# Air bubbles when mud over paint.



## Drywall1

OK guys, me being the punchlist guy now I need a difinitive answer... how do I keep them damn air bubbles from causing me to put on 4-5 coats. I know why they come..so we don't need to go there.

Tried soap...no dice. Used brown bag durabond this am on a remodel project. We will see tomorrow. 

If patch only needs one light skim its OK but if more coats are needed its bubble city.


Used to just be me and one guy doing all the work, now I bid, patch and run around a lot. Man things were easier back in the day!

Nate


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## taper71

I think that you may just have to accept it as a fact of trade. I would certainly like to know a cure, but this topic has been the topic of discussion on three separate forums and I have yet to read one so far.


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## Drywall1

Sorry cant accept it.


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## savant

Well, It's not a materials quality issue under paper tape, so changing your materals won't help. 3M adhesive under cornerbead is always suspect under cornerbead for me, so it's never alone anymore. 

You have to determine whether it is caused by coverage, tape condition, or open time.

A tried and true patch method is to use a sharpened hypodermic needle from an ink-cartridge refilling kit to inject some mud or glue behind the paper, then ride the broken edges of the crater to flush the surface.


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## Drywall1

No man the bubbles are from the moisture not being able to soak into the paint surface and having to come out of the surface....thus air bubbles. You are talking about a whole different PITA.

Nate

BTW the brown bag DB worked well as a filler of the bubbles after they have shown up. We will soon see if using from the get go will erase bubbles......prob not!


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## Tim0282

If you prime the area with an oil base primer first, the bubbles won't sneak up on you. Primer like Zinser 123. Or SW Pro block. It's not as good. The Zinser leaves the surface kinda porous feeling. But.... I hate to prime first before I start working on the spot. Pittsburg Paint makes a good oil, also.


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## taper71

Quote from another drywaller on another forum
"A painted surface is not porous like drywall paper. The change in the mud temperature effected by the warmer ceiling will cause the disolved air in the compound to outgas. On unpainted drywall, the gas is able to dissapate through the face paper and not form "seeds" (like you'll see on the bottom of a pot of water as it nears boiling point), but not so on a painted surface.

Over-whipping the mix might add to the problem, but I think the notion of mixing air into the mud is too frequently offered as an explanation for this phenomenon, and leads people on a fruitless (and potentially expensive) search for better mixing methods. 

To stop this from happening, you would have to:

1- place the mud in a vaccuum to release the disolved gasses, or
2- heat the mud until it's warmer than the drywall and keep it warmer while working, or
3- Trowel repeatedly until the bubbles disappear (if the fill is shallow enough), or
4- Accept it. Sand off the bubble tops and fill."

This is by far the best explanation that I have read.


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## bob16

The worst air bubbles i ever ran into were solved completely by an additional skim coat (2 skim coats in total)

They really aren't that big of a problem. Just price for it when you bid the job.


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## Drywall1

bob16 said:


> The worst air bubbles i ever ran into were solved completely by an additional skim coat (2 skim coats in total)
> 
> They really aren't that big of a problem. Just price for it when you bid the job.


Its a little hard to price for punchlist. The Brown bag Durabond seems to be working the best. If you know how to leave a patch its not bad sanding either.

I dont buy the temp thing. Ive used hot water before and it still bubbles up. 

I will try the zinser primer though. 

Thanks for the replies guys.

Nate


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## Tim0282

You are some what correct that a painted surface is not porous, but a primer surface is. So the finish will adhere properly. You can tell the difference between the primer and the finish by the feel. The finish is slicker. The primer is rougher.
Nothing works completely every time. Too many variables. Brown bag durabond and a light skim sounds like a good bet. Maybe we could try thinning the mud with Pepsi or Mountain Dew. Just might work... After the fizz is out of the drink and at room temp. Ummm... another plan for tomorrow.


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## Drywall1

:thumbup::thumbup::thumbup:


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## butcherman

On painted surfaces what has worked for me is 2 things. Plaster weld on smooth (semi gloss over plaster) surface. On reg drywall mix ez sand a little watery throw a hand full of plaster on the hawk and mix together. Then prime the area with this mix larger then the work area. The trick is to get the mix to dry in minutes. This way the paint don't bubble and peel. When paint is wet it peels and bubbles. Don't give it the chance.


