How should I paint my new drywall??
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How should I paint my new drywall??
We are finishing the room above the garage and will soon have all the taping an mudding done. I'm trying to figure out the best way to paint all of the area.
There are several rooms... Bedroom with closet and behind the kneelwall "play area", bathroom with a knee wall storage, a storage room, hallway, and rec room.
There are no floors or trim to deal with so I thought that spraying might be the best way to go. I bought a HVLP gun (Tool Force A-C1 50 PSI 2-in-1 HVLP Spray Gun) and some folks have used it successfully after thinning. But I've also read that it would take me forever! So I'm inclined to rent an airless.
Am I right in not wanting to try the HVLP gun with this? I'm guessing about 1500sqft of area (maybe more).
I assume I can use the HVLP to paint the trim when it comes time..
Also.. I assume that a bunch of the "no primer necessary" paint don't apply to fresh drywall, right?
Thanks!
Jim
There are several rooms... Bedroom with closet and behind the kneelwall "play area", bathroom with a knee wall storage, a storage room, hallway, and rec room.
There are no floors or trim to deal with so I thought that spraying might be the best way to go. I bought a HVLP gun (Tool Force A-C1 50 PSI 2-in-1 HVLP Spray Gun) and some folks have used it successfully after thinning. But I've also read that it would take me forever! So I'm inclined to rent an airless.
Am I right in not wanting to try the HVLP gun with this? I'm guessing about 1500sqft of area (maybe more).
I assume I can use the HVLP to paint the trim when it comes time..
Also.. I assume that a bunch of the "no primer necessary" paint don't apply to fresh drywall, right?
Thanks!
Jim
#2
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I would stick to brushes and rollers, I'm not a fan of spraying paint indoors - the paint being airborne means a lot more work goes into containing the mess and, IMO, the benefit is not worth the extra effort
I would buy quality paints and primers from a paint store, not a paint department in a big store
I would buy quality paints and primers from a paint store, not a paint department in a big store
#4
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You have enough compressor to run the gun? If so, I guess that's a viable option
BM's good paint, it's what I use (just don't use the bottom of the line stuff - in any brand), I put Zinsser primers underneath - 123 is a good choice for new drywall
BM's good paint, it's what I use (just don't use the bottom of the line stuff - in any brand), I put Zinsser primers underneath - 123 is a good choice for new drywall
#5
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An HVLP won't spray latex paint/primer unless it's drastically thinned. You need an airless to spray latex coatings. You'll be better off with a good roller and brush. Separate primer and paint is almost always best.
#7
No, even if a professional quality airless paint sprayer fell out of the clear blue sky and landed gently in your back yard, it still would't be worth your time to use it. And, here's why:
More and more painting contracts where the presumed method of application will be spraying are calling for "back rolling". What they've recently discovered is that even though spray painting can put the paint on real fast, it doesn't force the liquid paint or primer into a porous surface the way a brush or roller does. The result is a primer or paint film that looks fine, but simply doesn't adhere to the porous surface as well as primer or paint applied with a brush or roller does.
To address this problem, painting contracts are now requiring primer sprayed onto porous surface (wood, drywall, cement board, etc.) and paint applied to the primer to be "back rolled". What that means is that the senior painter sprays the primer or paint on, and the junior guy follows immediately behind him, rolling the still wet primer or paint with a paint roller to force it into the porous surface. If you go down to the places where the painting contractors in your area buy their supplies, you'll see special roller frames made so that you can slide a 10 inch wide roller sleeve onto both sides of a special roller frame for an effective width of a little over 20 inches. It's these kinds of double roller frames that are commonly used for back rolling.
A second reason to back roll is that, contrary to popular belief, it actually takes years of experience to apply spray paint uniformly. Most people compensate for that by applying multiple thin coats of paint until the entire surface is covered, but spraying your drywall multiple times is probably not what you were anticipating. If you don't have that skill or experience, you're likely to end up with a blotchly looking primer and then a blotchy looking top coat because of the unavoidable variation in the amount of primer and paint that was sprayed on to each square inch. Back rolling ensures that the primer and paint coats are spread uniformly over the surface regardless of how non-uniformly they were sprayed on, and the result is that both the primer coat and top coat "look better". Just buy yourself a can of spray paint and try spray painting a cardboard box and see how well you do. If you get a blotchy box, you can pretty much expect a blotchy wall.
A third reason to back roll is that paint applied with a roller has a "nubbly" texture to it. Should you ever need to repair your drywall (because someone slapshotted a hockey puck through it, or whatever), then you won't be able to repair that damage properly unless the texture of the paint you apply matches that of the surrounding wall. And, that's the problem. You simply won't get the same texture using a roller or brush as the smooth surface you get with spraying alone. When a ceiling light or light from a window reflects off that repair, any change in the texture of the painted surface will stand out as plainly as if the paint were a different colour. By back rolling, you establish that nubbly texture on the wall, thereby making it possible to only paint over your repairs with a roller and match the nubbly texture of the wall.
