Painting a new room, recently primed. The paint in all of the inside corners cracks as it dries. Second coat isn't completely hiding it. Any suggestions as to why its cracking and what to do about it? Sherwin Williams paint, decent brush, not applied on too light or too heavy... haven't run into this before.

 

Was the drywall mud good and dry? or were the corners caulked?

Sanding the inside edge and another coat of paint may help.

 

Yup, nice and dry, best looking corners I've done to date - mudded not caulked. One thing I should mention - after priming they looked great, but I left them for a month before I painted and the primer was cracked only a little bit in a few places, not as much as with the paint now.

It's only right in the corner where the paint is bulking.

 

Assuming you are cutting in each wall seperately, I suspect the paint on the 1st wall is partially dry when more paint was applied by cutting in the 2nd wall. The result is the paint underneath doesn't get to dry at the proper rate = the cracks.

No big deal - a light sanding and another coat of paint should fix it.

 

What I usually do is brush vertically into the corner, and then on the left side wall and then on the right side wall, working my way down the wall while the paint is still wet and smooth flowing through the brush. Done this many times without issue... is there something wrong with my technique?

I started sanding the corners lightly with a fine crisp 90 degree angled sanding sponge, looks like it will probably take 20 minutes to do the whole 400sq ft area, no big deal. They look smooth and the cracks are coming out, hopefully they won't reappear when coated again. Will keep you posted, should be able to get to it tonight.

 

That's how I cut in the corners. Sometimes things just happen.

 

I'm losing the battle here. I sanded all of the corners to the point where I could mostly see all of the cracks completely gone. I tried applying the paint the same way I always have, looks great, dries, cracked just as bad. I noticed while it was drying that small little black bubbles were forming and thats where the cracks showed up. That indicated to me that this paint does not like to be bulked up at all. So I tried painting in the corners with an almost dry brush, just enough to get some in the corner, and even this cracks but not as much.

 

I decided to try another technique. Instead of painting vertical inside the corner which causes too much paint to bulk up, I decide to paint with the brush horizontal, with less paint on the brush. I covered the same area that took me 1.5 hours before in about 5 minutes, no bulk, and no cracks showing up yet.... will keep posted.

 

Which SWP paint are you using?

 

SW Promar 200, flat latex.

 

So I phoned SW and explained the situation. He said its not common for this to happen - figured it was a mudding issue. I explained to him that I used the same mud, same tools, same tape, same technique, and the same SW primer with cheap box store paint in my closet where I had to remove drywall for a plumbing repair, and no cracking occurred in the corners. He mixed me up a can of contractor(lower) grade Quali-kote paint for free and said to try it in the corners. Most of the cracks have disappeared after I brushed horizontally last night, we'll see how it looks in a few days.......... sigh

 

I've almost always use promar 200 on new construction and don't remember ever having that problem

It's been my experience that the different grades don't always color the same and may have slight sheen variations - hope the different paint matches ok. If it doesn't you might try thinning the 200 a little and see if that takes care of the problem.

 

I've been forced to move on to other things for now - door installations, carpet ordering, garage and fence work, so it may be a bit before I get to the touch up stage. Fortunately after coating the corners the third time as mentioned above, I can barely see any cracking after a few days of drying. Nothing like it was previously....


Thanks as usual marksr.

 

How old was the paint and primer? I just finished a closet and I had some primer and paint that sat in my garage through the winter but decided to use it anyway since its a closet. Well after a few days I noticed minor cracks in the corners. I think my paint went bad. maybe your problem, too since the new paint shows no signs of cracking.

John

 

John,
If your paint was subjected to freezing temps - it's no good. Paint that has froze will be a lot thicker than normal [even after it's thawwed out] and won't adhere well to the wall

 

I bought it and used it right away(within a couple of days) stored inside at room temp, don't know what happened to it before I bought it. It actually seemed a bit thinner than other latex's I've used.

 

I'm sure your paint is fine, John had an entirely different problem.

 

Both were actually very thin and watery-like. I buy F&H paint and pretty much one coat is all that's needed but not this time. I had put on 3 coats of primer and about 2-3 coats of paint and the only problem is in the corners with slight cracking. Only noticeable when your staring at the wall looking for problems Once I opened and mixed them I knew they were prob not good but since its a closet I used them anyway.

John

 

Was there some thick "goo" at that bottom of the can?
What's F&H paint?

 

No thick goo. Just runny

F&H - Finnaren & Haley

 

I'm moments away from finishing my basement so I decided to use the lower grade stuff in the corners. It's been about 6 hours and it still looks way darker than the rest.... I have a piss amount left of the original paint so lets hope it dries and blends.

 

marksr, you were right. The sheen was different. I had just enough paint from the original mix to go over it again. Won't know for a few days whether or not using the lower grade made a good enough seal to prevent the cracking.