Posts Tagged ‘bubbles’

Activating Adhesive on Pre-Pasted Mural Wallpaper

March 20, 2022
Mural panels standing on edge are cut, sequenced, staged, and ready to be pasted.
The panel lying on the floor will be my last strip, and will need to be measured and trimmed narrower before it’s ready to be pasted or hung.
I use several different methods to paste pre-pasted wallpaper, and you can do a Search here to read more.
But for today, I’m using the tried-and-true historic method of running the strip quickly through a water tray .
At the top of the photo, several strips have already been submerged and pulled through the water, then folded pasted-side-to-pasted-side. This is called booking .
Booking allows the adhesive on the back of the wallpaper to absorb the water and become activated. And it allows the wallpaper substrate to absorb moisture, expand, and then contract a little.
This method can sometimes get the material a little too wet, which can lead to over-expansion and then bubbles on the wall. That’s why I’ve placed the booked strips at a slant and over the bucket – so excess water can drain off.
Usually I paste and book one strip and then paste and book the next strip. While I’m hanging one, the second one is booking and waiting its turn to be hung. But with this water tray method and certain brands of pre-pasted material, such as Anewall , York , or Sure Strip , the paper sometimes gets so wet that it needs more time to dry before attempting to hang. So I’m pasting more strips at a time, so they can be drying out a bit while I hang the first strips.
There’s a bit of a risk to this, which is the potential for the paper to over-expand as it sits wet waiting to be hung. Then once it’s on the wall and starts to dry, it can shrink. All wallpaper shrinks when it dries. But if it has expanded too much, then when it dries and shrinks, you can be left with small gaps at the seams. Again, gaps are common with all wallpapers (most all), but can be exaggerated when dealing with over-saturated pre-pasted material as it shrinks.
Back to the method … You see the water tray, filled 3/4 full with clean water. I’ve set it on towels, which are in turn set on top of a thick plastic clear shower curtain. And that’s on top of my usual dropcloths, which are absorbent on the top (blue) side and water-proof on the underside. All this keeps any splashed water from getting onto the clients’ floors.
I also sometimes set the water tray in a bathtub, with towels set over the edge of the tub and on the floor.

Hanging Pre-Pasted Wallpaper

March 8, 2022
Pre-pasted papers come with a thin layer of adhesive on the back. In the old days, we ran the paper through a water tray or trough to activate the paste. I’ll still do that sometimes these days, and also roll a very thin layer of paste onto the wall before hanging the strip.
Alternately, current instructions suggest using a squirt bottle to mist the back side of the paper, wetting enough to activate the paste. That sounds like a whole lot of squeezing and pain in the wrist / hands to me! Additionally, I don’t believe that it will give even coverage of the water.
Instead, I’ll take a small amount of paste from my bucket and roll a very light coat onto the back of the paper. The paste isn’t really needed, but I like the extra assurance.
It’s important that the manufacturer’s adhesive be wetted sufficiently and become activated, so next I’ll take sponge and used it to drip on clean water from a 1-gallon bucket I have sitting on the edge of my pasting table. I sprinkle the water over the back side of the wallpaper, then use my paste roller to gently spread the water over the surface.
This activates the paste, and also allows for the substrate to absorb moisture and fully wet-out . Then the paper is booked (folded pasted-side-to-pasted-side) and set in a plastic trash bag for a few minutes, to allow the paste to become activated and for the paper to expand. If you don’t wait the right amount of time, you will end up with paper expanding on the wall – and that means bubbles and blisters.
To speed the install process, you can paste your next strip while the first one is booking in the trash bag.