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## cooper

How bad are these air bubbles that you are coating them 4 or 5 times... ? Easy fixes are mixing the mud longer and more thorough, using a little more water to thin down the mud, and switching materials. I don't know what mud you have access to, but Beadex lite all-purpose is the least porous of the all-purpose muds that I have used. USG and Hamilton have more issues with air bubbles than Beadex. 

Taping is interesting like that though because the muds I use may be terrible in your climate--tough to say. I have never heard of anyone having to touch up something 4 or 5 times to get rid of air bubbles. If you can't coat it twice, maybe touch up a couple spots and be done then something is not right.


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## brdn_drywall

WOW just sand the paint with an 80grit paper you won't get em if mud if mixed well enough


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## wnybassman

brdn_drywall said:


> WOW just sand the paint with an 80grit paper you won't get em if mud if mixed well enough


This was going to be my reply to. Sanding the paint has worked halfway decent for me. Still get some bubbles, but not nearly as bad. Gives the compound something to grab onto as well.


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## KingOfDrywall

"No man the bubbles are from the moisture not being able to soak into the paint surface and having to come out of the surface....thus air bubbles. You are talking about a whole different PITA."--------((EXACTLY))--I used to run into this situation alot because my business is mainly repairs, and we are always going over painted surfaces. We have a rule here, whenever we go over a painted surface we NEVER use anything less than 5 or 20 minute quickset easy sand. Actally it's pretty simple. Air bubbles are gonna be an issue when going over a painted surface. Coat with the 5 minute. Do a light sand with a hand sponge OR my favorite is work the mud while it's setting up with a stainless steel knife...1 coat looks like glass. Pull a 2nd tight coat with 5((wipe on-wipe off)). After 2 coats of 5 minute easy sand it should look like glass.


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## joepro0000

Glass Finishers! I use regular mud, and pull tight on it for the 2th & 3rd coat. If you put a thick coat, your going to get bubbles. Scrap them off, and then pull tight.


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## EasyFlow

Haven't seen any pinholes since i started using Bondcrete, it's universal bonding & sealing agent that works great for all my insurance work that i do.
By mixing the Bondcrete with water to the manufactures specifications on the can, then brushing it on with a paint brush directly on the painted surface allowing time for the bondcrete to dry, then apply hot mud over the brushed on bondcrete followed by a topcoat with no pinholes.


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## smooth drywall

*bubbles over paint?*

hey i have a little way of fixing your problem with bubbles over paint apply ur mud as usual and depending on how thick or thin u prefer ur mud let it dry for 5 to 10 min then wipe again with knife or my fav. trowel hope this helps


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## Frankawitz

Ok maybe you might want to try this, remove the paint first by way of wallpaper stripper the 4" razor T handle one, I just did a kitchen ceiling that some body used Plaster Weld over paint failures, then they ran their mud, plain old joint compound with mesh tape.:whistling2: I scraped the whole kitchen ceiling took every square inch of paint off, then I primed the ceiling with Benjamin Moore's Block Filler, this stuff soaks into the plaster it doesn't lay on top. then I went and used M&H Ready Patch spackling, pole sand the ceiling then two finish coats paint.:thumbsup:


www.frankawitz.net


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## joepro0000

Frank I think thats too much work. Any if your doing touch-up after finishing a wall thats primed and painted, you wouldn't want to do that for every touch up or patch. Mud it, sanding it with a sponge if you need too. Sponges get everything out good.


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## joepro0000

BTW, nice website. Has lots of good pictures. You just need to organize the buttons at the top.


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## Frankawitz

Joe Thanks, I have had someone hack into my site and change pictures and text, I get tired of going and fixing things, I have lost all kinds of pictures, but thanks.
As for the repair you say is to much work, well I would rather peel the loose paint then go and paint and bubbles show up and then you have to scrape them. I have had to many ceiling and walls give up all the paint. I have scraped kitchens, living rooms, well you know cause of the pictures on my site. But I have a system to remove the paint and it works out better cause once all the paint is off the plaster all you have to do is spot the room out then prime and paint, but to each his own I guess. I just don't like to take chances on my repairs, cause I tell people they will last a 100 years.
But the thing about paint peeling is that when water breaks that bond between the plaster and oil base paints the paint will bubble when new coat of paint is applied, so that's the reason I scrape with the razor blade.


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## Apple24

use durabond for cripes sake no drywallers here if you havent fiquired this out by know ya kinda slow. you can put 7 coat of reg mud and still get blisters, but i am a plasterer as well so i guess i have you cats beat.


