One of our vanity doors is in very bad shape after a leak some time ago. Now I'm trying to save it if possible. I've managed to sand away the very bad swells

enter image description here

However the bottom feels rather fluffy. 

enter image description here

Can I just use any undercoat and paint it with any interior paint?

Any advice appreciated.

  • 5
    Dig it a grave, Salute, and Bury it. Why real woodworkers despise MDF, illustrated nicely.
    – Ecnerwal
    Apr 6, 2020 at 12:51
  • I agree with Ecnerwal you could try to build it up and repaint but by the time you did that you could buy enough wood to replace both doors. the filler will not hold or did not hold for long when I tried to save some decades back and it was a waste of time.
    – Ed Beal
    Apr 6, 2020 at 13:29
  • @EdBeal Is it a good idea to just build a new MDF following this tutorial? youtube.com/watch?v=xfDQkHrE6lc
    – John M.
    Apr 6, 2020 at 13:55
  • @Ecnerwal I wish I was more handy and more tools to replace it with a proper door.
    – John M.
    Apr 6, 2020 at 13:56
  • @JohnM. Make another door with MDF, and you'll be back in the same spot again one day. I use MDF in totally dry spaces like a pantry, but would never use it in a bathroom or kitchen. There's just too much risk of moisture damage.
    – JPhi1618
    Apr 6, 2020 at 14:17

1 Answer 1


Everyone has already noted in the comments how and why MDF is not a good material to use around water or moisture and that you'll likely have future issues so that is not addressed in this answer. This answer is for the case that you still wish to go forward with your work, perhaps as a temporary fix.

Can I just use any undercoat and paint it with any interior paint?

Because water is a no-go it is necessary to use an oil, alcohol, or lacquer based primer first and then, after sealing, you can use latex water based paint as desired.

Here is a couple of articles with other related information that might helpful

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.