# cracked caulking



## bluegrassdan (May 8, 2015)

I have been using Dap Dynaflex for a couple years after finding Alex Plus had stopped working for me. The last 2 jobs I am finding the paint is cracking even after the caulk has dried overnight. Has the Dynaflex changed lately? Or maybe I got a frozen batch when delivered. 

I don't have much choice around here. Maybe some Mono products.


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## SS_painting (Jan 11, 2020)

Mono shrinks like crazy, I don't recommend it.
Dynaflex is the best, maybe just a bad batch 
Try the quick dry Alex plus, you'll have to do 2 passes in some areas, but well work it

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## bluegrassdan (May 8, 2015)

These last 2 jobs were heated with a heat pump. Maybe a humidity problem and the caulking is not completely drying overnight.


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## SS_painting (Jan 11, 2020)

bluegrassdan said:


> These last 2 jobs were heated with a heat pump. Maybe a humidity problem and the caulking is not completely drying overnight.


That's your problem.
Buy a couple portable heaters, and let them run throughout the night.
The one below is the one I recommend









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## bluegrassdan (May 8, 2015)

there is a humidity setting on the heat pump. Maybe that will help


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## Wildbill7145 (Apr 30, 2014)

SS_painting said:


> That's your problem.
> Buy a couple portable heaters, and let them run throughout the night.
> The one below is the one I recommend
> 
> ...


Not sure I'd let one of those portable heaters run over night unless the house is occupied and the owner guarantees that he'd be checking on them. Even then it wouldn't be me setting them up and leaving them running. Not a chance. Already been a few houses burned to the ground around here this year from those things being left on all night.


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## SS_painting (Jan 11, 2020)

Wildbill7145 said:


> Not sure I'd let one of those portable heaters run over night unless the house is occupied and the owner guarantees that he'd be checking on them. Even then it wouldn't be me setting them up and leaving them running. Not a chance. Already been a few houses burned to the ground around here this year from those things being left on all night.


From these ones?
Wow. The whole reason I recommend it is because of how safe the design looks. 

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## Wildbill7145 (Apr 30, 2014)

SS_painting said:


> From these ones?
> Wow. The whole reason I recommend it is because of how safe the design looks.
> 
> Sent from my SM-G950W using Tapatalk



Not sure exactly which ones were the cause around here. Most of the ones that use sealed oil radiators have 'tip over' technology that shuts them off. My little 'barrel heater' has some form of overheat protection that shuts it down. I just couldn't leave anything temporarily generating heat from an element overnight unless I was there to keep an eye on it.


Hard to advocate leaving one on without knowing what type of heaters people have and what condition they're in. Guess you can't protect people from themselves all the time though.


I do like the ones you've got in that picture though. Fond memories of parking myself in front of one when we'd go camping as a kid during the fall.



A friend of mine just had her oil furnace go wild the other night. Blew up the duct work and part of the chimney. She described it as an explosion that shook the house. Nothing's perfect I guess.


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## jr.sr. painting (Dec 6, 2013)

Just buy some of the variable speed blower/fans they work great to dry paint,mud,caulk, wet tarps or anything else. Also no fire hazard leaving them on overnight.


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## juanvaldez (Sep 7, 2019)

That presto heater works great! I use one inside my portable dry room(ezup tent) when doing cabinet doors. It makes a super loud buzz sound if barely moved off the bottom sensor. 
But yeah, would never leave a heater on unattended overnight no matter what kind. 


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## juanvaldez (Sep 7, 2019)

Also I’ve been using the quick dry either dap latex or S-W 1050 QD. Both work well. You have to work fast with them though as they skin over quickly after application. 


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## bluegrassdan (May 8, 2015)

Any info on Dap Flex


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## bluegrassdan (May 8, 2015)

I tried it a couple times and it wouldn't dry even over night


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## SS_painting (Jan 11, 2020)

Wildbill7145 said:


> Not sure exactly which ones were the cause around here. Most of the ones that use sealed oil radiators have 'tip over' technology that shuts them off. My little 'barrel heater' has some form of overheat protection that shuts it down. I just couldn't leave anything temporarily generating heat from an element overnight unless I was there to keep an eye on it.
> 
> 
> Hard to advocate leaving one on without knowing what type of heaters people have and what condition they're in. Guess you can't protect people from themselves all the time though.
> ...


I just used the one pictured the other week, I went to move it, and it started making a loud annoying buzzing sound, and started shutting off by itself, and that was just the slightest angle.

I highly recommend this unit now, just be aware of what your placing it on. 

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## Holland (Feb 18, 2011)

SS_painting said:


> Mono shrinks like crazy, I don't recommend it.
> Dynaflex is the best, maybe just a bad batch
> Try the quick dry Alex plus, you'll have to do 2 passes in some areas, but well work it
> 
> Sent from my SM-G950W using Tapatalk


I get a ton of cracking with Alex Plus "quick-dry". 
I prefer Alex Plus (standard) caulk, and let dry overnight. Alex had a problem with bubbles in almost all of their caulk a few years ago (when they switched to a new machine that filled the tubes) but they seemed to have fixed the problem.