But, don't just take my word for it...
Back Rolling a Spray Job | Breaktime
Back Rolling a Spray Job - Painting & Finish Work - Contractor Talk
Use back rolling or back brushing to increase the paints adhesion.
So, do the math. If you're wanting to do the best job you can, then you're gonna be back rolling anyway. And then the question becomes, if I'm gonna back roll, then why don't I just roll in the first place? So, now what are you gonna do I do with the airless paint sprayer in the back yard?
Spraying and back rolling goes faster than rolling alone if there are two people working and the smaller, younger one is using a 20 inch wide roller. But when there's only one guy working, then it'll both take longer and be more work to spray and back roll rather than to just roll in the first place.
Last edited by Nestor; 05-25-11 at 10:13 PM.
#8
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"What they've recently discovered is that even though spray painting can put the paint on real fast, it doesn't force the liquid paint or primer into a porous surface the way a brush or roller does"
That's been a well know fact for decades.... at least by the painting trade
I almost always spray interior walls/ceilings on new construction but I seldom spray remodels or small additions. There is a lot of prep involved and unless you are applying multiple 5 gallon buckets of paint - there isn't any time savings. I never spray inside of an occupied dwelling.
Once you made sure all the drywall dust has been removed, apply your primer 1st with a roller, then go back and cut in what the roller didn't get. Before applying the finish paint, sand lightly [a pole sander works best] then cut in and then roll a section/wall at a time.
That's been a well know fact for decades.... at least by the painting trade
I almost always spray interior walls/ceilings on new construction but I seldom spray remodels or small additions. There is a lot of prep involved and unless you are applying multiple 5 gallon buckets of paint - there isn't any time savings. I never spray inside of an occupied dwelling.
Once you made sure all the drywall dust has been removed, apply your primer 1st with a roller, then go back and cut in what the roller didn't get. Before applying the finish paint, sand lightly [a pole sander works best] then cut in and then roll a section/wall at a time.
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Once you made sure all the drywall dust has been removed, apply your primer 1st with a roller, then go back and cut in what the roller didn't get. Before applying the finish paint, sand lightly [a pole sander works best] then cut in and then roll a section/wall at a time.
I think I've been talked out of spraying. The wife, being near full term, will probably not want to be back rolling for me!
#10
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You can spray and backroll by yourself but you really have to know how to work
I know there are some diyers that are fanatical about removing the dust but as long as the majority is gone - it should be fine. I like to use my push broom minus the handle to sweep off the drywall dust. Be sure to check the ceiling too - I don't know why drywall dust will hang on upside down but it does.
I know there are some diyers that are fanatical about removing the dust but as long as the majority is gone - it should be fine. I like to use my push broom minus the handle to sweep off the drywall dust. Be sure to check the ceiling too - I don't know why drywall dust will hang on upside down but it does.
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I know there are some diyers that are fanatical about removing the dust but as long as the majority is gone
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I don't think I'm going to rent the airless. HD wants $86/day!
I think I'll take the extra time and just "roll with it"
My neighbor, who is a contractor, suggested I prime with ceiling paint. this way I don't have to worry about cutting in when I prime the walls? What do you think? It that done? It might cost me a couple bucks more.. but if I don't have to cut the ceiling....
Jim
I think I'll take the extra time and just "roll with it"
My neighbor, who is a contractor, suggested I prime with ceiling paint. this way I don't have to worry about cutting in when I prime the walls? What do you think? It that done? It might cost me a couple bucks more.. but if I don't have to cut the ceiling....
Jim
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I'm at a total loss on this last post - ceiling paint as primer? I can't see how that would make any difference plus paint and primer have different jobs, I would personally not use paint as primer.
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That's why I asked... It seemed strange to me... but you never know.. Maybe he has some special paint in mind. I've hear people using primer as a final coat on ceilings..
I think I'll stick with 1 coat of primer (everywhere) and 1 coat of ceiling paint on the ceiling and 2 coats on the walls...
I think I'll stick with 1 coat of primer (everywhere) and 1 coat of ceiling paint on the ceiling and 2 coats on the walls...
#17
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It's ok to get the ceiling paint on the wall [after priming everything first] Generally trying to cut the ceiling paint cleanly next to the wall is a wasted effort. On new construction I rarely cut in the primer, for the most part I can get close enough with either a roller or using a spray shield.
Some contractors will skip the primer over textured ceilings [and sometimes walls] but that isn't the correct way to do the job and a job done right always looks better in the end, should also wear better.
I haven't rented an airless in a long time but I always rented them from a tool rental place - there prices may or may not be cheaper...... but as stated before, your job really isn't a good candidate for spray.
Some contractors will skip the primer over textured ceilings [and sometimes walls] but that isn't the correct way to do the job and a job done right always looks better in the end, should also wear better.
