blend effortlessly with your already painted walls. 

The best way to achieve this is by applying several very thin layers of joint compound to the new drywall.

When you’ve achieved proper coverage, you can sand the drywall mud to finish it.

Start by using 120 grit sandpaper to knock down any rough ridges or uneven areas. Next, use medium-grit sandpaper to blend the drywall mud in with the existing wall. 

Finally, finish with 220 grit sandpaper. This will leave the area smooth and ready for primer and paint.

Will Drywall Mud Stick to Eggshell Paint?

Joint compound will stick to eggshell paint. To increase the sticking power, consider washing your walls with TSP before applying the joint compound.

TSP (trisodium phosphate) is a heavy-duty cleaner that will remove any grease, dust, and etch the wall, making it ideal for joint compound adhesion.

Will Joint Compound Stick to Semi-Gloss Paint?

Joint compound will not stick to semi-gloss paint. Unfortunately, the sheen of this paint makes the wall too slick for the joint compound to adhere to. 

If you have semi-gloss paint, you’ll need to put primer on the areas you’re using joint compound. After you’ve repaired the wall, you can repaint it. 

Will Joint Compound Stick to Primer?

Drywall mud will stick to primer. 

So if you have a slick wall surface, like satin or semi-gloss, you can use a coat of primer over top of it to create a surface for the joint compound to stick to. 

You can even skim coat over primer.

Will Drywall Mud Stick to Oil-Based Paint?

Oil-based paint is naturally very glossy and does not provide a surface for joint compound to stick to. 

So no, drywall mud will not stick to oil-based paint, and even if it does initially, there’s a chance it will eventually flake off.

Will Joint Compound Stick to Satin Paint?

Some brands of joint compound will stick to satin paint. Since satin paint does have a slight shine, it’s safer to put the first coat of primer over the area you need to mud since all joint compounds will stick to primer. 

Conclusion

If you need to use drywall mud on a painted wall, you can easily do so on flat or eggshell painted surfaces. 

If you painted your walls with satin, gloss, or semi-gloss, simply apply a layer of primer to the area you need to drywall

The primer will provide a matte surface for the joint compound to stick to.