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## bluegrassdan (May 8, 2015)

I always used Alex plus until a couple years ago when on a couple jobs it completely let go after only a few weeks. 

On another note does clear caulk shrink more than white? Been using Dynaflex 230 which goes on white and dries clear.


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## SS_painting (Jan 11, 2020)

bluegrassdan said:


> I always used Alex plus until a couple years ago when on a couple jobs it completely let go after only a few weeks.
> 
> 
> 
> On another note does clear caulk shrink more than white? Been using Dynaflex 230 which goes on white and dries clear.


I find it does, and definitely takes a lot longer to dry

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## Joe67 (Aug 12, 2016)

bluegrassdan said:


> I always used Alex plus until a couple years ago when on a couple jobs it completely let go after only a few weeks.
> 
> On another note does clear caulk shrink more than white? Been using Dynaflex 230 which goes on white and dries clear.



I am always in the Dynaflex 230, but almost always the white. 



I can't say whether I've noticed the clear shrinking more or less, but if I've had cracking problems it's only with the clear.


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## finishesbykevyn (Apr 14, 2010)

Is it your ceiling paint cracking, or your trim paint? I find sometimes, especially cheaper ceiling paints can't keep up with the flexibility of dynaflex..
works great on crown moulding though, but should probably be sprayed with trim paint rather than ceiling paint.


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## bluegrassdan (May 8, 2015)

It was ceiling and trim paint. I am blaming it on the mini split heat pumps that were present in the jobs that the caulking cracked.


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## finishesbykevyn (Apr 14, 2010)

bluegrassdan said:


> It was ceiling and trim paint. I am blaming it on the mini split heat pumps that were present in the jobs that the caulking cracked.


You originally said your paint cracked on the caulking. So did the caulking crack or your paint? There would be signifacant differences in remedies.


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## bluegrassdan (May 8, 2015)

the paint cracked


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## Woodco (Nov 19, 2016)

It might not even be the caulking. It could be expansion contraction with the walls themselves.

It could also be the paint. Cheaper flats are way more crack prone.

And yes, clear caulking shrinks big time. I've been trying to find a clear that isnt so runny. Big stretch is the closest thing.


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## JohnDoor (Apr 7, 2020)

Woodco said:


> It might not even be the caulking. It could be expansion contraction with the walls themselves.
> 
> It could also be the paint. Cheaper flats are way more crack prone.
> 
> And yes, clear caulking shrinks big time. I've been trying to find a clear that isnt so runny. Big stretch is the closest thing.


Ditto. For small cracks I've had luck with LifeCalk from Boat Life. It's for marine/boat purposes, can set up underwater and remains flexible. Not suitable for regular caulking but might help for small cracks and/or repairs.


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## minneapolispainting (Apr 15, 2020)

What's the best way to keep caulking from cracking?


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## Joe67 (Aug 12, 2016)

minneapolispainting said:


> What's the best way to keep caulking from cracking?



Ok, well this thread was really about the paint applied over caulk cracking rather than the caulk itself cracking.


But the best way is to use high quality caulk (I'm sold on Dynaflex 230), and always know that the gaps do need to be filled rather than just covered by a film.


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## Woodco (Nov 19, 2016)

minneapolispainting said:


> What's the best way to keep caulking from cracking?


Also, use a better quality paint that wont crack as easily.


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## finishesbykevyn (Apr 14, 2010)

Woodco said:


> Also, use a better quality paint that wont crack as easily.


It makes total sense. If your using a super flexible high quality caulking(Which is good so your caulking doesn't crack) and then spraying a cheap not as flexible ceiling paint over it, it's probably going to crack. Best bet is to
A: Not put the caulking on quite as thick
B: Paint/Spray your crowns with Higher quality acrylic paint.


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## minneapolispainting (Apr 15, 2020)

*Ceiling Paint*

What ceiling paint would you recommend that's more flexible and doesn't tend to crack?


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## ParamountPaint (Aug 25, 2016)

minneapolispainting said:


> What ceiling paint would you recommend that's more flexible and doesn't tend to crack?


I think the attributes that make ceiling paint "good" are incompatible with flexibility. The higher end flats aren't really flat, so then you've got issues with sheen, lap marks and general crappy drywall finishes, which would otherwise be hidden by clay-heavy ceiling paint.

Good finish-carpentry workmanship, which follows good framing and good drywall is the best answer, but we rarely have control over such things. If things are installed tight, flat, plumb and true, only the smallest bead of caulking should be required. Then you have the climate control issue as well. The tightest workmanship is not going to last through large temperature and humidity swings.

It's a vexing issue.


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