I haven't rented an airless in a long time but I always rented them from a tool rental place - there prices may or may not be cheaper...... but as stated before, your job really isn't a good candidate for spray.
#18
Jim:
Paint companies try to tailor their paints to best suit their intended purpose. Ceilings don't need to be cleaned often because they rarely get any marks or dirt on them, so ceiling paints will use a lesser grade of binder and softer extender pigments that simply won't stand up to scrubbing well.
Also, flat paints are cheaper than gloss paints because extender pigments are cheaper than binder resins. To make a glossier paint, your ratio of expensive acrylic binder resin to cheap extender pigment has to go up, and that's what makes gloss paints more expensive than flat paints (everything else being equal). Since flat paints scatter light and hide defects in drywall and plaster better than gloss paints, ceiling paints will typically be flat (and therefore less expensive).
In a nutshell, ceiling paints are simply wall paints made to a lower level of quality.
When a paint company is making a primer, the top priority will be that the primer use a binder resin that has excellent adhesion. After all, that's what a primer is meant to do; stick well to the substrate and make it easy for the top coat to stick well to it. But, when a paint company is making a ceiling paint, they're thinking that the paint they're making doesn't have to stand up to much, and so they really don't need as high adhesion as you need in a primer or as hard a plastic film as you need in a wall paint, and so cost becomes a relatively more important consideration and they end up making a low quality wall paint to be used on ceilings.
I'd use a primer to prime, and a top quality wall paint on your ceilings.
As to cutting in, you should be aware that most people have trouble cutting in because they're not using their brush properly.
Most people see a sash brush...
and conclude it's made that way because it's meant to be used like this:
and they're wrong. The bristles on a sash brush are cut at an angle so that the brush can be used like this:
If you have sufficient hand-eye co-ordination to follow a straight line with your brush, and sufficient intellectual capacity to remember this post, you won't have any trouble cutting it with a sash brush. If you hold the sash brush wrong, you're going to have no end of trouble cutting in.
Paint companies try to tailor their paints to best suit their intended purpose. Ceilings don't need to be cleaned often because they rarely get any marks or dirt on them, so ceiling paints will use a lesser grade of binder and softer extender pigments that simply won't stand up to scrubbing well.
Also, flat paints are cheaper than gloss paints because extender pigments are cheaper than binder resins. To make a glossier paint, your ratio of expensive acrylic binder resin to cheap extender pigment has to go up, and that's what makes gloss paints more expensive than flat paints (everything else being equal). Since flat paints scatter light and hide defects in drywall and plaster better than gloss paints, ceiling paints will typically be flat (and therefore less expensive).
In a nutshell, ceiling paints are simply wall paints made to a lower level of quality.
When a paint company is making a primer, the top priority will be that the primer use a binder resin that has excellent adhesion. After all, that's what a primer is meant to do; stick well to the substrate and make it easy for the top coat to stick well to it. But, when a paint company is making a ceiling paint, they're thinking that the paint they're making doesn't have to stand up to much, and so they really don't need as high adhesion as you need in a primer or as hard a plastic film as you need in a wall paint, and so cost becomes a relatively more important consideration and they end up making a low quality wall paint to be used on ceilings.
I'd use a primer to prime, and a top quality wall paint on your ceilings.
As to cutting in, you should be aware that most people have trouble cutting in because they're not using their brush properly.
Most people see a sash brush...
and conclude it's made that way because it's meant to be used like this:
and they're wrong. The bristles on a sash brush are cut at an angle so that the brush can be used like this:
If you have sufficient hand-eye co-ordination to follow a straight line with your brush, and sufficient intellectual capacity to remember this post, you won't have any trouble cutting it with a sash brush. If you hold the sash brush wrong, you're going to have no end of trouble cutting in.
Last edited by Nestor; 06-01-11 at 01:59 AM.
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Jim:
The bristles on a sash brush are cut at an angle so that the brush can be used like this:
If you have sufficient hand-eye co-ordination to follow a straight line with your brush, and sufficient intellectual capacity to remember this post, you won't have any trouble cutting it with a sash brush. If you hold the sash brush wrong, you're going to have no end of trouble cutting in.
The bristles on a sash brush are cut at an angle so that the brush can be used like this:
If you have sufficient hand-eye co-ordination to follow a straight line with your brush, and sufficient intellectual capacity to remember this post, you won't have any trouble cutting it with a sash brush. If you hold the sash brush wrong, you're going to have no end of trouble cutting in.
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But I don't want to be proficient at it! I hate painting!
but this project is so big that I may actually be faster at it by the time it's all done!
What do you guys think about this guy. He seems to be saying that primer isn't so good for bare drywall and if you anything use a sealer??
Jim
but this project is so big that I may actually be faster at it by the time it's all done!
What do you guys think about this guy. He seems to be saying that primer isn't so good for bare drywall and if you anything use a sealer??