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## Whitey97

I might as well put my .02 in....

things that I have found that work

1. yes fast type setting muds.
2. "prime" it with gaurdz, (i think that's how it's spelt) it's a sealer a lot like oil paint
3. trowel your mud on, scrape it off, and trowel less than the area you did the 1st time. don't ask me why, or how, but it works to reduce bubbles.
4. deal with it.

I do like some of your idea's though guys, I like the scuffing the paint idea, sounds like it would work, however too much work. As far as getting DB out, I would rather not dic with pulling out enough for a tray full, to use a little bit. Honestly, try #3. I do it quite regularly, and I've been doing it that way for about 10 years


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## brdn_drywall

o.k.
i've found the solution to the air bubble problem put the mud on how ever you like and use whatever compound you feel comfortable with because they will come oh ya the little bastards will come.
when they do widen your eyes ass far as they will go and stare at them with your meanest face and i mean GLARE at em and think over and over in your head go away you little bastards go away.
now the real trick to this is not to say this out loud because they will not listen and if someone is around and hears you they will think your crazy (i know this because it has happened to me and i almost got committed because of it)
now i know what your all thinking but you really have to give it a try before you disclaim it.


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## brdn_drywall

oh ya i almost forgot this trick works well for people who do not want to pay you when your finished only don't chant go away you little bastards in you head think pay or you will really regret what i'm gonna do to you in 5 minutes you will usually have that check in 3 mins. haha i solved two threads with this trick.


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## Tim0282

Good one! Might work, nothing else does...


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## brdn_drywall

haha tim just thought i'd take a change from all the gloom and doom recession talk plus everyone's complaining and arguing gets tiresome, adding some humor in the mix seemed like a good idea.


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## Tim0282

Have to agree with you.


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## Whitey97

I forgot that approach! yeah I used to use that technique, however at the end of the day, I felt really worn out and head hurt!


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## Tim0282

Exercise that brain to eliminate those air bubbles!


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## rebel20

*air bubbles?*

first of all newbie in forum air bubbles do`'t have them here use Vario goes over paint with no bubbles


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## Muddauber

rebel20 said:


> first of all newbie in forum air bubbles do`'t have them here use Vario goes over paint with no bubbles



Wish I had some of that Vario stuff!


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## Whitey97

well you've got to be able to get it, look around for it dauber!


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## rebel20

Whitey97 said:


> well you've got to be able to get it, look around for it dauber!


 
Heard company in north carolina distributes it in USA


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## alltex

bob16 said:


> The worst air bubbles i ever ran into were solved completely by an additional skim coat (2 skim coats in total)
> 
> They really aren't that big of a problem. Just price for it when you bid the job.


iagree don,t over think it, skimm them out .


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## D's

I've recently started using the spray adhesive in a can that I use to glue plastic beads. Instead of sanding the painted area to be coated, I just give it a quick spray with the can of 3M. This ensures a good bond with the new mud and reduces bubbles too - works great when tying into existing painted walls, and is quicker than sanding or priming. For my following coats - I lay it on, wait a minute for any remaining bubbles to form, and then swipe again to work them out.

There going to happen no matter what - just work your technique so they don't take up too much time.

D's


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## croozer

best way i have found to deal with the bubbles is to get the 80 grit out and sand off the "water proof" sealing agent(paint), then use 20 minute compound mixed with dirty water on a dirty board and trowel occasionally for the 5 minutes it takes to set(harden). This technique works real well and leaves you a great base to top over, with absolutley no bubbles, but be sure to brush off any dust after sanding before applying compound


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## MuDD

When i get air bubbles i Trowel the mud in all different directions to work the mud into the pockets works for me


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## Bevelation

In principle, it's been mentioned already, but here's how I do it:

Apply mud, take it off. Apply mud again, leave it for 1-2 minutes before you work it into a skim coat. Repeat the process on different areas that need patch. I do sections of walls with 5-10 patches each at a time. Gets rid of 98% of the bubbles.


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## tvo

durabond does not bubble


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## carpentaper

Bevelation said:


> In principle, it's been mentioned already, but here's how I do it:
> 
> Apply mud, take it off. Apply mud again, leave it for 1-2 minutes before you work it into a skim coat. Repeat the process on different areas that need patch. I do sections of walls with 5-10 patches each at a time. Gets rid of 98% of the bubbles.


i just tried this on my last patches. works like a hot damn. my guess is the quick skim coat dries and gives you a porous surface that will not bubble the same way.


