This is usually caused by uneven paint application on broad, flat surfaces, or by over-applying on mouldings or rough-contoured surfaces. Also, failing to join up "wet edges" before they have set can cause excessive film thickness, resulting in sagging and running.
Too much dry rolling (little paiint on the roller), moving it around after the paint is starting to dry. It also depends on what was underneath but from what I see, it's mostly trying to go too far with each roller load.
To fix the peeling area, you can try using a paint scraper to remove any loose paint and sanding the area lightly to create a smooth surface. Then, you can apply a primer/sealer like Zinsser Peel Stop to the area to help the new paint adhere. Follow the manufacturer's instructions for application and drying times.
First you wanna make sure that your roller has as little paint left on it as possible. Then just wrap the sleeve of the roller in aluminum foil and crimp up the sides so that you seal out the air. Now when you get back from lunch, your roller should be ready to paint again.
The old layer did not adhere to the surface. That's usually caused by improper (or no) preparation, such as being applied over a glossy surface without first sanding/etching, or being applied over a paint film that had chalked due to UV exposure.
Different types of paint do not bond well. Applying different paint types together on the same surface can result in paint peeling. Oil-based paints do not adhere to latex-based paints and vice versa. To avoid peeling paint, make sure to always use the same paint type.
Applying the second coat too early will result in lost time, money, and effort. Not only that but it'll also create additional stress that's not necessary. Applying the second coat too early will result in streaks, peeling paint, and uneven color.
Many painters “break in” a roller cover by priming it with water or thinner. In our lab we never prewet a cover before painting. If you choose to, you must spin it out with five or six strong pumps so it is only lightly damp. Then take even more moisture out by blotting the cover with a paper towel.
Don't over-saturate the roller: Avoid overloading the roller with paint, as this can cause it to shed fibers. Use a paint tray to remove any excess paint before applying it to the wall.
Peeling paint must be removed prior to applying a fresh coat of paint to ensure proper adhesion. For Best Results: Refer to the how-to for guidelines on removing peeling paint. Using a scraper or 100-grit sandpaper, remove any loose, cracked, or peeling paint from the damaged area.
Peeling paint is most commonly created when water gets under the paint. Therefore, the most common areas for peeling paint to occur are in the wet areas of a house or building e.g. bathroom, laundry or kitchen. However, there may be other issues with the premises such as excess humidity or a leaky roof.
Moisture. One of the main causes of peeling paint is the presence of moisture or water around the paint. This will usually happen when water gets into the wood behind the paint. This separates it from the wall and seeps through the layer of paint.
Leaks, high humidity or condensation can cause moisture to seep into the wall. When this happens, the bond between the paint and the wall is weakened. The paint eventually loosens and peels off.
Remove all loose and flaking paint with a scraper or wire brush, sand the surface and feather the edges. If the flaking occurs in multiple layers of paint, use of filler may be necessary. Prime bare timber areas before repainting. Use of a premium quality primer and topcoat should prevent a recurrence of the problem.
The first is that the roller was not loaded enough with paint. When this happens, the roller drags across the surface, leaving streaks behind. Another reason for roller marks is when the paint is too thick. In this case, the roller cannot apply the paint evenly to the surface, which results in streaks.
Not Fully Loading the Roller
The roller needs to be fully loaded with paint to the core, otherwise you'll get air bubbles on your wall, resulting in “paint acne.” To avoid this mistake, roll back and forth on the roller tray until all bubbles are gone and the roller feels heavy.
You want to use even, consistent pressure when painting. Remember, pressing too hard will leave behind roller-edge streaks. Not pressing hard enough will lead to inconsistent paint coverage. Practice on a loose piece of drywall to get the feel down before painting your wall.
Recoat Time for Oil-Based Paint
Water-based paints dry considerably faster than oil-based paints because the water evaporates to let the paint dry. Oil-based paints contain no water. Though oil-based paint may feel dry after only a few hours, it's best to wait a full 24 hours or more before applying additional coats.
Storing during a project
Most basic methods include wrapping them in plastic wrap or aluminium foil. If you're waiting overnight or more than 24 hours to get back to painting, you can either place them in an airtight bag, squeezing out all the air, or wrap the roller in a wet towel, then place it in a plastic bag.
Latex paint requires at least four hours before you can add another coat. Wait at least eight to 12 hours before adding another coat of acrylic paint. Oil-based paints require at least 24 hours before you can apply another coat.