How to Help Drywall Compound Stick
Drywall installers use drywall joint compound, commonly called mud, to tape seams and fill holes in newly installed drywall. When it dries, installers apply two or more coats of drywall compound on top to smooth the wall; then, if they are texturing, they often use the same material to do that. In most cases, mud readily adheres to drywall; but in the rare instances that it doesn't, it's usually because the mud is too thick, the wall is painted or greasy, or it is covered by a layer of fine dust. Hot mud, which becomes hard as it sets, won't stick when it becomes too hard. Does this Spark an idea?
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Things You'll Need
- Paint de-glosser
- Paint roller
- Trisodium phosphate
- Warm water
- Rubber gloves
- Power blower
Instructions
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Use a chemical deglosser to dull the finish if the wall has a coat of glossy paint. Mix the deglosser with water according to the instructions on the container and roll it on the wall with a paint roller. Let it dry completely before mudding.
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Clean grease off the wall with a solution of trisodium phosphate (TSP) and warm water. TSP is a strong detergent that cuts through even thick layers of grease, such as may be on a wall in a well-used kitchen. TSP is a skin irritant, so wear rubber gloves while using it.
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Blow dust from the wall with a power blower. It's normal for the wall to be dusty after you've spread one coat of mud and sanded it prior to applying a top coat. It usually doesn't interfere with subsequent coats, but it may if it's too thick.
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Thin the mud with water if it's too thick. A good way to gauge if it's too thick is to form a small amount into a ball. If it holds its shape, it needs to be thinned. Add just enough water to make it pliable without being pourable. It should have enough consistency to stick to an upside-down drywall blade without falling off but still be liquid enough to spread easily.
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Keep your fresh mud free of contaminants, like dried mud, paint chips, bits of drywall paper and dust. They not only interfere with adhesion, they leave tracks in the mud when you scrape it.
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Spread thin coats, even though it means you'll have to apply more coats to finish the job. Heavy coats can separate from the wall or crack while they are drying. They also take longer to dry.
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Discard your current batch of hot mud, clean your tools and mix a fresh batch if it becomes hard and doesn't stick well. Unlike regular mud, hot mud sets as it dries; once it has begun to set, you can't soften it by adding more water.
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Tips & Warnings
If the mud is cracking and flaking after it dries, the wall or the room may have a moisture problem that you should address before continuing.
If you're using hot mud, clean it off your tools and tray before it sets. If you allow it to harden, you'll have a much harder time removing it.
References
- Photo Credit Alex Wong/Getty Images News/Getty Images
