Posts Tagged ‘blisters’

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.

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.

Dark Papers – Visible Seams

September 10, 2019


Wallpaper is paper, and when paste is applied to the back, the paper gets wet and expands a little. When it hits the wall, it dries – and often that means it will shrink, even if just a tad. That will leave minute gaps at the seams. If the paper is dark and the wall or the substrate are light , you will most likely see white gaps at the seams.

Some manufacturers combat this by printing dark patterns on a darker substrate. This is what you see in the photo above. But it also helps to color the edges of the wallpaper with a corresponding color of chalk. (You can’t use ink, because ink will bleed and discolor the wallpaper.)

Sometimes you can go back and color in the seams with hobby paint or chalk, which sounds simple but actually takes some technique and finesse, to color the areas adequately and avoid staining the paper.

Painting the wall the color of the paper is a thought, but not as feasible as it sounds, because wallpaper wants to stick to wallpaper primer, not paint. And I’ve seen paint lift off the wall when the wallpaper dried and put tension on it – so, not using that trick again.

Paint with a clear wallpaper primer over it is another idea – but it adds an extra day (or two) and more labor and material costs.

What I did in this case, was to try different pasting methods. This wallpaper, from the Historic Homes Collection by Thibaut, is pre-pasted and engineered to be run through a water tray to activate the paste on the back of the paper.

This method works super with most of their colors. But, because the water tray adds a lot of moisture to the wallpaper, the amount of expansion and then shrinkage results in tiny gaps at the seams – not a big deal with a white or light-colored wallpaper. But with this black paper, it was showing too much white at the seams. Yes, a 1/64th” is too much, when you are looking at white between black.

So instead of running the paper through the water tray, I experimented with pasting the back of the paper. I knew this method would allow the paper to expand less, dry faster, and shrink minimally.

But wallpaper that has a thin layer of pre-paste on the back does not respond well to the installer applying paste to the back on top of the pre-paste. You are greeted with a thick, dry, gummy mess that is hard to manipulate on the wall.

There were also a lot of bubbles and blisters under the surface. Yes, you can be assured that these will disappear as the paper dries – but it sure makes you nervous while you are looking at them!

Spraying the back of the paper with water from a mister didn’t work, either, because the spray bottle spread water unevenly, water sloshed onto my work table, and there was nothing to enhance the “stickiness” of the manufacturer’s pre-paste.

After experimenting, what worked best was to apply paste to the back, full strength, and then quickly spritz the back with water and roll it around, to thin down the paste I had just applied, and to add enough moisture to activate the pre-paste.

The wallpaper strips with this pasting concoction were thick and muddy and difficult to maneuver, but the drier paste did lock down at the seams more quickly. I didn’t have issues with shrinking or gapping seams after I started using this pasting method.

Do Bubbles Mean Trouble?

May 20, 2019

The walls in this dining room in a historic house in the Houston Heights had received many coats of paint over its 100 years. The latest was a coat of what appeared to be flat latex paint. Since this is not a suitable surface for wallpaper, I applied a wallpaper-specific primer.

I was surprised to see that, a few minutes after I rolled on my water-based wallpaper primer, blisters appeared.

I thought they would disappear as the primer dried, but they did not.

Obviously, the moisture in the primer was soaking into some of the layers below it, and causing something to expand and “off-gas”, which created the bubbles.

I switched from my wallpaper primer to a penetrating sealer called Gardz (also water-based) – and the same thing happened. (The Gardz dried so glossy that I feared the wallpaper would not stick to it, so I went back to my original Ultra Prime by Roman’s.)

Once the primer was good and dry, I used a stiff putty knife to knock off the high points of the blisters. The areas were not perfectly smooth, but they were OK for use under this particular wallpaper.

I’m doing some research, and am hoping to gain insight as to why this blistering happened, so I’ll know how to prevent it in the future.

Stroheim Playful Geometric – A Tough Hang Today

March 24, 2019


This colorful and playful geometric pattern went in an elevated “nook” in an open play area in a new home in the Oak Forest neighborhood of Houston. It wakes up an otherwise all-white house, and coordinates perfectly with bright artwork in the room.

The paper is by Stroheim, and was somewhat difficult to work with, especially in a room that presented the challenges it did – wide window, and four cubbyholes around three fixed built-in shelves.

First, the paper had a selvedge edge that had to be trimmed off by hand, a straight edge, and a razor blade. This is tedious and took about an hour to trim eight single rolls.

Second, any time you have wallpaper whose ink smells like mothballs, you know you are in for a tough day. The ink absorbs moisture from the paste at a slower rate than the substrate, so the paper backing puckers (called waffling or quilting). This doesn’t go away, even after booking and sitting in a closed plastic bag for several minutes – so you end up with wrinkles and blisters on the wall.

One thing that helps with this is lightly wetting the surface of the paper with a damp sponge. This allows the ink to absorb moisture, and relax at the same time the paper backing is expanding and relaxing.

You will also notice in the photo that the edges of the paper are curling toward the front. This is, again, the result of uneven absorption of moisture from the paste. Unfortunately, this continues once the paper is on the wall. I had to keep going over the seams to make sure they were down and that edges were not coming away from the wall. No matter how much paste I put under the seams, or how tacky I let the paste get, it didn’t seem to want to grab those edges.