Jim
#22
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I didn't take the time to read all his info but I'm not sure I agree with everything I read. There are many different primers, quality aside, that preform different tasks. Sealers seal the wall, a primer sealer seals but also adds some color to the wall making the next coat cover better. Some primers are better as an undercoater for latex enamels. HiBuild primers are used to help fix minor defects in the drywall finish.... the list goes on.
Generally if a primer fails it is because either the wrong primer was used or the substrate was improperly prepared.
As an employee, I painted a lot of new construction where we didn't use a primer The same top coat used over the right primer will be a LOT more washable. As a contractor, most of the new homes I painted were primed with SWP's preprite wall primer [used a hibuild primer on the ceilings] a latex undercoater was often used on the walls that were to be painted with latex enamel. SWP's promar 200 was the finish paint most often used on the walls. Some customers would request [and pay for] a higher grade of paint. I never got any complaints about the quality of my paint jobs and my painted walls consistently looked better than the competitions.
Generally if a primer fails it is because either the wrong primer was used or the substrate was improperly prepared.
As an employee, I painted a lot of new construction where we didn't use a primer The same top coat used over the right primer will be a LOT more washable. As a contractor, most of the new homes I painted were primed with SWP's preprite wall primer [used a hibuild primer on the ceilings] a latex undercoater was often used on the walls that were to be painted with latex enamel. SWP's promar 200 was the finish paint most often used on the walls. Some customers would request [and pay for] a higher grade of paint. I never got any complaints about the quality of my paint jobs and my painted walls consistently looked better than the competitions.
#23
Jim: Lemme read that web page, and I'll post a comment later.
In house painting, every general purpose Primer also acts as Sealer when used over drywall or joint compound. That's why most general purpose primers advertise themselves as being a "Primer/Sealer". And, in the case of latex primers, they most often call themselves an "Indoor/Outdoor Primer/Sealer".
That's because both latex and oil based primers contain huge rocks that are almost large enough to see with the naked eye called "extender pigments". It's these extender pigments that make primers dry to a flat gloss so that the top coat of paint sticks well to the primer. But, it's also these extender pigments that plug up the surface porosity of drywall and joint compound, thereby limiting the amount of primer/sealer that gets absorbed into these substrates. So, the same rocks that make the primer dry to a flat gloss also cause it to work as a sealer on drywall and joint compound.
A flat ceiling paint would probably work similar to a primer because ceiling paints are normally flat, and therefore have fairly large extender pigments in them. However, any paint company making a PRIMER is going to choose a resin that excellent adhesion to BARE substrates, like bare drywall, bare joint compound, bare wood, etc. The same can't be said about a ceiling paint which would typically be appied over primer or another paint. Ditto for the extender pigments that are used. In a primer, they'll be the right size to seal up drywall paper and joint compound. In a ceiling paint, they only have to be big enough to make the paint dry to a flat gloss. So, using ceiling paint as a drywall primer would work better than using a high gloss paint as a drywall primer, but not as well as using a drywall primer.
PS:
A "primer" is something that sticks well to the substrate and enhances the adhesion of the top coat to it. Rustoleum makes oil based primers for metal that have no sealing function whatsoever.
A "sealer" is something that prevents fluid migration into or out of the substrate. You can buy masonary and grout sealers which have no priming function whatsoever.
The extender pigments in latex and oil based general purpose primers perform BOTH jobs by causing the primer to dry to a flat gloss and by plugging up the surface porosity of drywall and joint compound.
Note that using a primer on bare wood has no "sealing" function, except where you're using an oil based primer to prevent tannin staining that would otherwise occur if you were to use a latex primer. Latex binder resins are far too large to penetrate into wood, and so latex primers aren't absorbed into wood like they are into drywall paper and joint compound. That's why they'll often call a primer that's intended to be used over wood or metal a "primer/undercoat" instead of a primer/sealer.
In house painting, every general purpose Primer also acts as Sealer when used over drywall or joint compound. That's why most general purpose primers advertise themselves as being a "Primer/Sealer". And, in the case of latex primers, they most often call themselves an "Indoor/Outdoor Primer/Sealer".
That's because both latex and oil based primers contain huge rocks that are almost large enough to see with the naked eye called "extender pigments". It's these extender pigments that make primers dry to a flat gloss so that the top coat of paint sticks well to the primer. But, it's also these extender pigments that plug up the surface porosity of drywall and joint compound, thereby limiting the amount of primer/sealer that gets absorbed into these substrates. So, the same rocks that make the primer dry to a flat gloss also cause it to work as a sealer on drywall and joint compound.
A flat ceiling paint would probably work similar to a primer because ceiling paints are normally flat, and therefore have fairly large extender pigments in them. However, any paint company making a PRIMER is going to choose a resin that excellent adhesion to BARE substrates, like bare drywall, bare joint compound, bare wood, etc. The same can't be said about a ceiling paint which would typically be appied over primer or another paint. Ditto for the extender pigments that are used. In a primer, they'll be the right size to seal up drywall paper and joint compound. In a ceiling paint, they only have to be big enough to make the paint dry to a flat gloss. So, using ceiling paint as a drywall primer would work better than using a high gloss paint as a drywall primer, but not as well as using a drywall primer.
