No you do not need to remove all old paint, if it will not scrape off or sand off with basic work a good Primer will make a good bond..
Remember you do not need to remove all of the paint, just the damaged and flaking portions of it. Any paint that can just be peeled off needs to be removed as it is not bonded to the underlying layers sufficiently.
Yes, you can paint right over old painted furniture without sanding. You will need something called a DEGLOSSER and you can use this on OLD KITCHEN CABINETS to prep for new paint as well!
Not sanding between coats of paint or varnish can result in a rough or uneven surface texture, visible imperfections like brush marks or drips, and reduced adhesion between layers. Sanding between coats smooths the surface, improves finish adhesion, and enhances the overall quality of the final coat.
It is highly recommended that you scrape off old paint before beginning any project. This will help create a smooth, even surface for your new coat and ensure that the paint adheres to the surface and lasts for years to come.
If the old paint is flaking, bubbling, or peeling off, it might not be a good idea to paint over it directly. This is because the new layer of paint might not adhere properly to the surface, leading to an unattractive and uneven finish. It might also cause the new paint to start peeling prematurely.
A prime may not be necessary if the old paint is in good condition and adequately adhered to the surface. However, if the old paint is peeling, chalking, or flaking, it's best to prime it before applying a new coat. Primer helps create a smooth surface and promotes better adhesion between the old and new paint layers.
The material you're painting will also determine if sanding between coats is necessary. As a general rule, if the surface you just painted doesn't feel or look smooth, sand it!
Requiring no prep work at all, adhesive chalk paint is inherently kind of a miracle if you don't want to sand the surface first—it sticks to so many surfaces. And yes, as a bonus, you can use it as a chalkboard (this actually could be cool on a breakfast table that your kids will be sitting at, just saying).
120-240 Grit
Surprisingly, when you're looking at what grit sandpaper to scuff paint to repaint, this is it. 240-grit sandpaper is one of the most versatile, able to be used to strip paint, shape putty, and blend without noticeable scratches.
As long as the underlying paint is sound, you can paint over it, but to achieve a professional result, you'll need to know the specific factors that will give you a high-quality paint job.
Paint strippers are solvents that soften the old finish for easy removal. They're available as a liquid, gel or paste and are effective at removing paint from wood on large projects, curved shapes and fine details. Using paint stripper on rounded surfaces and tight areas is often easier and more effective than sanding.
Liquid sandpaper is also referred to as deglosser and wet sanding. The advantage of using liquid sandpaper instead of regular sandpaper is that it's easier to apply and safer to use. You just rub liquid sandpaper over the object you wish to paint, wait a set amount of time and wipe off.
Even if you don't have peeling paint, it's always a good idea to scuff up the surface of the old paint with 180-grit sandpaper to provide a good base for the new paint. You don't have to remove all the paint, just focus on the areas where it peels off easily and scuff the other areas where it still adheres.
The good news is that you can paint old furniture, without sanding, and it comes out beautifully. I've painted about 8 or 9 pieces of furniture, and I've gotten better results with each one.
Dimethyl sulfoxide (DMSO) has become more popular since it has a low level of toxicity, making it a safe replacement for methylene chloride and NMP. Opting for a safe active ingredient like DMSO or a manual paint stripping method will be far safer than risking NMP or methylene chloride.
While sanding is not required for every paint project, rough spots on walls, whether they have been previously painted or not, need to be sanded before they are painted to ensure the paint goes on smoothly.
Instead of sanding, use a liquid deglosser to dull the existing finish. This product helps you prepare the surface for new stain or paint without the need to strip or sand.
Many people wonder if they can simply paint over textured walls, and the answer is yes, but it requires a certain process to ensure you get a professional looking paint job. Read on for the step-by-step guide for painting textured walls.
No you do not need to remove all old paint, if it will not scrape off or sand off with basic work a good Primer will make a good bond.. ridges could show .. But it depends on the item. If it is fine furniture, use of paint stripper is not just sand down.
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.
The most effective and long-lasting way to refinish an already-painted item is by stripping it and starting over, rather than layering the new finish on top of the old and getting inconsistent results.
If you've done a good job of scraping away loose chips, most people will not be able to detect the edges of pre-existing paint on the surfaces. Certainly, various wood has unique qualities, but overall, you should not need to sand your exterior prior to painting.
You probably don't need a primer paint if the new coat is the same type as the old paint. For example, both are oil-based. You can just pick the paint color you want and keep going. If the current wall is also smooth and clean, you can head straight for the paint.