I have recently used different chemicals to restore, refinish and treat various types of wall and millwork surfaces. E.g. I have stripped old paint using Peel Away 1 from plaster and antique millwork, which I believe is basic and needs to be neutralized with acid (vinegar or similar). I also cleaned mortar and dust residues from exposed brick using hydrochloric acid, which I neutralized with a baking soda solution (basic). In yet another example, I plastered some brick walls with a homemade plaster mix (hydraulic lime + sand), which also is basic.

After completing all of these surface treatments, should I always aim to achieve a pH of 7 by neutralizing with a solution of the opposite pH? Or are there other factors to be taken into consideration?


If you are cleaning something that can be washed, you can neutralize the pH with water. After using HCl on bricks, I would just hose them off. The acid will become very dilute quickly. pH just measures the concentration of hydrogen ions in a solution, so if you add a bunch of water (neutral pH) the pH will approach neutral.

I also don't think you need to worry about the pH of solids such as dried plaster.

  • i couldn't hose it off, it was indoor. so i sponged it with baking sode in water
    – amphibient
    Feb 21 '13 at 20:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.