I will take a close look at it later. I have had that type of paint failure (crackling) before on spackled ceilings but not on a flat one. Usualy on flat ceilings, if there is an issue, I will see blistering but I didn't see any hint of that either.

Ok, I took a good close look with a magnifier and I see no evidence of any cracking. It is quite dry now. Its just that the sheen is uneven and shows a lot of roller marks. I understand that this is an issue with newer low voc paints so I guess I am asking what an easier to use alternate paint is.

You bet that paints have changed over the last few years. There really isn't a good ceiling paint available on the market anymore that I can find. I have never liked Muresco though. I used to like Super Spec, but no more. I think the best BM paint for ceilings would be the Aura ceiling paint, though it is a good idea to thin it some because it is very thick stuff. What you describe about the second coat taking more paint is not surprising. A flat paint is not really a good primer for itself and not all flats are the same. Some flats are more porous than others so that when you paint over it, it may soak in more or less. The best way to solve your situation is really to prime the ceiling with a good primer. The good primers will seal the ceiling so that when you paint over it, the paint will not soak into another porous surface as far. This will also give you more open time....the key to having a ceiling come out perfect is to have it so the entire ceiling is wet at the same time and can dry as one. This is the reason we have so many flashing issues with modern day fast drying acrylic paints....by the time you dip your sleeve and return your roller to the ceiling you are painting, the last section you did is already too dry to touch and you get a flash.

Ok, well, I am determined to fix this now.. I'm thinking some 123 Zinzer Primer Sealer.. Some S/W Promar 400 flat paint and maby adding a little conditioner to it. Using an 18" roller. Its a good thing the room is not that big. My next ceiling is freaking huge. At least 600 sq feet and 14' high.

Sounds good. I haven't used Pro Mar 400 for a few years so who knows what state it is in now...at some point in time, it was a good ceiling type paint. The pros who really go for perfect ceilings sometimes even get two guys rolling to really keep that edge wet.

choc-full-o-nuts, please do report back and let us know if the primer solves the problem.

I'm painting over builder's flat and appear to be having similar issues.

I have always hated the way ceiling white "draws" on subsequent coats. Like a sponge. I decided to save myself the anguish, and will always use flat wall paint on ceilings.
Here in WV we are still not in low-VOC-ville as of now. I still can purchase oil paint in gallons, and regular acrylic formulas.
I had an experience with low-VOC floor stain and floor finish last year in VA, which was a FUBAR.
Casey

Will do Safoo. I just finished sanding it. That Valspar paint is seriously tough stuff. Knocking the roller marks off with my palm sander was not so easy. Its only been 2 days and its hard as a rock. The reason for the primer sealer is so that the new paint won't soak into the old paint and drywall and dry too fast.

Ok, well, after 8 coats I am done! Only the last three count though since the disaster was the two primer coats and three coats of Valspar. I sanded it down, put on juicy a coat of 123 with 1/2" purdy white dove. I let it dry for about 28 hours. It had not gotten hard yet but was very dry to the touch. I put about 2 oz of flo and 2 oz of water in it and mixed it up with a drill but there were some lumpy bits in it. I managed to pick most of them off. I think the can was old as it came from the back room of a local niche paint store. It has good leveling properties and I will try it again with a fresher can next time before giving up on it. After it dried, I knocked the lumps down with some 320 paper.

Now, On to the Pro-Mar 400, I cut it in with a brush and rolled with a 9" Purdy Colossus 3/4" Nap 9" all around and then hit it with an 18" Purdy Colossus 3/4" Nap. If you want to try these covers, I would order them on line as the SW store near me charges an arm and leg for them. One other bit of roller info, the 9" and 18" rollers are not exactly the same. The 18" rollers are not as tightly strung. Weird. Also, The Purdy poles are better than the Wooster ones in my opinion. Slightly stiffer and lighter and they thread on better. :-)

That Colossus cover has a bit of a learnng curve but the Pro-Mar 400 is very forgiving relative to the Valspar. I just repeated the same process for the second coat. The ceiling came out very nice except for a few bits from the primer and the Purdy Colossus.

This is one roller cover worth washing, it works better the second time because it doesn't shed. I had washed the rollers out the night before and tacked them off with masking tape but they still shed a bit.

The ProMar 400 paint has that greyish tinge that some folks equate with cheap paint and it certainly doesn't look as lux as the Valspar but it is flatter and smoother and goes well with my 1890's farmhouse theme as it looks very authentic like a calcium wash. The paint is kind of cheap though. It covered well, I didn;t cut it at all and it covered with one coat. I did the second coat to pick up a few missed spots. One of my floodlights exploded and it wasn't as bright as I like.

Just to follow up, I just finished priming the walls with Zinzer 123 Water based primer. I used the purdy wite dove 1/2" Nap on a 9" roller. Going over the previous two coats of Valspar premium primer. There was signifigant sag and it required a fair amount of backrolling to keep the sagging to a minimum. I would use a 3/8" roller in the future. I still like the primer a lot. I boxed two new cans of it through a filter with the leftovers from the ceiling and found a bunch of gunk only in the can I bought from that small local store.

Anyhow, the sags shrink a lot over the first 24 hours. I'm going to leave it for 48 hours before topcoating it.

Thanks everybody.

Well after reading this in 2015 - five years later, I've got the same problem. I purchased BM ceiling paint, which BM told us was supposed to dry to a real flat no-shine finish. We had two professional painters give it two coats and now there are shiny blotches and dull blotches. It did not dry flat over the entire surface. What happened??? There was no primer put on, but the old painted surface was sanded and cleaned before repainting. Any ideas out there?

Me too. I had this problem after using Behr interior ceiling white which is supposed to be flat. After reading that Ben Moore Ceiling paint is probably flatter than others and well rated on-line, I was going to try the 4th coat in that but now I read that Swiftpen had Ben Moore flash on them. I suspect the paints are drying too fast. I'm thinking maybe I could add floetrol or another product that would slow the dry time. My ceiling was smooth/flat and previously white w/ no problems. It was primed, then first coat seemed ok but it needed another. Second coat was when blotches and patches were noticed in a certain light. Third coat did not correct it. Maybe I'll try Ben Moore Ceiling paint 508 for its extra flatness but add some floetrol?

We just did a room with Ben Moore ceiling paint. At first it was very splotchy - shiny in places and flat in others. After a full day of drying it all went flat and looks great. Takes it a while to fully dry. Covered over an old dull dirty lookingyellow really well.

Remember when you paint over a primer, your paint will take longer to dry and so your wet time will be longer and this is what you want. Ideally you want the entire ceiling to be wet at the same time (I realize with good size ceilings you have to move pretty fast). If you apply a second coat, you are now painting over the flat paint that was your first coat and the primer is less of a factor and now your chances at getting flashing and dead spots in the paint film will be greater because the paint is soaking in unevenly. The best way to paint a ceiling is to prime and then do one coat of finish. It's applying that second coat that gives people problems. Also, the nap size matters. Most pros use a 3/4" nap. This is usually too much for a DIY'er to handle without making a mess, but you certainly don't want to use a 3/8". I would use 1/2" nap minimum. Lay that paint on.

What he^ said and try this paint. PPG ceiling paint, gold can, works great

Just like choc full o nuts I to put on coat after coat. First Pittsburg then Valspar color changing after priming with Zinsser Bulls Eye 123. Next was the top of the line Valspar after again priming. What finally worked was Valspar's Signature wall paint base A ultra white 221381. It took about 16 minutes before drying giving me enough time to get the next pass applied while the previous pass was still wet. This was without priming first. it looks nice. Hope this helps