# Mud not sticking



## Davey (10 mo ago)

I was a member on here years ago but quit doing drywall for a good while, consequently forgetting some of what I knew. And having some skills deterioration.

This week I had to help my grandson drywall his new shop and ran across an irritating problem. We were using brand new green board, All Purpose mud and on the second coat with each pass using a loaded knife, many spots showed up where the mud wasn't sticking. 

I adjusted the water/mud ratio but that didn't help. The only way to eliminate those spots was to use a fair amount of knife pressure. which then caused the tape to show through. Then we had to go back and re-cover those areas.

What caused that and how do I keep it from happening?


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## Led Head (11 mo ago)

It's difficult to say exactly why it may be happening. A couple POTENTIAL causes are if the boards are dusty/dirty. If you're sanding in between coats, an excess of dust could make the mud not adhere as well, but it would have to be a lot of dust for that to happen. Another could be if there's some oil of some kind on it. It may cause the mud to not adhere properly.

i don't know if any of those apply to your situation but are a couple of possibles.


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## Davey (10 mo ago)

Not sanding the first/taping coat, not a dusty environment, boards are bound in pairs face to face so anything on them would have come from the factory. USG Sheetrock brand. Maybe my technique has gotten rusty, IDK. Don't do something for a while and you're not as sharp as you were.


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