# Explain why this guy's caulk has blisters!



## stelzerpaintinginc. (May 9, 2012)

House is about 6 yrs old. The sider on the job ended up breaking his back and his brother finished the job. Caulking looks sad. Most of it looks like OSI topped with DAP. Little bubbles/blisters are on the caulk on every side of the home, but most prominent on every interior corner all the way around the home, as well as the bottom 10' on each exterior corner. Not prevalent around windows or doors. House is on a hill and gets beat by the weather. When I popped a few bubbles, no liquid was present. I've seen some bubbles in caulk before, but never to this degree. 

Sorry for the less than perfect pics, but it was raining hard.



*Question: What's Causing This?*

*My Best Guesses: 
-Initial caulk either applied when it was too hot, too cold or too wet?
-Potential puncture in backer rods causing off-gassing?
-Caulking over-tooled or incorrectly applied?
-Potential moisture/vapor trying to escape?
-Cheap or old caulk?
-The Government?*

As you can see, I got enough guesses. Really looking for someone who has seen this particular situation and came to a definitive conclusion as to the cause. Thanks in advance for any insight.


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## Seth The Painter (Jun 24, 2015)

Yes I've had this happen to me before actually. It's because the siding was to hot when it was applied. Cut it out and start fresh. Just cut the areas where it's blistering and you should be ok. Hope this helps.


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## journeymanPainter (Feb 26, 2014)

I was going to say heat as well. 

On a side note, why is it only painters can caulk?


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## Seth The Painter (Jun 24, 2015)

journeymanPainter said:


> I was going to say heat as well.
> 
> On a side note, why is it only painters can caulk?


It's because we are the one finishing no body else cares. Sometimes if I see a carpenter that I know can't caulk I will distract him and my other guy takes the gun. It's pretty funny. I tell the gcs don't let anyone caulk. I prefer doing it myself.


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## stelzerpaintinginc. (May 9, 2012)

This one is kinda hard to pinpoint for me, since I can't even assume the job was done professionally. Most of the siding was installed by the original siding contractor, but none of the caulking was done by him. That opens the door for any number of potential reasons for this happening that I wouldn't normally have to consider.


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## racx (May 2, 2015)

I'm going to say Seth is right but closed cell backer rod does cause out gassing. I see similar in commercial work all the time.


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## Jmayspaint (Mar 26, 2013)

I see bubbles in caulking like that sometimes when it's a second, or third time around caulking job. If an old bead of caulk was partially removed or there is some other inconsistency, voids in the crack can cause bubbles in the new bead. Haven't see it that extreme, so it may be something different than what I'm thinking of. 

What I think happens is air pockets behind the bead push the caulk out. A few times I've seen it happen when the bead was still wet and tried to wipe it to push it back in, and it pops back out in a couple minutes. Maybe has something to do with the drying process (evaporation) of the caulk causing increased pressure in those air pockets, and pushing the caulk out. 

I've seen it happen with backer rod too, but at the time I chalked it up to inconsistent application of the rod that left air behind parts of the bead.


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## MIZZOU (Nov 18, 2012)

Solely based on your close up pictures Id guess that application is to blame. Way to much caulking and improper tooling as evident by those disgusting ridges.


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## Wildbill7145 (Apr 30, 2014)

I'm going with the application in direct sunlight on a hot surface answer. I've seen that happen with latex.

It's even worse when you're using thermoplastic sealant. Microbubbles throughout the whole thing. Millions of them.


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## GR8painter (Dec 18, 2014)

Explain why this guy's caulk has blisters!

Uhh...cuz.he's been hanging out with too many skanks from the club.:clap:


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## ReNt A PaInTeR (Dec 28, 2008)

It was too hot when it was applied.


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## Jmayspaint (Mar 26, 2013)

MIZZOU said:


> Solely based on your close up pictures Id guess that application is to blame. Way to much caulking and improper tooling as evident by those disgusting ridges.




Yeah, but looking at the farther back pic it seems like the extreme ridge is localized at the joint where the bubbles are. The rest of the bead looks solid, if buggery and a little larger than should be necessary.


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## I paint paint (May 4, 2014)

Jmayspaint said:


> I see bubbles in caulking like that sometimes when it's a second, or third time around caulking job. If an old bead of caulk was partially removed or there is some other inconsistency, voids in the crack can cause bubbles in the new bead. Haven't see it that extreme, so it may be something different than what I'm thinking of.
> 
> What I think happens is air pockets behind the bead push the caulk out. A few times I've seen it happen when the bead was still wet and tried to wipe it to push it back in, and it pops back out in a couple minutes. Maybe has something to do with the drying process (evaporation) of the caulk causing increased pressure in those air pockets, and pushing the caulk out.
> 
> I've seen it happen with backer rod too, but at the time I chalked it up to inconsistent application of the rod that left air behind parts of the bead.


This gets my vote. Happens all the time to me with polyurethane sealants.

Moisture also causes bubbling with polys, whether from atmosphere or from wet tooling.


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## Epoxy Pro (Oct 7, 2012)

I tell all contractors we run into to leave the caulking gun alone. Most never wipe, they run a bead and leave it. I have walked off of jobs the carpenters caulked on.


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## stelzerpaintinginc. (May 9, 2012)

Thanks to everyone that chimed in. Although it's pretty much impossible to say for sure what caused it, I think it's pretty much in agreement that the bad caulking needs to be cut out before applying new stuff. 

I submitted the bid and told him that I'd be happy to do the job...next Spring.


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## RH (Sep 7, 2010)

I hope all of you appreciate the fact that the inner 14 year old in me wanted to make all sorts of inappropriate comments about the guy not using proper protection, or hooking up with the wrong type of partners, but I didn't. :no:


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## stelzerpaintinginc. (May 9, 2012)

RH said:


> I hope all of you appreciate the fact that the inner 14 year old in me wanted to make all sorts of inappropriate comments about the guy not using proper protection, or hooking up with the wrong type of partners, but I didn't. :no:



I needed an attention-grabbing headline that would entice without raising the eyebrows of mods/admins. It's a fine line.


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