Cob blasting exterior log wall

Sandblasting or Cob Blasting Off Deteriorated Finishes vs. Power Washing

Why is blasting better for logs than power washing? Read on to find out.

Sandblasting or cob blasting has a number of advantages over power washing. The process of removing a finish from the logs is – simply put – a matter of throwing something at the building at a certain velocity (or pressure) that is sufficient enough to take off the finish, while causing as little trauma as possible to the logs.


When dry, the surface of the finished logs is somewhat brittle. When the dry logs are hit with the sand or cob media, the brittle finish is quickly and efficiently removed leaving the logs relatively smooth. Blasting takes off old finishes and can lighten the color of the logs.


Power washing relies on water as the “media” to remove the finish instead of sand or cob. As water is applied to wood, it expands and more importantly – it softens the fibers of the wood. These soft fibers are then exposed to 1800 to 3000 psi of water. This process can cause the fibers to break length-wise and can result in what is referred to as the “fuzz effect”.

This basically looks like the log home or cabin has a grown ½” long hairs. Introducing more moisture to the wood is exactly the opposite of what log homes need because water is the enemy of a log building.

Another disadvantage of power washing is that water under high-pressure water can make its way into parts of the log building that have never seen moisture before. This can cause a number of additional problems including:

While it is almost impossible to keep a log home free from any leaking inside to some degree during either power washing or blasting, the problem with power washing is again, the use of water. Not only are you wetting the logs but also if water makes its way inside, it can stain or ruin interior finishes, floors and home furnishings.

water damaged wood after washing
In this example, water leaked inside the building and caused major staining of the interior logs.

The sandblasting or cob blasting material may come through the walls to some degree, but at least the dust is dry. Sometimes if there is a significant amount of dust coming into the home, we will drape the interior walls with plastic, allowing the dust to fall to the floor as it comes inside. This makes it easier to clean up with a vacuum or a broom.

For more information on sandblasting or cob blasting your log home, click here.

Edmunds & Company has a trained, professional crew for blasting off old stain or paint. Contact us to inquire about having your log home or cabin sand or cob blasted or call us at 715-373-5744.