Fixing Drywall Damage From Where Vanity Was Removed

January 20, 2022
The powder room in this 1990’s home in the Houston Heights is being updated, and that means replacing the wall-to-wall vanity. Here the vanity has been ripped out. The areas where the backsplash was adhered to the wall have pulled the top surface of the drywall off. In addition, the plumber had to cut out a section of drywall in order to gain access to the pipes, so he can install the new faucet and handles. You can see the connections roughed in.
You can’t hang wallpaper over this mess. First of all, it way too uneven – all those bumps will show under the new wallpaper. And the outline of the ” trapdoor ” will leave a big square ridge under the paper. Thankfully, the plumber secured the panel with drywall screws – most plumbers just leave you with a chunk of drywall floating in space, or even just an empty hole.
Back to patching issues … in addition, the torn areas of drywall will absorb moisture from the wallpaper primer and / or paste and expand, creating bubbles that will show under the new paper.
I needed to fill in dips and gouges, even out high areas, and prevent bubbling drywall.
Gardz by Zinsser to the rescue! This is a penetrating sealer that soaks into porous surfaces and then dries hard, binding them together and creating a stable surface, as well as resisting moisture from water-based top coatings.
This picture doesn’t look much different, but here the torn drywall is a little darker, indicating that the Gardz has soaked in and dried. The surface is now ready for a skim-coat.
But first, the trap door needs to be addressed. I covered the cut areas with four strips of self-adhesive mesh drywall tape (no photo).
Then I went over everything (wall to wall) with joint compound (commonly referred to as mud ) (no photo).
Because of the thickness of the high and low areas, this had to be a thick coat of smoothing compound, and would take a long time to dry. So I went to the jobsite two days ahead of our install date, to do these initial repairs.
And – no – you can’t use quick set or hot mud or 5 or 20 minute mud to do these repairs. These products are intended for repairs of small areas. Top coatings like primers, paint, and wallpaper paste do not stick well to them. Don’t let a contractor sweet-talk you into letting him use any of these to smooth a large area of wall.
Here is the wall after my first, heavy, coat of smoothing compound. I use Sheetrock brand’s Plus 3.
The bubbles you see just left of center show that Gardz didn’t 100% do its job of sealing out moisture, as a little expansion and blistering has occurred. Not a biggie. These will disappear when the surface is sanded. There is usually not a problem with these re-appearing.
When I got to work two days later, the smoothing compound had dried. I sanded pretty smooth. Then vacuumed up the dust on the floor, and then used a damp sponge to wipe residual dust off the wall. This is important, because no coating will stick to dust.
The wall still wasn’t perfectly smooth, so I did another skim-coat. This was much thinner, so didn’t need a lot of time to dry. I used a fan and my heat gun to speed things along.
Once that was dry, I sanded it smooth, vacuumed and then wiped off all dust. Then rolled on my favorite wallpaper primer Roman Pro 977 Ultra Prime. I have the paint store (Murphy Brothers in central Houston) add a little blue tint, so I can see it when I apply it to the wall.
What a transformation! Now this wall is ready for wallpaper!

Strange Bubbles in Drying Wallpaper

September 21, 2021
Air bubbles appearing as this wallpaper dries.
Smoothing brush, and plastic smoother.

It’s not uncommon for vinyl wallcoverings to develop bubbles as the paste dries. This is called “off gassing” and it happens because the vinyl is impenetrable and there is nowhere for air to escape.

But these days, most paper products – such as this one – allow air to pass through, and dry nice and flat with no bubbles or blisters.

One thing to keep in mind is, virtually always, these bubbles will disappear as moisture evaporates and the the paper and paste dry and shrink taught. So the less fiddling you do with it, the better. (And exception would be large bubbles, which should be addressed.)

One way to treat bubbles is to chase them out toward a seam, using a tool such as the plastic smoother. You can also use a pin or razor blade to poke a tiny hole in the paper to let the air escape. It helps to do this in a part of the pattern, and not in an unprinted area, to disguise the hole.

I also like to understand why something like this happens. If you know what caused it, you have a chance of preventing it the next time.

I primed the wall with my usual primer, so I don’t think there would be issues with moisture being trapped between the primer and the wallpaper. But then again, you never know what is inside the wall – many walls have been painted multiple times, and some layers may not be compatible.

Another cause could be the plastic scraper. The bristled smoothing brush uses a more gentle action to push the paper into place. The scraper could actually overwork and stretch the paper. In fact, if you use the scraper to try to push bubbles out to a seam, you end up creating more bubbles.

