Posts Tagged ‘drywall sealer’

Drywall primers… again!

December 20, 2008
DSC_3833aI receive countless emails asking when to use a drywall primer with all the talk today about self-priming wall paints. Many paint contractors commented on my videos on YouTube saying I should use a wall primer on bare drywall rather than applying wall paint directly over it. What do they know that I don’t? So let’s take a closer look at wall primers and their purpose. What is a wall primer supposed to do? (Click any photo for larger views).

Bare Drywall

IMG_0078The objective priming bare drywall is to seal the porous paper and drywall topping (mud) to provide a nice foundation for the paint to bond with. What this means is achieving an ultimate seal and bond with the paint to the porous fibers of the paper and the porosity of drywall mud. We also want the wall primer to produce a solid uniform sheen for the top coat of paint.

Our goal has four parts:

1) seal the porous paper surface
2) provide a surface the paint can bond with
3) seal the drywall mud
4) prevent top coat sheen degradation

What can go wrong using primer:

What if the top coat of paint did not bond with primer? What if the primer didn’t bond with the drywall? What if you had a nice bond to the drywall but not to the drywall mud? What do you do now? You primed right? The paint isn’t sticking that well is it? Did you try the tape test or maybe you tried washing it and the paint and primer came off back to bare drywall? Did you remove the masking tape from the baseboard and it tore the paint and primer off the wall exposing bare drywall?

The label on the paint can says to use a primer. The paint store rep said to use a primer. You read online, you read it in a magazine, you always heard – ‘use a primer’ and you did. You even used the paint manufactures recommended primer.

So now what? Is it too late; you already have a coat of paint over the primer? Was the surface clean? Did you remove all the drywall dust left behind from sanding? Did you shop vac the walls and the paint still didn’t stick? Did you try wiping down the drywall with a damp sponge? Yeah, so did we. Did the primer fail? Yeah, so did ours. Did you do something wrong?

Lucky for you, we have all the answers and before you get discouraged we also have a fix so you can achieve that finish and bond that you initially tried for.

We tested a total of 14 wall primers over bare drywall and not one of them performed as well as a drywall sealer such as Zinsser Gardz. Let’s take a look at why this is.

The Test

2paintYou perform the test yourself. Let’s say for example you have a piece of bare drywall sitting on your lap and 1 tablespoon of water and 1 tablespoon of any wall primer of your choice, there are tons of them out there, pick one. Now, take the tablespoon of water and slowly pour it on the drywall. The water dissipates into the drywall right? Now take the tablespoon of primer and do the same. Not exactly the same result huh?

If you want to dive deeper into testing, try this test over bare drywall mud, it will provide similar results with a completely different effect with the primer.

Do this small test too. Take a sanded drywall patch, clean it, dust it, vac it, damp sponge it if you want and run your finger over it when its dry. I suspect your finger will have a white dusty powder on it.

So what does this test tell us? No matter how well you clean up new board for paint there is only one thing that will prepare it to accept paint. Apply a sealer that will penetrate both the paper and the mud and bond all of it together. Thinner material penetrates better – right?

Click the photo above. Notice the first 24" inches from the corner doesn’t look as nice as the next 24", then you see another 24" that doesn’t look as nice as the 2nd area. That 2nd area that looks best in the photo is 2 coats of eggshell paint over bare drywall. The first 24" is primer plus one coat of eggshell paint.

Sheen degradation

One huge set-back you get from using a primer is top coat sheen degradation. Some primers are better than others but nonetheless, you will lose some sheen that will get absorbed in the primer coat. The loss of sheen is very apparent in the photo above.

proform004Here is a photo of a drywall sealer applied directly over the drywall mudded horizontal seam. You can clearly see how well the sealer absorbed into the mud. The next photo shows what the horizontal seam looks like when you apply one coat of an eggshell paint over it.
proform005Again, you can clearly see the sealed portion of the wall and what was not sealed.

 Primer vs. Paint

Img00970001Think back to a time you applied a coat of paint over bare wood. Do you remember what happens with the paint? Do you recall how much of that paint absorbed into bare wood? Do you remember applying a second coat of paint and it too absorbed into the bare wood, even your third coat looked questionable? (Click any photo for larger views)

Well check this out… the same thing happens when you apply paint over bare drywall. Exactly the same thing but with varied results depending on the paint you use.

There are paints that penetrate bare drywall better than a primer and provide a better bond and also look great when you apply 2 coats over bare drywall. So here we have a classic case of Best, Better and Good options.

The photo above shows a coat of paint over bare drywall (the darker color). The window wall and into the corner is a tinted primer. So you can clearly see some finish paints perform nicely over bare drywall with coverage. The paint used in the above photo outperformed all 14 primers in coverage over bare drywall. How messed up is that? – paint performing better than a primer designed for bare drywall.

Looking at the photo above, would you honestly say a primer is needed over bare drywall if I can achieve both coverage and tight bond with a paint that is far better than if I used a primer? I’m saying… knock yourself out. If you feel that you have the desire to waste money and labor on a primer coat, then do it.

But let’s take a look at what is best because that’s what this site is all about.

Best

eggshellThe best product known to me for bare drywall is Zinsser Gardz and thankfully we have that product because it makes me never want to use a wall primer again. I say this because I see primers fail all the time, hence the abundance of people writing me about primers. Apply Gardz directly over bare drywall and then for best results – 2 coats of paint. Remember this is new board and you need to build a foundation so use 2 coats of paint. Think about this, even with one coat of Gardz, and 2 coats of paint, your total dried mil thickness is still minimal at best.
gardz2Gardz is a thin clear sealer and most of the product will dissipate into the fibers of the board and mud. This product is similar to injecting glue into the drywall and mud. This is why in the photo above you see a very nice uniform finish with one coat of Gardz and one of finish.