Once the paper is good and dry, though, usually the seams lie down nice and flat, and any blisters or wrinkles will disappear.

Clay-based paste has less moisture content, and could possibly help reduce the waffling. I hate clay paste, though, because it’s hard to wipe off woodwork and off the surface of the wallpaper, and because it works its way through the paper and casts a tan tinge on the paper.

One thing that will help with issues like these is a liner paper. A liner is a plain paper of a special material that is applied to the wall before the decorative wallpaper goes up. It’s job is to absorb moisture from the paste, which causes the paper to dry more quickly, and to “lock down” the seams quickly. So a liner has its place, but it does add an extra day of labor, plus the cost of the liner material.

Interestingly, the Stroheim instructions did not spec a liner; only a good quality wallpaper primer (which I did use). They also did not spec clay-based paste, but recommended three different types of clear pastes (vinyl, wheat, or cellulose), each of which is distinctly different and contains different moisture contents. I would think wheat or cellulose to be too thin and weak to adequately adhere this particular material.

I’ve hung plenty of their products and had no problems with waffling or curling seams; it’s clear that the company has a blanket set of instructions that they stuff into every roll, with no regard to the substrate it’s printed on or the type of ink that was used.

The other thing is, most of the time, you don’t know what you’re going to be working with until you show up at the job site. Even if you research the brand and pattern number ahead of time, there will likely be no mention of the type of substrate or the “mothball” smelling ink. If I had known, I would probably have suggested that this homeowner use a liner. Beyond that, it’s good to have your truck stocked with a variety of primers and adhesives.

Back to the difficult room … I always say that a window like that is easy for you to look at, but very difficult for me to get paper around, at least while keeping the pattern straight and properly lined up. That’s because papers stretch and twist when they get wet with paste, and can contort out of whack. And the wider the obstacle you are working around, the more the paper can go off-kilter. So you can start perfectly lined up on the left of the window, but by the time you get to the right side, the strip coming down from the top of the wall may not line up with the pattern coming across horizontally below, and the two edges may not butt up perfectly, either.

It didn’t help that the pattern had an irregular hand-drawn look, so I couldn’t use a ruler to make sure every horizontal line was equidistant from the window molding. So that window wall took about two hours in itself.

Then there was the wall on the right, with the four cubbyholes in between the three shelves. I had to get two strips of paper on the backs of each of those cubbies, keep the seams from curling, and keep the pattern straight, continuing to four more strips on the wall to the right (the inside side of the wall you see on the right of the photo next to the door molding), so that all four of those strips would line up with one long piece coming down from the ceiling. Oh, and did I mention the extremely unlevel ceiling? This wall in itself took about three hours.

Actually, the irregular hand-drawn look of the pattern helped immensely, because the pattern didn’t have to line up exactly perfectly. Also, the way it was printed on the paper, the design motifs didn’t cross a seam, so that allowed me to raise or lower a strip slightly, to keep the pattern where I wanted it, without disrupting the look of the design. In fact, it was possible to not follow the correct pattern match, and the eye really couldn’t detect it. I could also cut strips vertically to narrower widths, to suit the area I was working in.

There were a few other tricks I pulled out of my hat, in lining up the design after coming around the window and shelf walls, to plumb up the pattern after turning a corner, and to disguise the very unlevel ceiling. The kill point (last strip meets up with first strip) turned out amazingly undetectable, with very little tweaking from me.

In the end, the nook turned out fantastic, and is ready to host children’s performances, reading marathons, or just gazing out the window.

The interior designer for this job is Stacie Cokinos, of Cokinos Design. She works mostly on new builds and on whole-house remodels, and is a great resource for finding and coordinating all the details – tile, plumbing and light fixtures, rugs, furniture, lamps, accessories, paint colors, and, of course – wallpaper. 🙂

Change Perspective, Change Dimension

March 20, 2019


When looking at this wallpaper pattern from a reasonably close distance, it looks like elongated diamonds. But look at it in an alcove from a distance, and you see a horizontal striped effect.

A good reason to always look at the pattern in a room-set photo before purchasing, so you can see what it looks like played out on a full wall.

Either way, I like it. And it really makes this tall room look taller.

This wallpaper is by York, in their SureStrip line, one of my favorite papers to hang. It’s a thin non-woven material, is designed to strip off the wall easily and cleanly, and comes pre-pasted. This time, instead of their silly squirt bottle suggestion (which provides splotchy and inadequate coverage), or rolling diluted paste onto the back (which reacts with the pre-paste and forms a thick, gummy mess that dries too fast and traps air bubbles), I used the old-fashioned water tray method. I find this wets the paper and the paste better, and makes for a smooth surface, and the paper does not dry out before I get it to the wall (as it does when pasted the traditional way). I then rolled a thin layer of paste on the wall, to augment the pre-paste, eliminate blisters and bubbles, and reduce the chance of shrinkage.

This powder room is in a new home in the Timber Grove neighborhood of Houston. The interior designer is Stacie Cokinos, of Cokinos Design. She works mostly with new builds, or with homes undergoing major renovations. Her look is clean and open and calming … and I am seeing a little farmhouse look creeping in here and there.