How to Thicken Runny Wallboard Joint Compound

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Written By
Sal Marco
Sal Marco
Published: Sep 28, 2011
Updated: Nov 20, 2021
2 minute read

Adding excessive amounts of water causes wallboard joint compound to become runny and unusable. Thickening the compound makes the wallboard joint compound usable.

Things You Will Need

  • Paddle mixer
  • Power drill
  • Powdered joint compound mix
  1. Install a paddle mixer on a power drill. Submerge the mixing paddle into the runny joint compound. Turn on the power drill to mix the compound thoroughly. Sometimes, joint compound appears runny because the compound isn't properly mixed.

  2. Sprinkle enough powdered joint compound over the top of the runny mix to create a thin layer. Match the joint compound powder mix to the existing joint compound. Use drying-type only with drying-type and setting-type only with setting-type.

  3. Submerge the paddle mixer into the joint compound. Turn on the power drill to mix in the powder into the existing wallboard joint compound and thicken it.

  4. Check the wallboard joint compound consistency to determine if sufficient thickening occurred. If the joint compound remains runny, slowly add more powder mix and blend it in with the paddle mixer until the wallboard joint compound develops the correct consistency.

The Drip Cap

  • Joint compound comes premixed or as a powder that when mixed with water to forms a thick, pliable paste.
  • Submerge the mixing paddle into the runny joint compound.
  • If the joint compound remains runny, slowly add more powder mix and blend it in with the paddle mixer until the wallboard joint compound develops the correct consistency.

Photo Credits

Jupiterimages/Photos.com/Getty Images

Jupiterimages/Photos.com/Getty Images

Sal Marco

Sal Marco began writing professionally in 2009. He has written many online home improvement articles based on his more than 20 years of experience in the home improvement and building industries. He has worked as both part of a team and as…

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