This article is about how to patch scars left by removal of peeling exterior paint on stucco. Please note that it is not about removal and replacement of failing stucco. If you are replacing larger areas of missing stucco, you will want to use a dry cement product, mixed with water. In this article, we discuss cosmetic repairs, not how to mix and apply Portland cement and sand. For that type of advice, try Kirk Giordano’s videos.
Over the years, we have encountered many old San Francisco homes with cracks and loose and peeling paint on the stucco. Often the old paint comes off in irregular patches of varying depth, leaving an uneven quilt-work of scars. The cracks, when cleaned out and patched, still show through. As professional house painters, our aim is to produce the most durable paint job possible, while making it aesthetically pleasing. So how to blend your patching to get the smoothest possible results without re-finishing the entire surface?
Clean And Prepare The Surface
First, clean the stucco and then scrape off any peeling paint (a “5 in 1” or flat scraper works great for getting under peeling paint). Next, evaluate the areas to be patched for “chalking”. You can do this by rubbing your hand on the surface. If it comes away with a white, chalky film on it, then you will need to apply a binding primer. There are a number of masonry primers that will bind chalk, or you can use a binding primer such as “Zinsser Peel Stop” or “rainguardpro”. We recommend the former, as it is readily available in most hardware and paint stores.
How To Patch Scars Left By Peeling Stucco Paint
Again, we are discussing the use of acrylic-based, ready-mixed products for cosmetic repairs, not replacement of large areas of missing stucco. Once your surface is ready for patching, evaluate the type of texture you have and how deep the repairs need to be. For deeper patching of cracks, holes, chips in the stucco we recommend using a “pre-mixed stucco patch”. There are several on the market, made by Sakrete, Dap, Zinsser and Bondex. These products are thick-bodied and sag-resistant, so they stay in place when applied to a deeper repair.
If your goal is to smooth out peeling paint edges or cover hairline cracks, try using an elastomeric stucco patch. These can be either smooth or textured, and can be of a thicker (knife grade) or thinner (brush grade) consistency. Often times, we will use a combination of products, starting a deeper fill with the pre-mixed, then applying an elastomeric patching compound over that.
The Key To Blending Stucco Patches
Before starting, you will need a couple of flexible drywall knives in the 4″ to 10″ range, a bucket of water, a spray-bottle and a 3″ to 4″ soft bristle brush. One could also use a “sponge float” but we find the brush to be easier. First, apply your patching compound with a flexible joint knife, filling in cracks, holes and rough paint edges. A 6″ blade works well. Now comes the key to blending: Before the compound can set up, wet it with a spray-bottle and then lightly fan and blend your patch with a soft, wet brush. You can keep the brush in a pail of water, and experiment with the amount of water needed to blend your patching compound and also melt your brush-marks. If you are applying more than one coat, allow each coat to dry thoroughly before applying the next one. With some care and artistry, you can obtain a fairly smooth, uniform result! In the following photos, we used sure-stik 100, a textured, knife-grade product, to smooth out paint scars in a rough surface.
Francisco applies the patching compound over a scarred surface, then wets it and blends in the edges using a soft, wet brush.