PS:
A "primer" is something that sticks well to the substrate and enhances the adhesion of the top coat to it. Rustoleum makes oil based primers for metal that have no sealing function whatsoever.
A "sealer" is something that prevents fluid migration into or out of the substrate. You can buy masonary and grout sealers which have no priming function whatsoever.
The extender pigments in latex and oil based general purpose primers perform BOTH jobs by causing the primer to dry to a flat gloss and by plugging up the surface porosity of drywall and joint compound.
Note that using a primer on bare wood has no "sealing" function, except where you're using an oil based primer to prevent tannin staining that would otherwise occur if you were to use a latex primer. Latex binder resins are far too large to penetrate into wood, and so latex primers aren't absorbed into wood like they are into drywall paper and joint compound. That's why they'll often call a primer that's intended to be used over wood or metal a "primer/undercoat" instead of a primer/sealer.
Last edited by Nestor; 06-01-11 at 06:54 PM.
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I wasn't referring to my neighbor.. I was referring to the link that "this" pointed to.. its a link to some guy called Jack Pauhl. It provides some decent examples of how primer was actually made things worse. He has some imperial data.. I was looking to see what some of you guys think. Is he nuts? Is there merit in what he says?
#25
I think the problem is that he's extrapolating too much.
From what I can see, the guy is saying two things:
1. Painting two coats of eggshell paint on bare drywall yields better adhesion of the paint to the drywall than one coat of paint and one of primer.
2. Priming creates problems (which he calls "gloss degradation").
If you read my previous post that explained the roll of extender pigments in primers, then it does make sense that the eggshell paint (which allowed more paint penetration in to the drywall paper) would result in better adhesion. More paint has penetrated into more paper, and so the first coat is holding on better than a primer coat would where less binder penetrates into the paper.
But, I remember trying to use paint as a primer on bare joint compound, and I still remember that it took me FIVE (count 'em, FIVE) coats of satin paint to get the same gloss level in the paint over the joint compound as on the surrounding painted wall. No one is gonna want to start putting 5 coats of paint over anything under any circumstances.
And, I can understand his point that painting an eggshell paint over an eggshell paint results in a smoother and more attractive surface than painting that eggshell paint over primer. That's simply because the paint film thickness decreases as the paint dries. If the substrate (in this case, the primer) is rough, then you can expect that some of that roughness is going to telegraph through onto the new paint and result in it being rougher than it would otherwise be.
However, anyone who's ever painted knows that there's no agreement amongst paint companies as to how glossy eggshell, velvet, satin or even semi-gloss is. Behr eggshell paint, from what I've seen, is flatter than other companies "flat" paints.
So, while this Jack Pauhl may have gotten better results using an eggshell paint as his primer, it's foolish for him to extrapolate that result and say "Don't use a primer." or "Use two coats of paint instead."
That's because had he used a different drywall joint compound (that had more glue in it, or less), or had he used a different paint gloss (like satin instead of eggshell), then his results would have been different.
Also, I'm not sold on this "gloss degradation" thing. When people choose a gloss level, they just know if they want the paint glossy or flat or something in between. Most people spend much more time on deciding the colour than the gloss level. The fact that a paint is going to be a little flatter if painted over a primer than if painted over glass is something that most people wouldn't be concerned about. It seems to me that Jack Pauhl is looking for a reason to tell people not to use a primer, and the only argument he can find is that the gloss level will be a little off. Truth be known, no one really cares if the gloss level is a little off, provided it's not completely different than the customer was wanting.
Mr. Pauhl is correct that paint adhesion is tested with masking tape. However, the way he did his test isn't the way it's done by paint companies. Paint companies have a tool that has either 6 or 11 razor blades mounted in it. That tool is used to cut the paint horizontally, and then vertically, making a "checkerboard" with 25 or 100 squares. Masking tape is then stuck to the paint over that checkerboard, and the paint quickly pulled off. The number of squares of paint that remained sticking to the substrate is then counted, and the result is a "percent adhesion" (or multiplied by 4 to get a percent adhesion). Good adhesion is generally considered to be over 80 percent.
I also agree with Mr. Pauhl's self admission that testing the adhesion of the paint after only 24 hours drying time is premature. What he should have done is waited for that "freshly painted smell" to have come and gone. That smell is the coalescing solvents in the paint evaporating, which is the last thing to happen in a regular latex paint as it forms a film. So, after the coalescign solvents evaporate, then there's no further changes in the paint. (Higher quality paints use cross-linking acrylic resins which form films just like a regular latex paint, but then over the next 30 days or so, crosslinks develop within and between resins to cause a hardening of the latex paint film. Latex Porch and Floor paints and top quality interior latex paints will typically use cross linking acrylic resins. It would have been more correct to test the paint's adhesion after 3 or 4 days, or after 30 days.
