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Discussion Starter · #1 ·
I'm getting small bubbles (about the size of a pen tip or just a bit bigger) in a few areas in a freshly painted wall in a bathroom remodel. It was an existing wall that was primed with BIN, skim coated with general purpose drywall mud, primed with drywall primer and top coated with Sherwin Williams Super Paint. I applied the first coat and there weren't any problems with bubbling. A few days later, the bubbles appeared as I rolled the paint. After the paint bubbles dried, I scraped them down and it went down to the drywall/primer layer. The only thing that happened in-between coats was the plumber sweated on a toilet stop in the area (small toilet alcove).

Any thoughts on why this is happening and how to remedy?
 

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Discussion Starter · #4 ·
The drywall was done a.couple.ofweeks prior to paint. I think the primer was Kilz drywall primer from Lowes.
 

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If it was pva primer that was a mistake.
That's what I used to think. Now I keep being told it is the way to go.

Still don't know.

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Discussion Starter · #7 ·
I also thought PVA was the way to go. I had read that it nuetrilzes the PH in the drywall mud or something like that.

This is the first time this has happened to me using PVA primers (usually different brands though). It's also just isolated to a few spots on the wall, not all over.
 

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That's what I used to think. Now I keep being told it is the way to go.

Still don't know.

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Why do you think pva is so cheap it's crap on drywall and worse on the mud. It never has been the way to go it's not worth cutting cost on primer. I'd rather use cheap paint over more expensive primer.
 

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Here is what I think, there is some underlying contaminant, we come along, do our thing thinking we have done everything right. We apply a coat of paint and as it dries it interacts with said contaminant, which may be many layers deep, and causes a bubble as it tries to off gas. Sometimes the first coat we put on is fine and the second coat causes the bubble.
I do not believe we are doing anything wrong, it is an underlying issue that we can not see.

Very occasionally they go back down, but usually don’t.
I do not believe you are doing anything wrong.
We have a standard fix, scrape bubble, prime, mud, sand, prime, paint. Yep it sucks.
We have encountered many bubbles on a a wall after rolling on the second coat, yet the first coat was fine.
 

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Forgot to add, I avoid PVA primers and any other cheap primers, use the best quality primers, but I do not think that is your issue.
PVA has poor adhesion issues down the road.
 

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Discussion Starter · #11 ·
Here is what I think, there is some underlying contaminant, we come along, do our thing thinking we have done everything right. We apply a coat of paint and as it dries it interacts with said contaminant, which may be many layers deep, and causes a bubble as it tries to off gas. Sometimes the first coat we put on is fine and the second coat causes the bubble.
I do not believe we are doing anything wrong, it is an underlying issue that we can not see.

Very occasionally they go back down, but usually don’t.
I do not believe you are doing anything wrong.
We have a standard fix, scrape bubble, prime, mud, sand, prime, paint. Yep it sucks.
We have encountered many bubbles on a a wall after rolling on the second coat, yet the first coat was fine.

Forgot to add, I avoid PVA primers and any other cheap primers, use the best quality primers, but I do not think that is your issue.
PVA has poor adhesion issues down the road.
Thanks for the response and suggestions on how to fix.

Any reco's on primer over bare drywall for the future? Any other tips to avoid this problem? Is it worth it to do a quick scrub with a TSP solution, or is that overkill?
 

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If it's limited to where the plumber did his sweating, I'd guess it's from the acid flux getting evaporated and condensing on the wall.

Unfortunately, there are a number of ways you can get bubbles, so no way to tell for sure.

I don't use any kilz product except kilz original, and only in special situations.

I dropped PVA drywall primers a long time ago. Topcoat adhesion issues and too prone to flashing. I use primer / sealers, mostly Zinnser. Pick any, they all work.
 

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Thanks for the response and suggestions on how to fix.

Any reco's on primer over bare drywall for the future? Any other tips to avoid this problem? Is it worth it to do a quick scrub with a TSP solution, or is that overkill?
Use Glidden gripper. As I’ve stated before, you can’t pull that stuff off w/a dozer

Mike
 

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I also use gripper. I noticed that the label has changed but I never read it so I didn’t know that PPG bought Glidden.
nicko.
 

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Yep. It isn't the same at all. Now they say you need to prep shiney surfaces and metal.

That was the whole reason to use it. It was a magic primer. Solved a lot of issues.

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I've been using the Insulex products exclusively. Aqualock is my go to. (Latex) Prime lock (oil)for tougher situations.

Stix for extra adhesion. It does not stain block, but will adhere to formica, glass, tile ect. I painted some melamine cabinets starting with stix.

They claim you can go over crayon and lipstick with Aqua and Prime lock. Low voc as well. Sherwin in Ct. Does not offer an oil base anymore.

I doubt the acid core condensation on the wall is the source of your problem. Maybe if the plumber slashed some or wiped his finger with flux on the wall, but I would think you would have seen that before and wiped it off.
PVA primer is dirt cheap making it economical. I don't use it.

Reminds me last month I repainted a rec room for a customer. It was only going to be half the room where the drywall was patched. But by the time I got to paint she decided to do the whole room, and what ever color I want. So I primed everything.
Went one coat Aura went to do second coat, and the there were two spots, two to three inches, dark brown that came through the paint and didn't show before or after the prime.
I spot treated the two spots with oil. First one paint covered right away.
The second one I had to prime a second time. Before the paint would cover.
There had to be something under the layers of the old paint. Almost thought I was going to have to cut the spots out at one point...

You just never know what's under there. If I used PrimeLock first it probably would have never come up. But it's not my go to primer.
 

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I have never used primer on drywall. Quality paint over drywall and mud without any primer. In my own house I re-did the drywalls in 2 of my basement rooms due to water damage and painted right on top of the new drywalls with Behr paint which most professional painter call it crap paint, this was nearly 18 years ago. The paint still looks as good as day one. No discoloration, no peeling, no nothing. I would like to know from some professional painters why a primer is needed? is it just to reduce the number of layers of paint?
 

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This depends a lot on what you're covering, sheen, and lighting.

Most professional painters use a system that always works. If the surface isn't adequately sealed, you will definitely have sheen differences. Add critical lighting, and it can very noticeable. With regular paint, you may have to 4 coat. Beth's answer to this with it's original paint and orimer in 1 was to make it thigh so you out in thick coats. Thick coats of any paint gives a noticeably different surface.

A lot of 100% acrylic paints have good adhesion.
 

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I have never used primer on drywall. Quality paint over drywall and mud without any primer. In my own house I re-did the drywalls in 2 of my basement rooms due to water damage and painted right on top of the new drywalls with Behr paint which most professional painter call it crap paint, this was nearly 18 years ago. The paint still looks as good as day one. No discoloration, no peeling, no nothing. I would like to know from some professional painters why a primer is needed? is it just to reduce the number of layers of paint?
If you use a good primer it prevents a lot of things. How many unprimed walls have you seen that you could see the butt joints or nail runs in? Stairwells, well lit foyers, hallways etc. Years ago worked for a builder
& his famous saying was: you really can’t tell unless the light hits it just right. How unprofessional can you be? For the penny pinchers a good primer &~~ topcoat is eons better than zilch primer. Oh, & Behr is crap. Helper used their “primer & paint in 1” whatever that chits called on some 20’ tall fluted collums in a historic district that slipped by me. Collums were completely stripped & left alone 3 days before he painted. Chit checked like an all night poker game. You see where this is going? Yea another didn’t even make wages

Mike
 
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