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## smoothbutt

Ive found that you can prime with drywall primer after your first skim coat and a little sanding. Then pull tight over surface to fill in holes. The drywall primer doesnt seem to bubble at all. I use Murco brand premium primer. hope this will help.


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## moore

MuDD said:


> When i get air bubbles i Trowel the mud in all different directions to work the mud into the pockets works for me


 YES that works. it takes just as long for hot mud to cure , as it does
a/p .without heat. it could take days for hot mud to set enough for next pass. with out bubbles . hot mud WILL NOT stick to bead / metal/ plastic/vinyl .


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## moore

tvo said:


> durabond does not bubble


b /s


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## cdwoodcox

I've always had the best luck with a 50/50 mix of plus 3 and 90 minute quickset . Some times just multiple coats are all you can do.


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## rebel20

moore said:


> YES that works. it takes just as long for hot mud to cure , as it does
> a/p .without heat. it could take days for hot mud to set enough for next pass. with out bubbles . hot mud WILL NOT stick to bead / metal/ plastic/vinyl .


Have you tried the Vario it does.


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## moore

rebel20 said:


> Have you tried the Vario it does.


yes i have rebel . you sent me 3 bags of 120. it does bond well to most anything. i mentioned it to one of my local supply houses. they said .
we will see what we can do. [that means no ].. i will order a pallet soon as
i can. it's the best for repair work. i gave one bag to another d/c , he likes
it as well.

so many products @ tools.... so little $$$..


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## rebel20

moore said:


> yes i have rebel . you sent me 3 bags of 120. it does bond well to most anything. i mentioned it to one of my local supply houses. they said .
> we will see what we can do. [that means no ].. i will order a pallet soon as
> i can. it's the best for repair work. i gave one bag to another d/c , he likes
> it as well.


 
I meant on the bead as well, I know you tried it.


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## stikman

Put a thin layer of reg. mud on, wipe off, then run like normal.


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## Tim0282

You can run the Vario mud right over paint. No bubbles. Not one. And sticks like crazy. Best prefill, bead, fixing anything bad a carpenter can do to us, mud. Good stuff. Ordered a pallet of the 11 pound bags. Using to run beads and all prefill. thought 180 bags would last a long time. Well, three jobs right in a row with more than a hundred beads each. That mud isn't going to last very long. Especially since we like it so good. Smooth, sets fast, and sticks to anything. I better get a job selling it for Rebel.


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## rebel20

Tim0282 said:


> You can run the Vario mud right over paint. No bubbles. Not one. And sticks like crazy. Best prefill, bead, fixing anything bad a carpenter can do to us, mud. Good stuff. Ordered a pallet of the 11 pound bags. Using to run beads and all prefill. thought 180 bags would last a long time. Well, three jobs right in a row with more than a hundred beads each. That mud isn't going to last very long. Especially since we like it so good. Smooth, sets fast, and sticks to anything. I better get a job selling it for Rebel.


Tim,
Thank you for the confirmation I have been saying this all along but who listens to me

Rebel


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## betterdrywall

The Vario is dayum good material,,But right now getting anything extra from a builder is tough,, I don't use any type of specialty mixes without getting extra for it. 
I often wonder about guys using Hot Mud , and other types of tape, and talking as if it is just normal taping method.. Right now it is very basic material for me.. anything else it is extra.. I don.t give a rats azz how much mud is dried and on the floor,,, I paid for it.. and they can get a flunky to scrape it up.


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## Tim0282

Since it shrinks less than other mud, you use less. First coat with Vario. You'll be surprised how much less it takes over it. Thus saving you millions of dollars. (slight exaggeration)


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## betterdrywall

Tim0282 said:


> You can run the Vario mud right over paint. No bubbles. Not one. And sticks like crazy. Best prefill, bead, fixing anything bad a carpenter can do to us, mud. Good stuff. Ordered a pallet of the 11 pound bags. Using to run beads and all prefill. thought 180 bags would last a long time. Well, three jobs right in a row with more than a hundred beads each. That mud isn't going to last very long. Especially since we like it so good. Smooth, sets fast, and sticks to anything. I better get a job selling it for Rebel.


Lately I have just been using my 6 and 8 on my bead work,,, Old way,,, No problems at all.. texture turns out great,, and nothing shows,, but I am running a full 6 and 8 ,, if I am using a 6 I wipe down with an 8,,, 8, I wipe down with 10,, saves material, faster to run out turns out clean with a very good amount of material that can be textured over, turns out nice and flat. Seems like I keep going back to the old methods everyday.


