Roger,

Just need to add one additional comment, when working with Oxalic acid make sure you use the proper safety precautions. I recommend safety glass and rubber gloves when working with this product. It only take 1 splash in your eye with this acid and you will have serious problems.

SAFETY FIRST

John E. Freitag

President/Director

The Stone and Tile School

Office 407-567-7652

Cell 407-615-0134

jfreitag@thestoneandtileschool.com

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www.thestoneandtileschool.com

From: John Freitag [mailto:jfreitag@thestoneandtileschool.com]
Sent: Wednesday, May 13, 2009 10:11 AM
To: Restoration and Maintenance
Subject: RE: [sccpartners] Fw: Lobby Restoration

Roger,

I have reviewed the pictures and the floor may have been crystallized, usually anyone that knows anything about Thasos white would never bring steel wool or a crystallizer anywhere close to that floor.

I have maintain Thasos white floors in the past and never used any crystallizers and had a similar look. What happens to Thasos is that as the floor wears the dirt embeds itself into the stone and the grout gets dirty simply because it grout and it’s porous and with the cleaning process( usually dirty mop water the grout get dark and dirty) the appearance of the stone takes on a yellow look and it’s actually the dirt in the stone that give the stone this color.

The good news is that the floor is ground flat. That means that the honing process should expose new grout and clean grout.

I would attack the floor in the following manner.

1. The open area of Thasos white I would hone the floor starting a 220 and hone up to 800 to 1800 depending upon the shine you are going to achieve.

2. During my honing process I would grind using a neutral cleaner in my honing water, this will help clean the grout line and is always a good idea whenever you grind, the cleaner helps clean the stone and the grout and the cleaner suspends the slurry from attaching to the stone and grout and makes cleaning up the slurry easier.

3. Then after 800 or 1800 I would use the white granite powder and polish the floor to give it the extra kick using a tan or hog hair pad to polish with.

4. The green and black could be honed, however handle the green and the black as if it’s all granite if you even need to hone the granite, deal with each stone a separate issue.

5. If you notice in the picture of the boarder, you can see scratching in what appears to be a doorway or an area of traffic, you need to address this problem, if you don’t you not really addressing the entire job at hand, thus making the main floor look great and the edges and boarder look so so.

6. If you elect to hone this area treat everything like granite, QUESTION, IS THE GRANITE DAMAGED??? If it is not damaged then don’t touch the granite only work on the serpentine.

7. If you hone the serpentine attach you diamonds to a tan or hog hair pad using Velcro to hold your diamond to your pad. This process will allow your diamond to float over the lippage. This will give the edges of the stone a rolled appearance depending upon the lippage on the stone.

8. Keep in mind that the serpentine is a hard stone and the scratches you are seeing may not be as deep as they appear. You can probably start at a 220 , 400 800 then polish.

9. The oxalic acid will polish this stone great, BE CAREFUL if you have never polished using Oxalic acid straight, you only need to stay on the stone for a short period of time and work small areas.

10. I highly recommend using baking soda in your water to neutralize the oxalic acid after the polish is achieved. Use approximately 2 to 3 table spoons of baking soda per gallon of water. This is the best way to neutralize the oxalic acid.

The granite, if you need to hone and polish the granite let me know there is a complete process I can review with you. For as much as removing the crystallization from the granite there would be very little on the granite seeing that granite does not react to crystallizers the same way it does with marble. I would run the oxalic acid over the granite and this should remove the crystallization from the stone.

If you have not honed or ground a granite floor you may want to look at taking the Granite floor restoration class offered by The Stone and Tile School, this class deal with 16 different granites including absolute black, and yes we can hone and polish it back to its original color and shine.