Replies

1. 
   Henley | Aug 29, 2008 02:44am | #1

   Muriatic should have been your first try. It will work-slowly.
   Several go overs if it's very stubborn.
   And watch your joints! they will be degrading as you scrub.

   Mix it fairly weak and scrub like nobody business.

1. 
   gfallon | Aug 29, 2008 04:11am | #2

   thanks

1. 
   EricPaulson | Aug 29, 2008 04:36am | #3

   Muriatic acid IS sulfuric acid and should at least help you achieve your goal.

   You might try laying moist towels over the area for a day or so before attacking it with more acid on the next go round. Look into getting a brass or bronze wire bistle brush or a stiff plastic brush. Let the acid sit and do it's work.

   Try the grout manufacturers hotline.

   And be careful with the acid. Respirator, windows open safety glasses.[email protected]

    

    

    

    

1. 
   brucet9 | Aug 29, 2008 06:10am | #4

   "Muriatic acid IS sulfuric acid ..."Muriatic is hydrochloric acid (HCl) not sulfuric (H2SO4).BruceT

1. 
   EricPaulson | Aug 29, 2008 01:10pm | #6

   Thanks. I sorta new that was incorrect.

   Care to speak to their properties and usefulness as it pertains to the thread? I'd be interested to learn more...............[email protected]

    

    

    

    

2. 
   brucet9 | Aug 30, 2008 05:11am | #9

   "Care to speak to their properties and usefulness as it pertains to the thread?"Sulfuric is a strong oxidizing acid, very hazardous and not as effective in reacting with cement products as muriatic is. Even in dilute form it does a lot of damage in the Eastern US in the form of acid rain. It is also the primary reagent in lead/acid car batteries.See 109037.6 for my detailed suggestions to the OP.BruceT

   Edited 8/29/2008 10:14 pm by brucet9

3. 
   EricPaulson | Aug 30, 2008 02:54pm | #10

   Thanks for the info.

    [email protected]

    

    

    

    

4. 
   Dreamcatcher | Aug 30, 2008 04:51pm | #11

   Bruce,That's pretty interesting. Would that have anything to do with the reason that hydrogen peroxide and oxide cleaners works so well at removing cement and mortar? I got a free CI tub from a job and needed to clean up the rim. I found that the best things to clean the old grout&mortar off was "Fantastic Oxypower" cleaner (which is basically just hydrogen peroxide)and for thicker, more difficult areas, I used The Works (which of course is hydrochloric acid). I cleaned it on my brand new garage floor, now I have a perfect circle eaten away from where the drain was sitting and the works pooled. Mighty powerful stuff.gk

5. 
   Accelar | Aug 31, 2008 12:37am | #12

   We cleaned the skunk smell off our our dog (AGAIN!) over a tiled porch with a mix of peroxide, baking soda, and lemon dish soap. (incredibly effective by the way - all three times !)The next day I removed the tiles that hadn't already shifted by applying next-to-no force at all. Thank goodness those tiles were going anyway, or the dog would have been up for adoption.Wish I had thought of that recently when dealing with exactly the same problem you have with slate tiles. The only other thing I would add to earlier posts is that I found a cheap plastic handled metal bristle BBQ brush, with a scraper on one end was great for the job. I applied the muriatic acid (diluted a bit) from an old plant sprayer bottle and scrubbed with a series of green 3M scrubber sponges. Usually sprayed, let suit while working another area for 2 or 3 minutes and then came back to it in order to let it work for a few minutes. Used the BBQ brush for the tighter crevices, and - very carefully - the scraper on the biggest problems. Acid can be left on the wall in tricky spots by spraying till visibly wet, then applying a sheet of saran / food wrap that will stay up with the static pressure. Wipe the seams with water as soon as possible, and don't leave the saran covering them or risk having to redo the whole job. I usually had success after letting it sit on a tough patch for about an hour. Some took several applications, removing a bit each time.Most of the remaining problems disappeared under a coat of gloss sealer.Good luck !
   Gavin Pitchford

   "Sail fast - live slow" (build even slower)

6. 
   brucet9 | Aug 31, 2008 08:05pm | #15

   Hydrogen peroxide (H2O2) is a very strong oxidizing agent, stronger than chlorine, so it is an effective bleaching agent. As far as I know it should have no effect on cement products save to clean stains off them. Some cleaning formulas use acetic acid and H2O2 where the fizzing action of the H2O2 serves to agitate the solution and promote contact of the acid with the surface.BruceT

2. 
   gfallon | Aug 29, 2008 09:04pm | #7

   unfortunately the tile is on the wall but I do appreciate your thoughts
   g

3. 
   BillHartmann | Aug 31, 2008 01:23am | #13

   Acutally he said SULFAMIC acid.http://www.aquamix.com/products/pg_detail.asp?pdid=328&pgid=9833And it is one the cleaners specifically sold for removing grout haze..
   .
   A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

1. 
   EricPaulson | Aug 31, 2008 03:44am | #14

   doh!

   Just assumed it was a spelling error.

   Thanks for the insight![email protected]

    

    

    

    

2. 
   brucet9 | Aug 29, 2008 06:21am | #5

   Muriatic acid is the strongest chemical for cleaning up grout and mortar stains. It is powerful stuff and must be handled with care and only with safety precautions like wearing heavy rubber gloves, goggles, long sleeves and having plenty of ventilation in the room.

   Phosphoric acid is also pretty effective, albeit slower than muriatic, for minor staining and is much safer to handle.

   Be sure to rinse all TSP residue away before using acid, especially muriatic, because dangerous vapors can result from TSP reaction with acid - chlorine gas, in the case of muriatic acid.

   BruceT
1. 
   gfallon | Aug 29, 2008 09:06pm | #8

   The possiblity of chlorine gas is a danger that is not well appreciated!Thanks for the tip
   g