I've never used Zinsser's Gardz primer, but my understanding is that it's intended to be used over damaged drywall paper, not as a general purpose primer. I really don't know what Gardz is or how it works, so I can't comment on Mr. Pauhl's assertion that it's a drywall "sealer" without also being a drywall primer. I do know that Gardz is a relatively unique product, and that the vast majority of drywall primers are also drywall sealers for the reasons explained in my previous post.
If I were you, I would try using two coats of paint and try using one coat of primer and one coat of paint and see which one looks better to you, and which one stays on better using Mr. Pauhl's adhesion test, and decide for yourself. There's nothing wrong with using a paint as it's own primer, it's just that you're going to get different results depending on the gloss level of your paint, the porosity of the drywall paper and joint compound, and other factors. What really matters is:
1. How well is the paint holding on?
2. Does the paint stand up well to scrubbing, moisture/humidity, and am I happy with it's performance? Is it easy to keep clean?
3. How good does the paint job look? (You want to see a UNIFORM gloss level everywhere.)
I'd also do your testing on an area of wall or ceiling where you can see the reflection of light from a window. In my case, I rarely prime or paint over drywall. Most of the painting I do is over joint compound (as in repairing nail holes) or over paint. I think you'll find that the gloss level of a primer won't vary from drywall paper to joint compound, but the gloss level of paint will vary considerably depending mostly on it's gloss level. I expect joint compound will absorb a lot more paint than paper, and I expect you'll find that's especially true as you go to using higher gloss paints as your primer.
In a nutshell, it's not uncommon for people to use a paint as it's own primer. However, if that gave consistantly better results than using a primer, Mr. Pauhl wouldn't be the lone wolf calling in the wilderness. It would be widely known, and everyone would be doing it. Mr. Pauhl's results just aren't typical of most people's experience, and I expect he'd get different results too if he used different paints as primers.
From what I can see, the guy is saying two things:
1. Painting two coats of eggshell paint on bare drywall yields better adhesion of the paint to the drywall than one coat of paint and one of primer.
2. Priming creates problems (which he calls "gloss degradation").
If you read my previous post that explained the roll of extender pigments in primers, then it does make sense that the eggshell paint (which allowed more paint penetration in to the drywall paper) would result in better adhesion. More paint has penetrated into more paper, and so the first coat is holding on better than a primer coat would where less binder penetrates into the paper.
But, I remember trying to use paint as a primer on bare joint compound, and I still remember that it took me FIVE (count 'em, FIVE) coats of satin paint to get the same gloss level in the paint over the joint compound as on the surrounding painted wall. No one is gonna want to start putting 5 coats of paint over anything under any circumstances.
And, I can understand his point that painting an eggshell paint over an eggshell paint results in a smoother and more attractive surface than painting that eggshell paint over primer. That's simply because the paint film thickness decreases as the paint dries. If the substrate (in this case, the primer) is rough, then you can expect that some of that roughness is going to telegraph through onto the new paint and result in it being rougher than it would otherwise be.
However, anyone who's ever painted knows that there's no agreement amongst paint companies as to how glossy eggshell, velvet, satin or even semi-gloss is. Behr eggshell paint, from what I've seen, is flatter than other companies "flat" paints.
So, while this Jack Pauhl may have gotten better results using an eggshell paint as his primer, it's foolish for him to extrapolate that result and say "Don't use a primer." or "Use two coats of paint instead."
That's because had he used a different drywall joint compound (that had more glue in it, or less), or had he used a different paint gloss (like satin instead of eggshell), then his results would have been different.
Also, I'm not sold on this "gloss degradation" thing. When people choose a gloss level, they just know if they want the paint glossy or flat or something in between. Most people spend much more time on deciding the colour than the gloss level. The fact that a paint is going to be a little flatter if painted over a primer than if painted over glass is something that most people wouldn't be concerned about. It seems to me that Jack Pauhl is looking for a reason to tell people not to use a primer, and the only argument he can find is that the gloss level will be a little off. Truth be known, no one really cares if the gloss level is a little off, provided it's not completely different than the customer was wanting.
Mr. Pauhl is correct that paint adhesion is tested with masking tape. However, the way he did his test isn't the way it's done by paint companies. Paint companies have a tool that has either 6 or 11 razor blades mounted in it. That tool is used to cut the paint horizontally, and then vertically, making a "checkerboard" with 25 or 100 squares. Masking tape is then stuck to the paint over that checkerboard, and the paint quickly pulled off. The number of squares of paint that remained sticking to the substrate is then counted, and the result is a "percent adhesion" (or multiplied by 4 to get a percent adhesion). Good adhesion is generally considered to be over 80 percent.
