Posts Tagged ‘clay based’

Mysterious Spot on Wallpaper – Air Borne Substances

January 3, 2019


If you look closely, you will see tiny tan dots all over this wallpaper. This is a paper wallpaper with a very light acrylic coating, that was installed maybe 30 years ago. The installer did a very good job – although he did not remove the previous layers (2!) of wallpaper backings, and did not use a primer.

I see spots like this almost exclusively in bathrooms – where you have enclosed spaces, toiletries, and humidity.

Since these dots are most prevalent around the upper areas of the room, I think they are stains from air-borne substances. However, an alternate theory is that they could be stains leaching through from the tan backing paper that was left on the wall, or possibly from the clay-based paste that was used for the installation.

Epounding:

My theory of air-borne substances is that if you spray something into the air, such as hair spray, air freshener, deodorant, or even onto a surface, such as glass cleaner, some of the substance becomes air-borne, hangs in the air, and eventually will come to rest on the walls. This results in perfectly round little specks on the walls. (See the Page to the right, “Care and Feeding of Your New Wallpaper.”

The stains could even be coming from cooking oils that splattered into the air, got sucked through the A/C ducts, and expelled into the bathroom.

Since this paper has just a light acrylic coating and no durable protective vinyl coating, most any substance floating around in the air would be able to land on the paper and penetrate into it, leaving these spots.

Don’t get me wrong – I MUCH prefer these thin acrylic-coated papers over thick vinyls and non-wovens. You just need to take appropriate steps to protect them.

Moving on…

Another possibility is because the installer didn’t remove the previous layer(s) of manila-type paper backing left from the original wallpaper installation(s), nor did he use a primer or sealer, it’s possible that chemicals from the old tan paper backing are leaching through onto the new wallpaper.

This is why art framers recommend acid-free mats and framing techniques. The same are available for wallpaper installations – but we’re getting into some pretty high-end topics now…

Getting back to our bathroom in Tanglewood (Houston).

Another very possible cause is the clay-based paste that was used to hang the wallpaper. I have seen many, many times, a “dirty,” tan discoloration coming through from underneath the paper, which I firmly believe is coming from the tan-colored clay-based paste that many installers like to use. I have many instances validating this theory.

The only discrepancy is that stains from the paste working their way through the wallpaper would not manifest as tiny, perfectly round specks, but as more generalized, mottled areas. Unless, the composition of the wallpaper included teensy dots in the paper fibers, intended to allow for porousity. Or humidity in the room forms miniscule droplets which land on the wall and then wick the tan paste up through the wallpaper. Which sounds reasonable to me. In fact, I like this theory a lot. And I really DISlike clay-based paste.

A final idea is that the wallpaper is just old. After 30 years on the wall, materials are bound to break down, humidity will take a toll, and it will be time for a change to a fresh new look.

Bottom line: Remove old wallpaper, properly seal and prime the walls, avoid clay-based pastes and instead use a clear wallpaper adhesive.

Check back tomorrow for more!

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Stripping Vinyl – Again

April 25, 2018


The original wallpaper put up in the early ’90’s was the then-popular “satin” or “moray” shiny, slightly textured heavy vinyl material, with – to crown it off – boring stripes in a lackluster color. Before the new classic damask pattern can go up, the old paper needs to be removed. Here are some of the steps.

Stripping wallpaper is a matter of separating the layers, soaking the backing, and removing the backing from the wall. In the top photo, you can see that some of the colored / striped white vinyl layer has been pulled off the wall. It leaves behind a gritty-textured, yellow manila paper backing, still stuck to the wall.

Don’t let anyone smart-talk you into believing that it’s OK to leave this paper backing on the wall. The truth is, if you put new paper on top of it, the moisture from the paste will soak into the substrate left on the all, and will most likely cause bubbling of both layers.

Back to the top photo. Once that vinyl layer was stripped off the wall, I used a large sponge and a bucket of hot water to soak the backing left on the wall from each strip. This process is drippy, so I protected the baseboards and chair rail with absorbent, water-proof strips. In the photo, you can see the color change of this paper backing, as it becomes saturated with water it darkens and the paste behind it begins to soften.

In the second photo, the paper backing is entirely wet, the paste has reactivated and loosened, and the paper is easily peeling away from the wall, in one tidy intact piece. The section of wall to the right still has paper stuck to the wall. The section to the left has been stripped, and then scrubbed to remove paste residue.

The section in the middle is coming away to reveal a light colored clay-based paste still adhering to the wall. I will soak this, scrub it with a coarse sponge, and then wipe it with a softer sponge, to remove as much paste residue as possible.

Once the paste is washed off the wall and the wall has dried, I will apply a primer / sealer.

Note that this strip job was fairly easy and left no damage to the walls, due to a couple of important factors.

First, I think the original installer used a primer or sealer on the walls before hanging paper.

Second, the solid vinyl paper with its paper backing is generally easier than others to strip off. (However, I dislike this type of material, and find it poor quality, especially in rooms with humidity, such as bathrooms. The seams often show from the beginning, but also, as time goes by, especially in humid rooms, the seams often begin to curl, and cannot be glued back.)

On to the Third,,, the clay-based paste used by the original installer (and I’ve gotta wonder why he pasted the paper in the first place, since it was a pre-pasted paper – I follow the manufacturer’s instructions to run the paper through a water tray, which allows it to absorb moisture and expand as it’s supposed to, and also to become more malleable). But I also augment that by rolling on a thin layer of paste onto the wall. ).

Anyway, the clay-based pastes seem to rehydrate more readily than other pastes, and to separate from the paper more easily. They do leave a gooey, tan-colored mess on the wall, though. Which will need a bucket of hot water, a scrubby, and a lot of elbow grease to remove.