Asked on Sep 08, 2015

How do I remove black mastic stains from brick

by Jason
I recently bought a place with a large two story mirror covering a brick fireplace. I broke and removed the mirror and was left with large gobs of mastic that were used to affix the mirror directly to the brick. I used a putty knife, a lot of time, and Contractors' Solvent by De-Solv-It to remove all/most of the actual mastic. I am now left with the stained brick. I am assuming the solution will have to be chemical but any experience or advice to remove the stain would be more than appreciated.
Initial mirror to be removed
Mirror removed and large mastic spots remaining
After scraping for days
All mastic removed and only stain remaining.
  17 answers
  • Z Z on Sep 08, 2015
    I'm not a professional and have no experience with this type of thing on brick, but I thought I'd let you know that if you can't remove the stain, you might look into tinting or dyeing the who brick darker. I have no affiliation with this company, but it's what I could find so show you what it's like.
    • See 3 previous
    • Z Z on Sep 09, 2015
      @B. Enne ah, so more like a wash then.
  • Becky Becky on Sep 08, 2015
    have you tried sanding it, maybe?
  • Linda Linda on Sep 09, 2015
    There's a product called Lightning Strip that removes mastic, I haven't tried it, just saw it online. they might be able to advise you what to do.
  • Hope Williams Hope Williams on Sep 09, 2015
    You'll have to stain each brick that is stained already. You could do a design with it, you can put a layer of ready mix grout on it, paint, etc. just be sure to seal it with a Seal-Krete type first to prevent bleed through!
  • Janet Pizaro Janet Pizaro on Sep 09, 2015
    Maybe try a product called krud cutter usually sold in a paint store.
    • Stu Stu on Oct 19, 2020

      Krud Kutter doesn't work. I tried it and nothing

  • Judyms9 Judyms9 on Sep 09, 2015
    I'd be tempted to paint over this entire face of the brick down to the hearth level, as the corner appears very dark and a few shades lighter might be the solution. Brick is so porous that it's hard to imagine any product that will remove the mastic satisfactorily.
  • Pam Walker Pam Walker on Sep 09, 2015 THIS says it works on brick. Check it out. :)
  • Sharyn Diaz Sharyn Diaz on Sep 09, 2015
    Whatever you do the removal of the mirror was a major improvement the brick is fabulous.
  • LD LD on Sep 09, 2015
    Personally, if you want the brick to remain it's natural color, then find a brick mason to come look at the bricks and leave the cleaning to a pro. If you want to paint the brick then consult with a paint store for the necessary products needed to seal the brick and paint that is for masonry/concrete application. I would have the brick mason come and give you and estimate, for the brick work is very nice, and once you paint that is the way it will have to remain, for removing paint is very costly.
  • on Sep 09, 2015
    We agree with Linda. You may want to have a pro clean the brick if you wish to preserve the color and prevent crumbling. Another option is to cover it up. These ideas will show you how:
  • Marie Marie on Sep 09, 2015
    Look up DIY faux brick walls. This will give you inspiration on covering up the blotches yourself and save!! Nothing to lose, anything will be an improvement and if you don't like it then get help.
  • Mary Ker Mary Ker on Sep 09, 2015
    I wonder if Goof Off would work?
  • Christi Christi on Sep 09, 2015
    Might contact a mirror and glass company and seek their advice.
  • Janie Janie on Sep 09, 2015
    Look up PROSOCO online and call. They specialize in this kind of thing and work on commercial properties. They should be able to steer you in the right direction to DIY before going the expensive pro route.
  • Lisa Lisa on Jul 14, 2016
    What did you end up doing?
  • Stu Stu on Oct 19, 2020

    I just ordered product Gunther Remove. They make mastic so I assume their stuff to take it off works