I also agree with Mr. Pauhl's self admission that testing the adhesion of the paint after only 24 hours drying time is premature. What he should have done is waited for that "freshly painted smell" to have come and gone. That smell is the coalescing solvents in the paint evaporating, which is the last thing to happen in a regular latex paint as it forms a film. So, after the coalescign solvents evaporate, then there's no further changes in the paint. (Higher quality paints use cross-linking acrylic resins which form films just like a regular latex paint, but then over the next 30 days or so, crosslinks develop within and between resins to cause a hardening of the latex paint film. Latex Porch and Floor paints and top quality interior latex paints will typically use cross linking acrylic resins. It would have been more correct to test the paint's adhesion after 3 or 4 days, or after 30 days.
I've never used Zinsser's Gardz primer, but my understanding is that it's intended to be used over damaged drywall paper, not as a general purpose primer. I really don't know what Gardz is or how it works, so I can't comment on Mr. Pauhl's assertion that it's a drywall "sealer" without also being a drywall primer. I do know that Gardz is a relatively unique product, and that the vast majority of drywall primers are also drywall sealers for the reasons explained in my previous post.
If I were you, I would try using two coats of paint and try using one coat of primer and one coat of paint and see which one looks better to you, and which one stays on better using Mr. Pauhl's adhesion test, and decide for yourself. There's nothing wrong with using a paint as it's own primer, it's just that you're going to get different results depending on the gloss level of your paint, the porosity of the drywall paper and joint compound, and other factors. What really matters is:
1. How well is the paint holding on?
2. Does the paint stand up well to scrubbing, moisture/humidity, and am I happy with it's performance? Is it easy to keep clean?
3. How good does the paint job look? (You want to see a UNIFORM gloss level everywhere.)
I'd also do your testing on an area of wall or ceiling where you can see the reflection of light from a window. In my case, I rarely prime or paint over drywall. Most of the painting I do is over joint compound (as in repairing nail holes) or over paint. I think you'll find that the gloss level of a primer won't vary from drywall paper to joint compound, but the gloss level of paint will vary considerably depending mostly on it's gloss level. I expect joint compound will absorb a lot more paint than paper, and I expect you'll find that's especially true as you go to using higher gloss paints as your primer.
In a nutshell, it's not uncommon for people to use a paint as it's own primer. However, if that gave consistantly better results than using a primer, Mr. Pauhl wouldn't be the lone wolf calling in the wilderness. It would be widely known, and everyone would be doing it. Mr. Pauhl's results just aren't typical of most people's experience, and I expect he'd get different results too if he used different paints as primers.
Last edited by Nestor; 06-01-11 at 10:02 PM.
#26
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Zinnser's Gardz is primarily used to seal drywall after wallpaper removal. It will do a decent job of sealing most any drywall [not stains] but it really doesn't have any hiding properties so painting over it would be harder to get coverage than painting over most any other primer.
Most any paint with a sheen can have gloss retention problems especially when you need to touch it up. Using the right primer [latex enamel undercoater] will go a long way towards helping the enamel to have a consistent sheen. It also helps to know where you can touch up and where the touch up well show no matter what. Any paint with a sheen that can be seen at a long angle is apt to have the touch up show. The same is true of flat paint but to a lesser extent.
Most any paint with a sheen can have gloss retention problems especially when you need to touch it up. Using the right primer [latex enamel undercoater] will go a long way towards helping the enamel to have a consistent sheen. It also helps to know where you can touch up and where the touch up well show no matter what. Any paint with a sheen that can be seen at a long angle is apt to have the touch up show. The same is true of flat paint but to a lesser extent.
#27
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It's going to take a lot more than one person decrying primer to get me to change my process - marksr knows more about painting than anyone else I've ever encountered and he uses primer, that alone would be enough for me
#28
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should I buy the wide roller???
The Tape/Mud guy is done. Time to prime and paint (which I'm not looking forward to! )
Would it be in my best interests to get the big (18" wide) rollers? I have probably close to 2000 sqft of walls and ceilings to paint! I must have 4 or 5 9" roller cages..
But I'm not against buying another one (18") to speed things up. But I'll have to get the roller tray as well! (well.. and the roller covers too)
Would it be in my best interests to get the big (18" wide) rollers? I have probably close to 2000 sqft of walls and ceilings to paint! I must have 4 or 5 9" roller cages..
But I'm not against buying another one (18") to speed things up. But I'll have to get the roller tray as well! (well.. and the roller covers too)
#29
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I wouldn't bother, an 18" roller is geared more for commercial work. The few times that I've used one we used a wheel barrow to hold the paint. Also you can roll as close to the corners with an 18" roller like you can with the standard 9" Using a tray will slow you down, instead pour your paint into a 5 gallon bucket and use a roller screen/grid. I'm sure you know to use a roller pole
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Well I do have several 5 gal containers left over from the mud guy. Something tells me if I try the roller screen I'll never go back to the tray!
I do have several poles.. I just have to try and remember where they are.. The kids like to move them around!
I do have several poles.. I just have to try and remember where they are.. The kids like to move them around!
