An article by About.com
Patching and Sealing and All That Other Exciting Stuff
The act of painting the exterior of a house is just the tip of the iceberg in that massive project called exterior house-painting. Confused? You will be until the moment you commit yourself to a whole-house paint job–then you will know that the part with the paint cans and brushes and sprayers is relatively short compared to the preparation stage.
Even within this preparation stage, there is even another sub-stage, if you will, that makes a world of difference when done correctly or incorrectly: patching and sealing.
When you’re painting your house’s exterior, you’re like a remodeling doctor who now has the unique opportunity to get close to the house’s “skin,” identify past and potential diseases, and to cure them.
Outside of exterior painting, few homeowners even notice these siding and paint problems, much less do anything to solve them.
Why Is Patching and Sealing So Necessary?
It’s surprising how a tiny hole or crack in your siding can grow. Yet that tiny space lets weather into the wood (or whatever your siding material), past the protective layer of the paint. Once past that paint, it can do remarkable damage over time. Even the surrounding paint will start to be compromised by that emerging hole or crack. In wetter areas, rot can spread as fast as a cancer.
And that is fifty percent of the reason why we paint houses in the first place: protection. The other fifty percent? Style, of course.
Potential Problems and Fixes
Things you should look out for:
Problems: Small Nail and Screw Holes:
It’s easy to miss nail- and screw-holes because they are so small.
But they can present as much of a problem as do larger holes.
Fixes: You can buy filler in tubes made specifically to fill nail holes. Make certain that you do not buy a light-weight Spackle product for interior drywall. Some nail filler claims to be “no sanding required.” Other types require a light hand-sanding for a few seconds after the filler has dried.
I’m always dubious of the no-sanding types and instead prefer to start with a little lump and sand it down.
Problems: Hair-line cracks in the wood.
Fixes: Paint itself should be able to bridge small cracks.
Problems: Cracks large enough to fit a dime into sideways.:
Fixes: Larger cracks need to be filled by something other than paint. For long stretches, use painter’s caulk. For shorter spans, wood glue can help keep cracks in place and can double as a filler. Otherwise, use wood filler.
Problems: Part of paint peeled away, but not all of it.
Sometimes, you just need to scrape away a portion of paint. The problem is that this creates a depression in the wood that, after painting, can be visible from some angles.
Fixes: One solution is simply to prime, paint, and then forget it. If it’s not a highly visible area, chances are slim anyone will notice. But if you want a Grade “A” job, lay down a thin layer of wood filler in the peeled area. After it has dried, carefully sand down to the level of the surrounding paint.
Best solution is to replace rotted wood with new wood. But sometimes the area is small enough to patch rather than replace.
Fixes: Fill in with rotted wood stabilizer. It’s a special product that goes by that name.
Problems: Larger holes.
Fixes: Holes larger than a half-inch should be filled with something other than wood filler. Use a product like 3M All-Purpose Filler.
- Titebond III Wood Glue. I like this the best and I do recommend it over Elmer’s Wood Glue and most certainly over Gorilla Glue. I cannot say enough bad things about Gorilla Glue.
- 3M All-Purpose Filler.
- Caulk. Make sure you purchase paintable/stainable caulk. Otherwise, the paint will peel right off of it.
- Elmer’s Rotted Wood Stabilizer.
- Elmer’s ProBond Wood Filler (in the tube).