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## igorson

From my experience bubbles when you mix mud more or less time than needed. I can not say exactly for how long you should mix mud to avoid bubbles since i can determine it visually but you can experiment with this.
http://1drywall.com/painting.html


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## 2buckcanuck

Tim0282 said:


> You can run the Vario mud right over paint. No bubbles. Not one. And sticks like crazy. Best prefill, bead, fixing anything bad a carpenter can do to us, mud. Good stuff. Ordered a pallet of the 11 pound bags. Using to run beads and all prefill. thought 180 bags would last a long time. Well, three jobs right in a row with more than a hundred beads each. That mud isn't going to last very long. Especially since we like it so good. Smooth, sets fast, and sticks to anything. I better get a job selling it for Rebel.


Over paint with no bubbles ...........interesting
Could be the best punch list mud out there then.

Got my bag, just waiting for for something to try it on :yes:


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## Tim0282

Second coat over, smooth as glass! You're gonna love it! Don't ya hate it when somebody tells you that?


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## 2buckcanuck

Tim0282 said:


> Second coat over, smooth as glass! You're gonna love it! Don't ya hate it when somebody tells you that?


Yes I do hate it when someone tells me that. My 1st wife said that all the time to me


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## Tim0282

You usually know you are in trouble when they say it! But really this is very nice mud. I would be surprised if you didn't like it!


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## femich

*Tiny holes from air in drywall*

I am a homeowner that recently finished his basement. Upon putting together a punch list and walking the work I noticed tiny holes in the drywall mud all over the walls. I assume they are from air bubbles that burst. They are the size of a pin hole. From a professional drywalls perspective should these be fixed or accepted by the home owner? They are only noticeable within a foot or two of the wall.


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## gazman

If you have used a professional you should expect a professional job. Most pin holes are caused by moisture from the previous coat trying to escape. Fortunately it is not a difficult fix, the offending areas require a tight skim.


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## Engineer Mike

taper71 said:


> I think that you may just have to accept it as a fact of trade. I would certainly like to know a cure, but this topic has been the topic of discussion on three separate forums and I have yet to read one so far.


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## Engineer Mike

Hi taper71, 
As a Maintanence person, I could go for long periods w/o using my drywall tools. I have experienced this myself and know the pitfalls. I have a question for you. When applying mud, I have noticed that the mud gets dry and settling. Is the air bubbles because the mix is just dry enough to not soak in. I have to add a slight about of water and mix. In Cali, the climate is dry. Also when muddying, I reuse the mud I applied, wiped it off and put back in the trough. Do I lose the bonding integrity as well?


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## Kingofheartsdrywall

sand the paint before you start taping. add a bit of soap. use cgc grey box and you will get very minimal bubbles. your all welcome.


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## Shelwyn

There are special chemical bonding agents you can apply to old paint. Ask your local supply warehouse for a name. They're annoying you need to roll it onto the paint and apply the joint compound to the paint while the chemical is still wet and it'll bond them together. It prevents peeling and bubbles but it does add material and labor cost. 

Obviously this is a cheaper option to demoing a place and applying new compound so if you've got a cheap landlord who wants you to mud right over the paint it's another cheap option for you to offer.


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## Pinkalink

I've tried many different solutions in the past, ultimately you just got to touch up your mud work after you prime. Don't add anything other than water to your mud. It doesn't help.


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## Muddobber

Drywall1 said:


> OK guys, me being the punchlist guy now I need a difinitive answer... how do I keep them damn air bubbles from causing me to put on 4-5 coats. I know why they come..so we don't need to go there.
> 
> Tried soap...no dice. Used brown bag durabond this am on a remodel project. We will see tomorrow.
> 
> If patch only needs one light skim its OK but if more coats are needed its bubble city.
> 
> 
> Used to just be me and one guy doing all the work, now I bid, patch and run around a lot. Man things were easier back in the day!
> 
> Nate





Drywall1 said:


> OK guys, me being the punchlist guy now I need a difinitive answer... how do I keep them damn air bubbles from causing me to put on 4-5 coats. I know why they come..so we don't need to go there.
> 
> Tried soap...no dice. Used brown bag durabond this am on a remodel project. We will see tomorrow.
> 
> If patch only needs one light skim its OK but if more coats are needed its bubble city.
> 
> 
> Used to just be me and one guy doing all the work, now I bid, patch and run around a lot. Man things were easier back in the day!
> 
> Nate


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