I use the plastic smoother mostly for seams, and not so much for smoothing a full strip into place. But it’s possible that I used it more than usual this time, and stretched the paper, creating conditions for the bubbles to form. In fact, on one strip, I gently pulled the bottom portion away from the wall and then put it back in place, but making sure to use only the bristle brush. This did eliminate the bubbles.

But, again, if you just wait it out until the paper becomes thoroughly dry, nine times out of ten, all the bubbles will be gone by morning.

Run Numbers – Re Previous Post

May 15, 2021
Run numbers are important!

Re my previous post, before I visited, the homeowner had purchased 8 rolls (4 double roll bolts) of paper. This was just exactly enough (12 strips) for the headboard wall, but I told him to order 16 more to do the rest of the room. The new paper came in a different run. So we had Run 16 for the headboard accent wall, and Run 17 for the other walls.

(You can’t mix runs on the same wall, because different runs, printed at different times with different batches of ink, will be slightly different shades. This very slight color difference will show up on the wall as a striped or “paneled” effect.)

The wallpaper is by York. It is a non-woven material, comprised of synthetic fibers rather than wood and cotton. The synthetic material does not expand when wet with paste, which means the wallpaper can be hung via the paste-the-wall method, with no “booking” or “soaking” wait time needed.

Interestingly enough, Run 16 behaved differently from Run 17. I hung the accent wall with Run 16 quite successfully using the paste-the-wall method.

But when I started the next wall using Run 17, bubbles and wrinkles developed. The paper was absorbing moisture from the paste and expanding on the wall, creating the small bubbles. Quite unexpected with a non-woven material.

The solution was to paste the back of the wallpaper, rather than the wall. This allows the material to absorb moisture and expand a tad before you get it to the wall, so it will behave itself once it is on that wall.

Unlike a traditional paper, this non-woven material did not need a lot of time to absorb moisture, but could be pasted and hung immediately. This greatly speeds up the installation process.

Pasting the paper has an additional advantage in that it renders the material more supple and pliable, which makes it much easier to work around corners or manipulate into position in tricky areas.

Whoops! Someone Painted Over Old Wallpaper

April 21, 2021

Just looking at the walls, I had not noticed . But when I removed the light switch cover, it was clear that someone didn’t bother to remove the old wallpaper, and just painted over it.

Actually, they probably did do some prep, because you could not see seams under the paint. They must have taken steps to cover the seams.

And there was no flashing … difference in texture between paint over wallpaper, for instance, and paint over smoothing compound that was used to disguise those seams.

And there were no bubbles (caused by latex paint on top of wallpaper that absorbs moisture from the paint and swells) and only a few tiny loose areas.

Still, it would have been better if the previous guy had put some effort into removing the wallpaper, and then washing the paste off the wall and then sealing with a stain blocker, to prevent paste residue from causing the new paint to crackle and flake off the wall. Then the room would be adequately ready for paint.

Realistic, Textured Faux Brick Wallpaper Accent Wall

April 8, 2021
Textured wall skim-floated smooth, primed, and ready for wallpaper.
Starting in center to balance off-level ceiling line.
Pretty realistic!
The material has a slight texture, although it’s not visible in this photo.

Originally, the homeowner, a single guy in the Houston Heights, had a sort of Asian theme in his master bedroom. But he was ready for something more guttural and free form. Mission accomplished!

The new look is a little bit Industrial Modern, and a little Back Alley. 🙂

He has a lot of sports memorabilia, and I think that would look great hung on this faux brick wall.

The ceiling line was not level at all, which means that you can expect the bricks to not line up perfectly straight across the wall at the ceiling. Bricks would be taller on one end and cut shorter at the other end.

And so I started hanging in the middle of the wall, butting my strip up against a plumb line from my laser level. Moving across the wall, as the ceiling line starts to track up or down, by starting in the middle, you even out any wobbling of the pattern at the ceiling by spreading half of it on the right side of the wall and half at the left side.

As it turned out, the bricks stayed perfectly straight across the ceiling line.

