I'm about to start painting a small cabinet I've built, which has vertical dividers and a lot of dados where I don't want any paint to get inside. These dados are designed to keep removable dividers in place and I need to protect them while I spray paint. I've considered a few methods for masking off these areas, like cutting thin strips of MDF to slide into the grooves, but I'm worried about them getting stuck in the paint. I've also thought about using tape, but that seems pretty tricky. Has anyone figured out a solid technique for temporarily filling or masking dados while painting? Google hasn't been much help; I keep finding irrelevant info about respirators and wood filler. Thanks!
4 Answers
Another cool option is to use some expansion joint backer rod or foam. Just shove that into the dados, spray away, and then pull it out after you're done. It works great for sealing those gaps!
You could make a removable piece to slide into the dado. Just paint the areas around it and then take it out when you're done. This way, you won’t have to mess with any tape!
Honestly, just using tape should work fine. You might end up with a bit of overspray, but it shouldn't be too much to worry about. Just make sure you press it down well to minimize any gaps when you spray!
For future projects, it’s a good idea to apply your finish before cutting the dados or even make them slightly bigger, like 1/32 or 1/16 inch wider. This gives you some room for paint or finish without having to worry too much!

Thanks for the tip! I guess a bit of overspray is just part of the game.