Jun 14, 2008, 7:17 AM
Post #24 of 28
John, you can use a commercial product as Ed and Fran suggest, or you can do as so many folks do -- use whitewash as sealer/primer. I have used whitewash on my projects with good results.
Here is a quote from my website on the subject:
Whitewash blanqueo makes a good, inexpensive sealer and primer for preparing bricks, concrete and stucco for painting. Sometimes it is used without a top coat of paint. When used alone, whitewash has a limited useful life and must be re-done from time to time. How often depends on the climate -- the more humid, the shorter its useful life.
Whitewash is made by combining lime, water, salt and a binder. The binder commonly used in my part of Mexico is cactus paddles nopales. The lime used can be either builders' lime or quicklime. Quicklime has the advantage of making the nopales more efficient. The process begins by course chopping the nopales and adding them along with salt to a barrel of water. The lime is then added. (Your maestro will know the correct proportions.) Quicklime will react with the water releasing heat and a gas which should not be breathed. The heat will help to extrude the juice from the cactus. When the water has cooled, it is ready to be used. When first applied, the whitewash will appear thin and weak on the wall, but as it absorbs carbon dioxide from the air, it will turn white and cover the wall.