Why Does Stain Wash Away?
Stain will simply wash away if you don’t open the surface pores of the
concrete first and allow the stain to penetrate.
I applied a dark brown acid stain to six-month-old concrete yesterday. When I came back today to neutralize the stain, it all washed off. What can I do to get the stain to take?
I get questions like this one almost every week, and not just from first-time stain applicators. When applying acid stain, understanding the basics are vital to achieving good results. (I’ll cover the four basic steps to successful staining in a future blog post).
In this case, the concrete surface had not been prepared properly prior to stain application. Onsite tests conducted to troubleshoot the problem showed that a mineral acid and detergent scrub were needed to “micro-etch” the surface (open the pores without changing the surface profile). This allows the stain to penetrate the concrete and react. Fixing the problem simply involved preparing the surface in this manner and then reapplying the stain. The stain was first applied to sample areas to assess the results. After 5 hours passed to allow the stain to penetrate and react, the samples looked great with very little residue on the surface.