How important is it to prime sheetrock before painting? What about if I am painting over existing paint?

If it is possible to skip priming, I would like to. I am in a bit of a rush. But if it is really that important, I will do it.How important is it to prime sheetrock before painting? What about if I am painting over existing paint?
If you are painting over existing paint (depending what it is), you should simply need to rub it down to provide a smooth surface and a key. If you paint new sheetrock, it is absorbent, so needs at least a coat of watered down emulsion before the finish coat or it will be patchy. It isn't really necessary to use special primer, though it does give a better finish.How important is it to prime sheetrock before painting? What about if I am painting over existing paint?
You should definately prime first. The paper on the sheetrock will absorb a lot of paint meaning at least 2 coats to get good coverage. More for certain colors like reds. With a good primer you'll get a more even color and may just need one coat of paint after saving time and some cash
With all due respect; I've applied multiple thousands of gallons of paint in my time; still work at it; and rarely do I prime even RAW. I do most usually apply two coats of whatever color however. I don't consider it cheating at all, and certainly raw drywall will absorb any agent without a lot of pigment or polymers in it. I like to think of it this way.





';I'm probably going to paint two coats anyway; of a quality substance; so why not apply the first coat in the color already chosen.'; If the paint you use is any good; by the second coat there should be few issues. That said... MUD will appear differently through any first coat, than the raw drywall does; so you may just prime the patch and sand areas. For me it's steps taken not strictly neccesary.





Then there are issues in painting over painted surfaces.





Anything applied over a Gloss/Semi gloss/Latex over Oil, or reverse, should be primed first.





In the end just purchase a decent product; Spend a couple extra dollars per gallon; and in the majority of cases I use ';Satin'; it's less porous than FLAT and allows a better ';cleanability'; after the fact.





Steven Wolf
You don't need to prime over existing paint unless the old paint is dark in color and you want to repaint with a lighter color. Painting over dark paint without a primer will cause the darker paint to bleed through the color of the new lighter paint. It is also very important to paint over existing paint with the right base. First thing you need to do if determine the base of the extisting paint. To do this, use nail polish remover or gas line antifreeze (metholhydrate) and rub on the wall with a rag or paper towel. If the paint comes off you have a latex (acrylic) base, if it stays on you have an oil (alkyd) base. You can use latex over latex, oil over latex, but you can't use latex over oil. Using latex over oil will create a severe bonding issue with the new paint. New sheetrock needs to be primed before painting to create a bond and to eliminate streaking of paint, coverage will be poor without a primer and not using primer will cause the drywall compounds to bleed through the paint. You can purchase a primer that is strictly used for new sheetrock and is less expensive than a primer sealer. Use a primer sealer when repainting a light color over a dark one to eliminate a bleed through of color.
its important to prime on brand new rock to seal the surface from drinking your paint. also, if you already have a strong color because the primer prepares the surface for the next color.
i prime all surfaces before painting myself.watch what type of paint you are painting over you do not want to paint latex over oil paint with out the proper prep work..not once did i see someone paint on drywall without priming.
nobody is in that big of a hurry. Dont skip the primer. Havent you ever heard to always do a good job? If the quality isnt there, then whats the purpose?
Any answer that says ';don't worry about priming'; is a stupid answer. There is a right and wrong way to do any deed in life and not priming bare sheetrock is one of them, gotta laugh because on most of these answers they say to prime over glossy finish or prime a dark color, you need no primer for this deed, gloss finish either lightly sand or wipe down with a liquid deglosser, these are woodwork areas and not whole walls and when it comes to changing an existing color you'll 9 out of 10 ten times use 2 coats of finish, do yourself a favor and do the ';MOST IMPORTANT'; step in painting and use a primer on first coat on any ';NEW'; surface!!! Good luck Les the painter
It's up to you, but I've found that if you are using a color darker than the color of sand, you'll be happier if you did.





Try this:





Take two parts of the same wall receiving the same light. They don't have to be much larger than a 2x2 foot section for each. Prime one part followed by two coats of your final color. On the other section, just apply two coats.





Do they look any different?
I recently had new drywall installed in my home (6 rooms). My drywall finisher (30+ years exper) felt that it was so important to prime the new drywall, he provided 10 gallons of Sherman Williams primer-with the advice to ';BE SURE TO USE PRIMER .';


I understand being in a bit of a hurry, I was too, but you can have your primer tinted to help you along, at no additional charge. The whole process is not inexpensive, don't skip the important stuff now.


AJMiller Drywall, New Philadelphia Ohio-in case you are interested.