Bubbles On Wood Siding

A moisture problem would result in unfinished wood behind the bubble.

Bubbles on wood siding.

The new paint has sealed the moisture in the wood and has bubbled up in the places where the moisture is trying to escape. This has prompted some painters to theorize that the linseed oil had dried out in the original layers that sit on the wood and when the fresh top coat dries it pulls the old layer away from the substrate. Essentially the top layer of paint dries forming a barrier that prevents the solvents from escaping easily. Prevent new blisters by applying two coats of varnish or hand rubbed wood oil on the veneer and keeping anything hot or wet off the surface.

If scraping alone is enough the initial. Bubbles form as the result of a chemical reaction. Cover the repair with wax paper and a flat wood block then clamp the blister flat. Moisture blistering can be caused by the migration of water through an interior wall to the exterior thus pushing the paint off of the surface.

This problem is far more common when paint is applied to a hot surface. The bubbles were really subtle. Excess moisture on your painted walls whether from water droplets high humidity leaks or plumbing problems can cause water filled bubbles in the paint originating anywhere from the substrate. I can see how with the direction of the sun the color of the siding and the reflection from the low e glass the siding could bubble up a bit.

Use a scraper to carefully open the paint bubble. What causes bubbles one of the primary causes of bubbles in any kind of finish is moisture in the wood. Heat problems will result in a visible layer of paint behind the bubble. Heat blistering caused by painting in direct sunlight on a surface that is too warm.

Then remove the clamp and wax paper and lightly sand and refinish the surface. To see them you have to be on an angle. Let the glue cure overnight. In a large percentage of cases when we pop the bubbles we notice the bubbles open up right to the bare wood.

The best remedy is to scrape and repaint the siding during a warm dry period so the moisture can come out of the wood and prevent future bubbles from appearing. If your siding has been treated with linseed oil in the past prime and paint with oil based products. Not very easy to see right away. You don t say specifically whether just scraping off the bubbles reveals bare wood or whether the old paint stays intact until the painter sands it off.