Treating Water Stains

This window had leak issues ( rain , sprinklers ) some years back, which have been solved by replacing the window, and doing other repairs.  In the photo, I’ve applied my light blue wallpaper primer to the top half of the wall but not yet the bottom portion, so that’s why the color difference

Even though the leak has been stopped, vestiges of it are still appearing.  Water that entered the wall left vertical streaks on the drywall .  All these years later, after the paint and texture have been removed , the stains remain.

Water stains , along with some others, such as blood , rust , ink , marker , grease , oil, cosmetics , and the like, will bleed through joint compound , primer , paint , and wallpaper , creating new stains on the surface .  It may take a couple of months , but they will make an appearance . In this photo, I’ve already applied my blue primer. It only took a half an hour for these stains to work their way through.

This is the top right corner of the window , where the bracket for the mini-blinds is attached to the wall.  Note the stains on the underside of the window . 

To prevent these stains from working their way through the new coating / paint / wallpaper , it’s imperative to thoroughly cover them with a stain blocker .  And – trust me – water-based products won’t work, despite what the label claims.  You need an oil-based product like this KILZ Original , or a shellac-based like BIN by Zinsser .  Both are prone to splatter , so be sure to cover your floor and baseboards with dropcloths .  KILZ has strong fumes and can make you high , so ventilate or wear a respirator mask .  It’s a hassle cleaning the liquid out of the brush , so I use a cheap-ish disposable “ chip brush ” from Home Depot or Sherwin-Williams .  The products usually dry pretty quickly.
Note that wallpaper paste won’t stick to most oil-based primers , and shellac is too glossy for good adhesion , so I’m going to go over the stain blocker with my usual Roman Pro 977 Ultra Prime wallpaper primer , which sticks to just about everything , and creates a good, matt finish surface for the wallpaper to cling to.  

Fixing Weird Things That Happen To Wallpaper

The top photo shows a stain on the wallpaper that is probably related to a rain or hurricane event a few years ago.

Water stains (and also other substances, like rust, blood, ink, oil, tobacco, tar, cosmetics, and more) will bleed through wallpaper. So, before patching the area, it is imperative to use a stain blocker to seal the problem. My favorite is KILZ Original oil-based.

KILZ will seal off the stain all right. But wallpaper won’t stick to it. So, in the third photo, you see where I have primed over the KILZ with a wallpaper primer (tinted light blue, for visibility). It’s not necessary to prime the entire wall area to be patched, because this type of wallpaper will stick to itself with just plain old adhesive.

The striped pattern made for an easy repair. I took a straightedge and sharp razor blade and trimmed along the striped design, creating a long skinny patch. See fourth photo. You can also see the strip pasted and booked (folded pasted-side-to-pasted-side).

Once that sat and relaxed for a few minutes, I took it to the wall and appliquéd it over the damaged area, going the full height.

There was a very slight color difference between the paper that had been on the wall for 20 years and the paper that had been in a dark closet. Had I placed the white area of the patch next to the white area on the existing paper on the wall, the color difference would have been noticeable. But trimming along the blue stripe gave the eye a logical stopping point, and so the color difference is not detectable.

In the finished photo, you would never guess there had been anything amiss with this wall.

I used this same technique to patch over the bug-bite holes in yesterday’s post.

And another good reminder that it’s always best to order a little extra wallpaper, in case of the need for repairs later. Store the paper in a climate-controlled space … not the garage or attic.

The wallpaper is by Schumacher, and appeared to be an old-school pulp paper material.