# improving adhesion of mud on painted walls



## d's

Hey gang,

I'm sometimes having a problem when tying new drywall into existing painted walls. After taping the joint and covering with three coats of mud, everything looks great until the painter applies primer and then some places bubble and peel right off back to the original paint. Most often happens when first coating with quick-set.

What's the best way to ensure that mud has sufficient adhesion when covering over existing painted walls and to repair these patches? Thinking of applying latex glue before coating or mixing it into the mud. 

Thanks


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## shanekw1

Try sanding the paint where the new mud will overlap it to get rid of the sheen?


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## Mellison

Plasterweld.


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## bamawildcat

Prime the place of adhesion first before you put mud over it.


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## flippinfool

I sand the old painted area's and add super-bond to my spackle.


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## ProWallGuy

Pretty much all of the above. If its a flat finish, sand it and tack it off. If it has some sort of sheen, sand it (if possible), and prime it with Gardz.


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## A+ Texture

Hey D's, so it sounds like your butting new rock against already finished walls, The sanding mentioned earlier is a good idea you might also want to try mesh tape with hot mud, thats how I do most repairs and transition joints. no complaints yet. Good Luck!!


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## Houston's

A+ Texture said:


> Hey D's, so it sounds like your butting new rock against already finished walls, The sanding mentioned earlier is a good idea you might also want to try mesh tape with hot mud, thats how I do most repairs and transition joints. no complaints yet. Good Luck!!


I just started using the mesh tape it is thin so it is eazer to float out the basterd jont.


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## d's

Thanks for the responses,

In this case I HAD used mesh tape and hot mud. I'm concerned that using hot mud might be part of the problem in that it doesn't bond well to painted surfaces. Perhaps rough sanding and applying primer,bonding agents, etc... will solve the problem. I've also considered using taping mud for the first coat.

I know that back when i did stucco we'd always paint on some latex glue before troweling onto sealed masonry - hence my idea of trying the same in this case.

I'll also add that existing walls are often not screwed or nailed on tightly and that it's good practice to rescrew around the joint.


D's


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## Preacher17

Hey D let me know how it works out for you.... I just had the same headache before christmas and had to go back for a touch up do to little pinholes (air pokets) in the mud on the old painted (well sanded) board....


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## mrp

Quick once-over with 80 grit.

Wash the walls with a good cleaner.

Wipe with liquid sandpaper if it still seems glossy.


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## d's

What's liquid sandpaper? TSP?

D's


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## Brocktologist

http://www.trim-tex.com/catalog/newtool.htm


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## Bob Mariani

d's said:


> What's liquid sandpaper? TSP?
> 
> D's


wilbond and other brands..


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## Frankawitz

I am doing a job now where some guy skim coat a living room wall with Durabond then the home owner wallpapered, well now they had a plumbing leak and all this skim coat is coming off with the wallpaper, I found that he tried to cover peeling paint, instaed of scraping the paint off down to the plaster he covered it up, So now I am scraping all the old paint off down to the plaster walls. anytime you have new butting up to painted walls or ceilings I always sand the painted surface with 80 grit, you can wash with TSP it will knock down the painted surface too. but if you have paint peeling make sure you scrape it cause even plaster weld will not hold once you apply primer or paint. Good luck

www.frankawitz.net


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## wopachop

man i wish they sold durabond in socal ive called around nobody has it. 

need to skim coat and re texture a small painted bathroom. plan is to hit the walls with 80 grit...prime with gardz if i can find it...then skim with setting compound...finish with the lightweight premix usg mud...then orange peel spray texture with regular usg in the green box. sound right so far?

problem is im super slow at spreading mud..so i buy 90 (dont laugh)....but after reading this thread im trying to learn if 20 min will adhere better than 90 because of the differences if composition?

how would you guys do it? i hope to find an additive not sure what they sell down here im in san diego.

small bath glossy finish...thanks for any advice


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## Frankawitz

The thing about putting self setting mud over paint, I am doing a job right now where a painter came in and told these folks, he could fix their problem. Well he skim coated over peeling paint with Durabond, then primed it and then covered that with wallpaper, Well they had a water leak from a upstairs bathroom, So I came in to repair it, I strpped the wallpaper and the paint and Durabond came off with the wallpaper in areas and in other spots it held I had to spend 6 days scraping all the paint and Durabond off the plaster wall that was 30'x 9'6" I primed the plaster and spotted it out, Just make sure you break down the paint finish cause if not when you go to prime and paint it could bubble on you and you'll have to scrape it all down and start all over. Good luck

www.frankawitz.net


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## d's

Have done a couple of jobs recently that illustrate this problem and what can happen.

Job 1: Skim coated 2 textured ceilings(same house).
Sprayed them both down before removing - one peeled right off and the other held fast and only the "tits" came off. After skimming, the one that peeled blistered a little and required touching up after painting. The one that held was solid right through. Given that the first one peeled so easily I should have sanded and primed first.

Job 2: Nail pops and exhaust fan patch in bathroom with glossy enamel paint.
When I rescrewed and cleaned up the poped nails the paint peeled off easily. I made the call that the HO needed to scrape it all off, sand, and prime. He was understanding and actually remembered how crappy the paint was when he did it 15 years ago. Waited the extra day then patched everything up and now it's looking bomber - extra work up front but would have been call backs otherwise for sure and he was more than happy knowing it was done right.

Job 3: Tying into existing wall - 12ft vertical joint - glossy paint.
Sanded with 80 grit but barely made a dent in it - had no primer so I sprayed it with my can of 3M adhesive that I use for plastic bead and quickly coated with hot mud then finished. Still hasn't been painted so fingers crossed but seems to stick like crazy and it's a quick, easy, and economical solution.

Just goes to show that every surface needs to be treated differently!

Thanks again for all the tips!
D'S


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## Golden Gate

*adhesion problems*

When I have adhesion problems or transition issues I found that using durabond 5min plus a pinch of accelerator at the last possible sec for the most part usually solves the problem..IMO. Knocking the shine off certainly works but it is exactly that extra work


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