Bubbles that don't go away

[Clark Kenyon]

I've had this problem a lot over the years. There is a certain kind of wallcovering, heavy paper, not vinyl coated or solid vinyl, but often with enough ink to make it necessary to use a premixed adhesive to get it to behave. (The instuctions that came with the material I'm currently installing recommend a clear, premixed adhesive.) The surface is new drywall sealed with PVA, which I go over again with Zinsser 1-2-3. Bubbles tend to form under the paper no matter how long I let it relax or how much I try to smooth them out. Trouble is, since the surface of the material is not impervious, it tends to dry fast, so the bubbles never completely flatten out (as they would were it solid vinyl, which dries more slowly). You can sort of feel the dried adhesive through the previous bubble. I wish I could control this problem, but I don't know if I should use the adhesive full strength (which is a bit of overkill since this is just paper and it makes the paper more difficult to handle) or dilute it (is diluting it causing the problem?). I was doing bathroom with this stuff last week and I tried various amounts of water in the adhesive, but I got the bubbles every time.

[ProWallGuy]

How are you applying the adhesive? Machine, or by hand?

[Clark Kenyon]

By hand, with a paint roller.

[Cliff Hayes]

Is it a certain brand of paper that does it every time?

[ProWallGuy]

I should have also asked what type of walls (plaster/drywall) and what prep/primer was used.

[Clark Kenyon]

The walls are new sheetrock, primed with PVA, I prime them again with Zinsser 1-2-3 and let them dry 24-36 hours. It happens with heavy paper with a lot of ink on it. Thinner stuff doesn't give me as much trouble. The adhesive is a heavy duty clear premixed.

[Clark Kenyon]

It seems that using the hd adhesive full stength gives the best results of avoiding bubbles, but it makes the material very difficult to handle. I think the problem is in the fact that this is just paper, but very heavy, something that in the past would have called for a powdered vinyl adhesive or (earlier) wheat paste. (The poor tack of such adhesives would have created different problems.) The substrate absorbs the moisture in the paste, which creates the bubbles, which would normally disappear as the material tightens to the wall. But the adhesive trapped under the bubble dries quickly, leaving a sort of lump shaped like the bubble. Maybe it would help to dilute the adhesive, apply it to the wallpaper, let it expand, then reapply. I hate to have to keep experimenting with this. I was just trying to find out if other people had encountered the same type of problem. And could offer a quick, foolproof solution.

[Chris Murphy]

I'm very familiar with problems with 'hard inks'- non-permeable inks that don't expand. But not with the bubbling you mention; more trouble with edge curl, or a mix of inks where the substate expands unevenly (hard inks making the pattern non-expanding, while the rest grows).
What are you calling PVA?
With the above scenario, I'll use a full-strength clay, like Dynamite 111, with sized seams and/or blankstock, rolled on as thin as possible. I find these problems unrelated to paper thickness; indeed, these papers are a synthetic mix + pulp. They didn't exist before the mid '70's as wallpaper, pulp paper was exclusively used before then. Not that either substrate would make much of a difference with these inks. I think the inks were reformulated in response to environmental regs, but its hard getting a straight answer from paper makers & printers.
Specifically, what HD clear are you using? Something like 880 would not dry as fast as 234, for example. Have you tried blankstock (absorbent blank pulp paper)?
Then there was the problem that Barry Blanchard & Mike Stachnik discussed with a specific B&F that Barry solved by wetting and bagging overnight. But the hard inks don't respond to this.

[Cliff Hayes]

I think the problem is in the fact that this is just paper, but very heavy, something that in the past would have called for a powdered vinyl adhesive or (earlier) wheat paste.

If it's truly a breathable paper, try Ecofix P7. It's a potato-starch adhesive that works really well with brit-pulps (Osborn+Little, Nina Campbell, etc.). It comes in an 8-bag case, and one bag will make enough paste to hang about a dozen rolls. Very cool paste. Comes from Sweden, and I buy it through my local Duron paint store. You can buy it directly from Roos International, the distributor in the USA. www.roosinternational.com . Their P7 web page seems to be out of order, but you can call them at 1-800-888-2776, and ask for Deborah Roos. They are hip to the NGPP, so mention the Guild and tell them you'd like to try a couple of bags.

[Clark Kenyon]

PVA is polyvinyl acetate, a common water based primer used on sheetrock in new construction around here. Not something you'd want to just paper over without another coating of acrylic wallcovering primer.
The adhesive I've been using is Dynamite 234. As I said, my best results came with using the adhesive undiluted, which increased the difficulty of handling the paper once pasted.

[ProWallGuy]

I agree, I won't hang directly over pva myself. And I too use 234 almost exclusively, rarely thinned. But in this instance, you might want to try the P7, it might tame the beast. I have used it once before, and really liked the tack it provided for being what I would call a light-weight paste.

[Dano]

Use adhesive delayer such as ?