# Yellow area and spot stains on recently drywall mud patching, anything to be concerned?



## ClarenceBauer (Mar 4, 2005)

daluu said:


> Contractors did the patching yesterday. I noticed the spots & coloring today, don't think they were there yesterday. Not all over the place but some areas have these observed.
> 
> I tried wet scrubbing some of the spot stains, which was in thin mudded area at the edge of patch where it is simply mudding over existing painted drywall (below the actual patched hole, above outlet/switch), and it seemed to just wipe/scrub the mud off. The mud itself doesn't feel wet, but not sure if fully dry, but should be 4-6 hrs away from 24 hrs at least.
> 
> ...


I would not worry about the brown stains.
It can occur from dust , dirt that has filtered thru the wall with moisture & air movement.
Also it could be burnish marks left from the use of a steel trowel.


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## Half-fast eddie (Sep 19, 2020)

If they used premixed mud ... comes in a bucket, looks like thick mayonaise ... it will be water soluble for the rest of its life. You can get it wet and it goes soft. But once it’s painted, the only way moisture can get to it is from inside the wall. So thats why it seemed soft when you were washing it with the wet cloth.


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## mark sr (Jun 13, 2017)

Unless there were stains there prior to the patch work I wouldn't worry about it - latex paint will hide the discoloration. IF it's a water stain you'd need to prime with a solvent based primer to seal the stain.


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