Better

UH1412_01aBecause there are paints that I know adhere better than all 14 primers we tested I am going to say straight quality paint is better over bare drywall. The only problem you may experience is a need for a 3rd coat – prime plus 2 coats is a total of three coats anyway but you can achieve better stick this way. Ok, to be fair the other argument to this method is achieving a uniform finish with paint like an eggshell or semi gloss. But think about this, 1 primer and 2 finish is 3 coats too.

In the photo above the long wall is split half way with two different wall paints and the photo was taken after they dried. Notice in the front most left portion how one product covered and dried much nicer than the other closer to the window.

Good

barrington 24 027aThe cheap and less expensive route is using a primer over bare drywall. You have an advantage utilizing this method but it also disadvantages. The advantages are – you can do one tinted coat of primer and one coat of finish but you lose the stick or bond some of us need to tape off walls, hang wallpaper over and even wash or scrub depending on what your paint allows.

Remember when you got the job, she told you she was hanging wallpaper at a later time. So, do you shortcut her at this point or prepare the job for what is to come? What if its you hanging that paper? Too many guys are doing the "right-for-now" work instead of what is best for down-the-road work.

Primer is generally less expensive than paint. So if your intent is to never wash or touch the walls then do this method but what you might find is what you see in the photo. It looks like it needs another coat of paint.

Primer also requires MORE attention to rolling than wall paint. If you roll primer on any old way – you will never get the finish to look right no matter how many coats you stick on it. Here is a clip on rolling. Utilizing the last stroke down method will provide a level of finish that is consistent. The finish in the Best Method was done with last stroke down.

Something to think about

Here is something else to think about for those of you shooting commercial work. Think about how much you can save on materials utilizing a better method. What is that high-build primer suppose to be shot at??? 20 mil thick? That is crazy!!! Actually its ridiculous. If you are shooting walls – you are already wasting materials and damn near twice as much vs rolling it on.

Here is an interesting tid bit. Same two houses done two different ways. One guy sprayed the walls with 60 gallons and the other rolled it with 15. The guy spraying had a guy back rolling too. What a huge waste of time and money and an extra guy. Guy spraying spent $1,380 on materials and the guy who rolled it spent $345 There was no difference in workmanship.

Funny how a certain manufacturer makes an executive decision to create a primer that requires such a heavy layer of it to cover bare drywall. But that same question also begs the question, was a product like that designed because guys don’t know how to paint or does the manufacturer not know how to make a product that works without laying it on so heavy. If you apply anything at 20 mil, it better look good!

The argument

440i My argument with using a wall primer is the lack of a fail-safe method and I need that in my business. While I enjoy the 440i I received from a paint store due to primer failing, I am not going to have another homeowner come back to me complaining she washed the paint and primer off the wall and obviously this has happened to me otherwise I wouldn’t be posting a fix to this problem online. I have a ton of information and previous test on wall primers. Do a Google search on jackpauhl+wall primers or click this link.

The Fix

So let’s say you too fell sucker to the “use a primer” method and you are in that same situation where the paint washes off the wall or you had to apply masking tape to do some wild painting scheme you found on TV. There is a fix and leave it to no other than Zinsser to have your back! Zinsser Gardz can be used to apply over a paint that was previously undercoated with primer utilizing the Good method above. Gardz will assist with penetrating the paint and the primer and help with bonding them to the drywall beneath and not only that but moving forward with a new coat of paint will give you the ultimate finish you see in the Best method above.

Painting highly visible walls

Let’s say you get a call and their house is a few years old with builder grade flat paint on the walls and they want you to paint the 16′ high foyer wall that extends to the back of the house (windows on both ends). You go to the basement and see the left over paint and know putting an eggshell over that flat paint might require a certain degree of finesse to make a highly visible wall look right. Your best bet here is to apply Zinsser Gardz over that flat and proceed with one or two coats of eggshell paint.

How to treat drywall

October 6, 2007

This small article covers what you need to know about painting new drywall. First things first, our goal is to get the best finish results with an eggshell paint. Generally flat finish paints do not require much of any new drywall surface prep.

In order to achieve the best results with the level of sheen we are going to apply a drywall sealer. The sealer as opposed to primer will in fact absorb or penetrate the porous surface of the drywall and seal down the surface like no primer can.

The photo on the left is the result of Gardz applied to new drywall with one coat of ICI Dulux 1410 Low Sheen Eggshell paint. This photo was taken 2 hours after the wall was painted. The wall paint is almost every bit as wet when I rolled it. Another benefit to using Gardz is your finish paint sticks better. Because Gardz absorbs into the surface of the drywall, you get the best stick or adhesion in comparison to using wall primers which typically dry on the surface of the paper.
The photo on the left is without the Gardz treatment. Notice the dry patchy area where the drywall mud can be seen through one coat of ICI Dulux 1410 Low Sheen Eggshell paint. Click any photo to view larger detail.
This photo on the left captures a better perspective as to the lack of a drywall sealer. You would think a wall primer would allow you to achieve a uniform paint finish but that is generally not the case with primers.

I can see one of my readers going to Home Depot and asking for a drywall Sealer. The HD associates would be like, "What? No you want a primer… who told you that you need a sealer? – that’s silly".

UPDATED: Gardz applied to new drywall will turn the drywall a darker grey. You should be aware that some paint colors will not cover the same over a dark grey such as pastel colors.