# every now and again bubbles



## ltd (Nov 18, 2010)

ever have this happen i use sheetrock 20 /or 45set to do all my big patches . i let patches dry then i sand smooth dust off then prime with quality flat latex thats what sheetrock 20 set calls for then i paint it . no problems . but when i put 2 coat their are some bubbles about the size of a mm some times they shrink most time i stick pin in bubble and push back and cross my fingers. this happens with flat/ satin ps all dry times are proper and surface is clean it also does it with pro block and gripper primer thanks


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## Lambrecht (Feb 8, 2010)

Sounds like a humidity/moisture problem. Are you in an area with high humidity and are you letting your your patched areas dry thoroughly? Are the air bubbles on the whole wall or just on the patched areas?


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## ROOMINADAY (Mar 20, 2009)

Make sure you neutralize the PH of the fast set/ hot mud with a primer that lists it as a property. 1,2,3 - Fresh Start -Seal Grip, etc..There is the possibility that the mud is still wet, looks dry on the surface but still creating it's chemical reaction. 


We have also found that if we drive coats on really fast, it used to happen more often. It was like it is was re-wetting the patch.....We neutralize all patches now with a specialty primer, no issues. We find the higher end acrylics don't do this as often so any primer seems to work. 

We use Aura mostly in all repaints and we just coat straight over fast set with no issues. I have primed "set" not dry patches with 123/ Coverstain, painted 2 coats as fast as they would dry (even just straight Aura and have had no bubbles......is it right..... nope!


Now....I have never had bubbles in NC even with all 3 coats fast set...Only on previously painted surfaces........


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## straight_lines (Oct 17, 2007)

Lambrecht said:


> Sounds like a humidity/moisture problem. Are you in an area with high humidity and are you letting your your patched areas dry thoroughly? Are the air bubbles on the whole wall or just on the patched areas?


 It is a moisture problem. I have had this happen many times in very humid homes that have a wet crawlspace. Moisture wicks up the wall and reactivates the mud.


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## daArch (Mar 15, 2008)

adhesion problems can be caused by many things. Moisture and dust are the two primary culprits.

How long are you allowing the hot mud to cure. Setting in 20 or 45 minutes is one thing, but the patches are not yet dry, especially if they are thick.

You say you sand and dust. How do you dust? With just a brush? or a vac? Run your bare hand over the patch and see if your hand is dustless. If not, try a swifter or a slightly damp micro-fiber cloth. 

You didn't mention it, but sometimes some people mix drying type with setting type muds (pre-mix joint compound with Dura-bond). This mixture has been known to raise the pH to ungodly levels. If you do do it, don't do it anymore. 

Personally, if I were still painting, I would take advantage of the low prices of today's moisture meters. $40 ain't bad for the insurance and assurance it buys.


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## ltd (Nov 18, 2010)

*thanks guys 4 the replies*

im with you on all comments. i use2 rush dry times but im pretty much by the book at least pretty much. drying dusting pirming . ok one thing that seems 2 help is when i prime patch i will roll it a couple times with firm pressure to mix primer with patch this way primer and patch are one. you have 2 be careful not 2 lift the patch im talking maybe 3 passes tops then move on. this only happens maybe 3 times a year and i can most times burst bubbles and work them back / but it still su ks. thanks again guys


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## JHill (May 13, 2010)

ltd said:


> ever have this happen i use sheetrock 20 /or 45set to do all my big patches . i let patches dry then i sand smooth dust off then prime with quality flat latex thats what sheetrock 20 set calls for then i paint it . no problems . but when i put 2 coat their are some bubbles about the size of a mm some times they shrink most time i stick pin in bubble and push back and cross my fingers. this happens with flat/ satin ps all dry times are proper and surface is clean it also does it with pro block and gripper primer thanks


 
If your patching over existing paint there could be anything on the walls, 
cleaning products, nicotene, etc. Which we have found to bubble on us also. Prime your patches with a primer/sealer instead of flat paint.


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## plainpainter (Nov 6, 2007)

hot muds are no different than veneer plasters in terms of waiting time before applying a primer. The stuff is HOT!!!! And hotness has nothing to do with the moisture involved. I have several methods of dealing with this, none of which I will share online anymore in an open forum.


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## [email protected] (Mar 1, 2008)

[Just had this problem. I talk with my plaster about it. THis was a old plastered house. He see it on plaster house every so often and all is avises to use Bin or a good oil primer. At the same time they are big Bin fans. Witch I am to. I just didn't on this job. But did after my talk for the second fase of repairs. 
David


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## ltd (Nov 18, 2010)

*yes sir re jim bob*



plainpainter said:


> hot muds are no different than veneer plasters in terms of waiting time before applying a primer. The stuff is HOT!!!! And hotness has nothing to do with the moisture involved. I have several methods of dealing with this, none of which I will share online anymore in an open forum.


 when you say its no different than a veneer plaster im thinking to use a masonry primer . I'm i close to seizing the pebble?


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## plainpainter (Nov 6, 2007)

ltd said:


> when you say its no different than a veneer plaster im thinking to use a masonry primer . I'm i close to seizing the pebble?


Now you are using your noggin' - now you should start experimenting and see where it takes you. 80% of what I know is my willingness to experiment with different products and trying to understand the root cause of a problem. 

There's a far easier solution to it though. Again, trade secrets that won't get revealed online.


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## NEPS.US (Feb 6, 2008)

plainpainter said:


> There's a far easier solution to it though. Again, trade secrets that won't get revealed online.


 
You better carry around a cyanide pill around just incase any painting contractor in the Boston area decides to kidnap you and torture you for information. You could be the Jack Bauer or paint!


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## IL_Painter (Dec 4, 2010)

Don't use hot mud anymore and it wont happen. I used to use 20 and 90 all the time but have since stopped because it's just too soft.


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## Capt-sheetrock (Feb 10, 2008)

I'd tell ya what was happening here, but since Plain won't share anything,,,, I guess I better not too !! I didn't think I was that cool, till I read Plains post.

But,, I bet I know an easier and better way than he does,,,,,, too bad we will never know.


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## saveonpainting (Mar 17, 2010)

*Save on Painting Co. | Vancouver BC Painting Company | reply:*

I agree with most replys. to me this might appear not to be a problem of application, but the method used.

*1: *Air bubbles can appear in patched mud, if it is not dried properly *i.e*. if it is _"speed dried"_ the surface may be dry enough to sand whill the inner part still _"wet"_ will produce bubbles as it dries completely.

*2:* In certain applications latex based paints will bubble in exterior situations where the sun is blistering hot..._and does just that!_

From the way your describing the bubbles sounds to me like it might the *1st* problem.
*Solution:* Slow down, pace yourself, keep it by the book. :thumbup:

Save on Painting Co. Vancouver BC


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## SCpaintguy (Jan 5, 2011)

Bubbling like you described sounds like a surface contaminant or reactivation of what is underneath, maybe a pH problem. Litmus paper can answer the pH question, contaminant comes from how you clean or other environmental factors(how much time in between patch and paint, any reddy heaters around, etc.) It doesn't take much to cause a reaction. If it is pH, there are several pH friendly primers on the market. Dedicated primers are better due to a higher resin content than paint, which do a better job of sealing. Hope this helps, good luck.


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