Posts Tagged ‘priming’

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.

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PrepRite ProBlock B51 20 W

March 7, 2008
I’ve been spending more time with some Sherwin Williams product lately. I typically do not use their products but I do like to keep my hands on what they’re up to. I grabbed a gallon of the PrepRite ProBlock Seals & Bonds primer for priming pine Anderson Windows and I was very happy with the results.
My goal here is to apply a tinted primer which was 65% of SW Cloud Nine and top off with two coats of Sherwin Williams Master Hide Semi-Gloss. The working time and coverage is superior for this application.
The photo looks slightly purple because it’s tinted. I like when things go well and this project went without a hitch. The primer is thick enough to bridge with but use caulk instead. Pro’s don’t bridge anything!

I used the new Purdy Clearcut nylon/polyester brush as seen. Click photos to view larger images.

About MDF Trim

October 21, 2007
Who cares how MDF is made – let’s just skip to how to paint it. Think of MDF trim as a super stiff smooth sponge. If you place a piece of MDF trim in water it will pucker up to the point you may not recognize it, no joke.

Let’s say you put MDF in your bathroom and the water from the shower drips onto the floor with a puddle near the baseboard. MDF if not properly primed and painted will absorb that water and the baseboard will be destroyed. It’s really as simple as that.

Another scenario, let’s say your basement floods and your baseboard and trim gets wet, your MDF trim is ruined. It’s as simple as that.

So, if you know your MDF will come in contact with water (melting snow from boots) or (spill something in the kitchen), your MDF MUST have an oil based primer applied to ALL edges, front, back, top, bottom, the saw cuts, everything or you leave yourself open for damage to your investment. It’s as simple as that.

If your trim or molding is already installed, well then you learned a valuable lesson just now, if it’s not installed, take the time to dry cut your pieces and prime the pieces entirely with an oil-based primer. Do this for any area you feel might come in contact with water even 1 table spoon of water will destroy MDF. DO NOT think for a second putting oil-based primer on the face of your MDF will prevent any damage from water, it won’t.

The theory of MDF is to save the consumer or builders money but in fact, finishing MDF costs more than if you simply bought pine trim which is a hell of a lot more durable than MDF. Pine trim while still not the preferred trim of choice at least won’t chip apart when you whack it accidentally with the sweeper or pull the cord hard for that matter. Dogs love MDF too!

About the photo: Water damage on MDF from the carpet cleaner who dripped a little water on the floor. Sure he wiped up the spill but the water was underneath the baseboard and this is in an area where no water was expected.

See also: Painting MDF and issues with filling nail holes on MDF

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ProForm Compound Issue

April 30, 2007

We currently have an issue and looking for a solution to painting over ProForm joint compound made by National Gypsum. We have two drywall finishers and they use ProForm Lite and ProForm Topping products.

The problem we are experiencing pertains to applying eggshell paint over their finish work. We have two separate issues. One is the paint absorbs excessively into the horizontal joints but not the patches made over screws.

The problem we have with the patches over screws is the opposite. The paint does not seemingly absorb at all (see photo #2), resulting in a shinier area over the patch and even with 2 coats of eggshell, the patched areas become noticeably shinier than the rest of the wall even when a wall primer is used.

Here is what we tried so far. We applied the following wall primers to the bare drywall with varying results and in most cases, worst results vs. painting eggshell directly over bare drywall.

1) ICI 1010 Prep & Prime Stain Jammer
2) ICI 3210 Prep & Prime Gripper Multi-Purpose Primer Sealer
3) Kilz 2
4) Sherwin Williams PrepRite Classic Primer
5) Zinsser Bulls Eye Water-Based Primer
6) ICI Dulux 1000 Prep & Prime Hi-Hide Wall
7) Sherwin Williams PrepRite® High Build Interior Latex Primer/Surfacer (what a mess)

We tried all of the primers above with 2 coats of eggshell paint for finish. Most primers enhanced the screw patches making them stand out shiny.

Today we applied Zinsser Gardz to the horizontal joints as seen in the top photo and this photo. The Gardz worked very well sealing the horizontal joints. We applied Gardz to a few patches over screws and it appears at this time it may work.
This photo shows a close-up of Gardz over the horizontal joints and how it dried over the mud.
This photo shows one coat of eggshell over the bare drywall with Gardz placed only on the horizontal joints. This is what we expected any of the 7 primers to do to the joints. I will let the 1st coat dry a few days and try 2nd coating an area to see how it dries down. At this point, we tested about 10-12 different eggshell paints with this issue. More to come…

Additional info: If we were to take USG Topping and make a new patch over the existing patch in the (blue wall photo) above and repaint the new patch, problem solved. I am unable to find any help on this topic. I wrote National Gypsum 4 days ago and no reply. None of the drywall finishers I know use Proform so there seems to be a lack of experience with the product.

Wall Primers UPDATED

April 20, 2007

I have two additional primers tested to add to the previous post on Wall Primers Tested.

The following primers were tested as outlined on the previous post with the same or similar results. Basically, now 7 primers tested in comparison to 2 coats of ICI Dulux 1410 Eggshel paint over bare drywall.

6) ICI Dulux 1000 Prep & Prime Hi-Hide Wall
7) Sherwin Williams PrepRite® High Build Interior Latex Primer/Surfacer (what a mess)

About the Photo
One coat of 1410 applied to bare drywall and sanded excessively for the second and final coat. The second coat was applied today. I will post the photo on Monday.

Synthetic brushes with Oil

April 20, 2007

We all know that any decent brush can get the job done but it doesn’t necessarily mean the job will turn out nice. Synthetic SRT (Solid Round Tapered) filament brushes are proving to be more beneficial in the workplace over china bristle with oil-based products. It seems not long ago the majority of our materials spread on jobs were oils, today, we only use a few.

Priming is a key component to determine what the outcome of the job will be. The final outcome of finishing anything will fall back on what’s under the finish coat and how it was prepared. For those of you who like to produce quality finishes you know that means the primer coat better be smooth and we all know that means sanding endlessly until it is.

To minimize our sanding efforts to produce quality finishes in less time we turned to spreading oil-based primers using nylon/polyester blend brushes with precision flagging which ultimately will reduce brush marks and improve leveling performance. A quality SRT brush used with a quality primer will save you time on the job.

About the Photo

Oil-based primer applied with a nylon/polyester brush over pre-primed finger jointed wood. The photo was taken immediately after a brush stroke, leveling is easily achieved. Click photo to enlarge.