Posts Tagged ‘ecofix cellulose based paste’

Bradbury & Bradbury Job – Loose Seams

January 20, 2012

For more on this story, read previous posts.

After working through a million types of paste (a slight exaggeration), and finally finding one that worked well with the paper and did not leave staining or “dark seams,” I was happy to have the job finished, and the homeowners reasonably satisfied.

But then a few weeks later came the call: “Julie, the seams are coming loose.”

When a job is well done, wallpaper stays on the wall, usually for years and years. One of the main factors that causes paper to come loose is humidity. (And I’m sure I’ll blog on that biggie some time down the road.) But this B&B was hung in a dining room, not a bathroom, so humidity was not an issue.
I was curious to see what had happened.

When I got to the house, I saw that the paper was, indeed, coming off the wall, with large areas of the seams coming loose, even up to 3″-5″ in spots.

Looking at the back of the paper, I didn’t see paste, which is what you would see if the paste had not held tight. Instead, the paper had a thick feel, and had a thin layer of the white primer adhering to it.

I’ve seen this once before – the primer had delaminated. Meaning, that the primer had come apart in layers, leaving one thin layer on the wall, and one thin layer on the paper, held by the paste.

I have only had this happen one time before, when friends talked me into using a water-based acrylic primer. So I was very surprised to see this happen with my standard oil-based KILZ.

Since the problem was only on the bottom section of the room, which was hung with the clay paste (the upper sections, which were hung with cellulose paste were fine), my surmization is that the failure was caused by an incompatibility between the primer and the clay paste.  Indeed, I have since learned that, due to the “green movement,” polymers in oil-based primers have changed, and pastes no longer stick to them, or at least not as well.  This experience seems to bear that out, as least with respect to clay-based paste.

But to deepen the mystery, the only walls with loose seams were the east and west walls. The north and south walls, and two narrow east and west walls, were perfectly adhered.

Weird!

Weird or not, mysterious or nor, the homeowners needed to have a proper looking room. So, after carefully measuring and plotting to be sure we had enough left-over paper, all the loose paper on the worst wall was torn off. There was just enough paper left to redo that wall, this time using cellulose-based Ecofix paste purchased from B&B, being careful to place the seams so they did not overlap where the old seams had been (to minimize stress on the wall, and minimize the chances of the seams pulling up – for a whole different reason, which just might be the topic of a future blog!) That took care of the west wall.

The east wall didn’t have as bad of loose seams (pardon the grammar), and we didn’t have any more paper anyway, so I worked the paste into the loose areas to readhere the paper to the wall.

This sounds like a quick fix, but is in itself tricky, because the moisture from the paste, as well as from my rags wiping the surface clean, can cause sections of the paper to swell and lift away from the wall, causing even more problems. The trick is to use enough paste to get the paper to stick, but not enough to allow moisture to wick to other areas of the paper.

This wall also had some shrinkage of the paper, which left very narrow strips of white showing at the seams. Once the paper was repasted, it stretched enough to mostly cover this. To be sure no white showed, though, I painted the wall just beneath each seam, a color that nearly matched the paper.

The replaced west wall looked good, the repaired east wall looked good enough (but I am not confident that the inner sections of the strips, which are still adhered with clay paste, will not eventually start to come away from the wall).

With the furniture placed back in the room, and people looking at the food on the dining room table instead of the walls, everything will be fine.

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