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The store I got my paint from is not BM like I thought. It's California paints. I believe that's a decent paint as well... I got the PRIME TOUCH PROFESSIONAL, ACRYLIC LATEX PRIMER / SEALER
I hope that's good enough!
I hope that's good enough!
#32
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While I've heard of California Paints, I don't think I've ever used any or repainted over any that I knew of. As long as the wall is clean, most primers shouldn't have any issues with adhesion. The cheaper primers may require an extra top coat if using a latex enamel in order to get a good consistent sheen. Not saying that is a cheap primer - I'm just not familiar with that brand.
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[Sarcasm]Did I mention how much I love painting![/Sarcasm]
Man does the drywall suck up the primer! It says 400sqft of coverage.. I'm barely getting 200sqft! Maybe I'm being too anal about coverage! Or maybe I should switch to a 1/2" nap.
What should I sand the primer with? 180? 220?
I let the kids use small rollers in the closet!
Now I have a lot more sanding to do there.. but they had fun!
I'm about a little less 1/2 done priming from a pure floor square footage.. But probably more than 1/2 done from a pure coverage square footage. Bedroom, closet, storage room, bathroom, linen closet, hallway are done (priming that is). Just the big rec room with the stairs are left!
Thanks for all the help so far!
Jim
Man does the drywall suck up the primer! It says 400sqft of coverage.. I'm barely getting 200sqft! Maybe I'm being too anal about coverage! Or maybe I should switch to a 1/2" nap.
What should I sand the primer with? 180? 220?
I let the kids use small rollers in the closet!
Now I have a lot more sanding to do there.. but they had fun!
I'm about a little less 1/2 done priming from a pure floor square footage.. But probably more than 1/2 done from a pure coverage square footage. Bedroom, closet, storage room, bathroom, linen closet, hallway are done (priming that is). Just the big rec room with the stairs are left!
Thanks for all the help so far!
Jim
#34
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Bare drywall can really absorb primer
Sand the primer? I wouldn't do that - all the sanding should have been done before you primed
Sand the primer? I wouldn't do that - all the sanding should have been done before you primed
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I've been told by a couple people (even marksr) to sand
Originally Posted by marksr
Once you made sure all the drywall dust has been removed, apply your primer 1st with a roller, then go back and cut in what the roller didn't get. Before applying the finish paint, sand lightly [a pole sander works best] then cut in and then roll a section/wall
#37
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I usually sand the primer on the walls/ceiling - nothing fancy, just a quick scuff sand with 120-150 grit. A drywall pole sander works great for this. This will also help you find any bad spots in the drywall or primer.
I wouldn't get too excited about the closets, once they are in full use - you won't see much of the wall
I wouldn't get too excited about the closets, once they are in full use - you won't see much of the wall
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That's why I let them paint just in the closet!
#39
Marksr:
What benefit would Jbuszkie derive from sanding ALL of that primer that makes it worth his time and labour to do all that work? And, if you've ever sanded latex paint or latex primer, you know it just doesn't sand. You just gum up the sandpaper or sanding screen with latex gunk in the first few strokes, and then you're not sanding any more, but rubbing latex gunk against the wall.
What benefit would he derive by putting himself through all of that?
Mitch:
You know, people are relying on us to give them the best advice we can. That is, the poster's interest should be first and foremost in here.
Jbuszkie:
I have nothing but contempt for the people that answer phones at manufacturer's 1-800 customer service call centers. However, in this case I'm going to encourage you to look on your can of primer and can of paint for either or both manufacturer's 1-800 customer service phone numbers and see if either the manufacturer of the primer or the manufacturer of the paint recommends that you scuff sand the primer before painting.
What benefit would Jbuszkie derive from sanding ALL of that primer that makes it worth his time and labour to do all that work? And, if you've ever sanded latex paint or latex primer, you know it just doesn't sand. You just gum up the sandpaper or sanding screen with latex gunk in the first few strokes, and then you're not sanding any more, but rubbing latex gunk against the wall.
What benefit would he derive by putting himself through all of that?
Mitch:
If Mark says to sand, that's enough for me.
Jbuszkie:
I have nothing but contempt for the people that answer phones at manufacturer's 1-800 customer service call centers. However, in this case I'm going to encourage you to look on your can of primer and can of paint for either or both manufacturer's 1-800 customer service phone numbers and see if either the manufacturer of the primer or the manufacturer of the paint recommends that you scuff sand the primer before painting.
Last edited by Nestor; 06-06-11 at 08:57 PM.
#40
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There is a big difference between scuff sanding latex paint and aggressively sanding it. Sanding almost always promotes adhesion. Scuff sanding the primer on new drywall will also highlight and help you find any defects in the drywall or primer coat. The floors on new construction are never as clean as an occupied dwelling so there is a greater chance that dirt will have been blown into the primer.
I've painted over a 1000 new homes and would not have bothered with this step if I didn't think it was worth it.
I've painted over a 1000 new homes and would not have bothered with this step if I didn't think it was worth it.