This is a lightly textured, embossed vinyl product by Akea, a British company. I was really expecting a non-woven paste-the-wall substrate. But this was on a paper backing, which you don’t see often these days, especially with the European manufacturers.

It was thin and flexible, the seams laid down nicely, and no bubbling (bubbles are pretty typical with paper-backed vinyl goods).

Minor Bubbles, Waffling, Quilting on Wallpaper

March 28, 2021

A lot of high-end wallpaper manufacturers use heavy inks (a.k.a. stinky ink). When wet paste is rolled on to the back of the wallpaper, these inks commonly compete with the substrate for moisture. The substrate absorbs more moisture and more quickly than the inked areas.

The result is wrinkles, blisters, bubbles, warps, quilting, waffling – whatever you want to name it, you’ve got a bumpy surface that doesn’t want to lie flat on the wall.

One way to tame this beast is to LIGHTLY sponge water onto the surface of the paper, before pasting. This allows the front to absorb moisture at the same time that the backing is soaking up moisture from the paste. The result is a more even “quilting” of the material.

Another thing to keep in mind is that small blisters like seen in the photo will usually flatten out and disappear as the wallpaper paste dries. A good wallpaper-specific primer underneath is a big help.

Also, a liner paper is often a good choice. The liner is a special, unprinted paper that goes under the decorative wallpaper. The liner absorbs moisture quickly and helps “lock down” bubbles and seams.

A liner also ups the installation price. Because you have to add the cost of the material, plus the labor of at least an additional day to hang the liner, and then let it dry at overnight or longer.

Challenges With 40″ Wide, Thin Vinyl Mural

March 13, 2021

See other recent post(s) for more info on this material and its install.

When ordering, from the materials offered, the homeowner chose this vinyl option, because she loved the slightly textured, “pebbled” surface. I would have much preferred she went with the more predictable and cooperative non-woven material.

The instructions said to paste the wall. Which is what I did. But I believe this material would have performed better if they had said to paste the product.

Pasting the product would have evened out moisture absorption from the paste, as well as expansion as the substrate wetted-out. That may well have eliminated the wrinkles you see in the photo.

It took a lot of patient work with both the smoothing brush and the plastic squeegee to work these wrinkles and bubbles out of the wallpaper. The resulting flat surface was not necessarily the Holy Grail … because often the far edge of the wallpaper will get distorted and / or warped / bowed.

It’s really difficult to hang a new, subsequent strip next to a strip with a warped edge. It’s hard to butt the seams, and plus additional strips get more and more warped. Eventually, you get to where the resulting wrinkles are so large that you cannot work them out.

This is one reason why you start hanging from the midpoint of the wall. This helps disperse any such wrinkles or other imperfections equally across both the right and the left sides of the wall.

I was lucky that I had only four panels and three seams on this install.

As mentioned above, a non-woven substrate would must surely have eliminated the wrinkle problem. Non-wovens are made of synthetic fibers (including fiberglass), so they do not expand when wetted by paste or water. So you can paste the wall and then apply the wallpaper, without worries about the paper stretching out of shape

Weird Bubbles Develop on Wall

January 21, 2021

This wall had a slight texture that needed to be skim-floated and then sanded smooth. After I applied the smoothing compound (drywall joint compound), a half hour or so later, these tiny blister bubbles appeared. This is off-gassing. But from what is a mystery.

The only clue is that this area is around where the hand towel was positioned next to the sink. So this area would have received a lot of splashing of water and also soap and other toiletries.

My guess is that some of these substances stuck to the wall. And for whatever reason, when they were covered by the joint compound, they released air / gas, which caused these bubbles.

I’ve seen this before. But this time, some of the bubbles were large enough that they did not sand down smooth and even with the wall surface. So I had to do a light touch-up skim-coat on top.

Once I got the wall smoothed, I wasn’t too concerned. I don’t believe that anything causing these tiny blisters would be something that would bleed through and stain the wallpaper.

Some substances do stain wallpaper, though. For more on that, do a Search here.