Slippery Rock Gazette

Bob Murrell 

M3 Technologies

Photos by Bob Murrell

A restoration contractor was working on a French limestone floor strip and polish (one of two halls on either side of a dining room and front grand hall). Both halls had windows on one side and the dining room on the other (in between the two parallel halls). The sun came up in the morning and shone directly into the south hall on the stone floor. Now, you might think that the sunlight coming in was helpful when evaluating the floor. However, this direct sunlight actually made it very hard to see certain aspects of the progress on the floor. Areas where the applied topical coating still remained (like low spots) were actually hard to see.

So, even after the stripping with natural pads and commercial stripper, then polishing with Majestic 5X Gold was completed, these low areas were missed. Normally, most restoration professionals are good at seeing and rectifying missed or problem spots, but due to the existing lighting conditions, they were accidentally overlooked. We’re all only human... 

To set the stage, the south hall was stripped early one morning and the north hall was stripped later that afternoon. The south hall looked like it was thoroughly stripped and no more attention was paid to it that day. So assuming (and we all know what assume stands for!) that the south hall was properly stripped and was ready to polish, the remainder of the day was spent stripping the north hall and then polishing it.

There were stubborn low spots and corners in both halls, but on the north side they were easier to see as the lighting was more consistent and much less bright, especially in the first part of the day. Naturally, as luck would have it, they polished the south hall the following morning and all appeared good. Therefore they continued polishing around to the front entrance and grand foyer.

As the front entrance foyer and north halls were finished up, all appearances were that the floor was looking very nice. Thinking that the floor was basically finished, equipment was cleaned and wrapped up as well as tooling and products. This was probably around 5:30 p.m. , and of course, the homeowner was the one who came in and noticed that there were still low spots of product — and something else even more disturbing. There were etch marks where someone had dripped something acidic down the middle of the south hall, and some corners still showed product, and a lack of even polish. How could these have been missed? These etches and unfinished corners were very noticeable in the later part of the day, when the sun was no longer shinning directly on the south hall floor. However, later in the day when the direct light was gone, say after 5 p.m., every flaw in the floor was like it was lit up with a black light.

Bottom line is, they had to go back and address each etch, low spot, and corner, one at a time. When possible, and to help reduce surrounding area re-contamination, diamond hand pads were used for honing. A hand tool would’ve slung stuff everywhere, and the Tape & Drape had already been removed. To re-tape everything would take many much needed hours, which could be much better spent towards the resolution. Some of the problem areas were low and still contained some of the sealer too, and were therefore chemically stripped first, before honing and polishing took place. 

Above, left: Once the lighting had changed, the contractors were able to clearly see areas that had been missed, like the floor by this rounded corner.   Above, right: This is the south hall after the coating was stripped. Looks pretty good, doesn’t it? However, there are etches and low spots (still with some coating) down the middle of the hall which are not evident under these lighting conditions.

Another, similar project involved an antiqued travertine, which had had a Mop & Glow product applied. The same lighting issues were present. This floor was more forgiving, and at least the coating had somewhat protected the floor from any severe etching, and was fairly easily removed. 

It did, however, have a very plastic-like and unnatural appearance, and some of the specific issues with the floor became more evident as the skies clouded up before a rain. The pattern of many windows and bright sunlight seems to disguise some of these issues. So once again, as the direct sunlight faded, it was easier to see the issues with the floor. 

The floor was stripped using a commercial stripper and a fine grit (about 500g) abrasive, high-low brush. Once stripped, both the stone and the grout were cleaned with Majestic Deep Cleaner Degreaser. This worked very well for the unfilled antiqued travertine in this installation. A hand-held wire grout brush was also used for stubborn areas of the grout. As a side note, I most always recommend using a natural pad for stripping on marble and similar stones, as a black pad, which can be fairly aggressive, could further degrade the surface and require some deeper honing to reverse. If the floor must be honed anyway, then a black pad would be faster at coatings removal. This should all be determined by a test area prior to general application.

Once the coating had been effectively removed, the floor was then high-honed with a 12,000 grit diamond impregnated pad. This dip did a fantastic job of restoring a nice luster to the antiqued travertine. The level of shine was actually close to that of the previous coating, which was the effect the customer wanted. 

In any case, the contractor and homeowner agreed that they would return to the Mop & Glow type product as this would give better protection from acidic spills than just an impregnator by itself. It actually looked pretty good. This is one of the few times that I would even consider a topical product, but because this was a kitchen and the restorative procedure worked very well, the contractor saw the value in it. 

Above, left: This area of antiqued travertine has been stripped of the coating and cleaned.   Above, right: The same area of cleaned travertine after 12,000cgrit diamond impregnated pad was applied.

To sum up, if you think that more sunlight is better, this may not always be the case. Take care that you can see the surface with other than direct sunlight, when many of the flaws may be more noticeable.

As always, I recommend submitting a test area to confirm both the results and the procedure prior to starting a stone or hard surface restoration or maintenance project. Also the best way to help ensure success is by partnering with a good distributor, like BBI, that knows the business. They can help with technical support, product purchase decisions, logistics, and other pertinent project information.

Enjoy being with your family and living life to the fullest!

Bob Murrell has worked in the natural stone industry for over 40 years and is well known for his expertise in natural stone, tile and decorative concrete restoration and maintenance. He helped develop some of the main products and processes which revolutionized the industry, and is currently the Director of Operations for M3 Technologies.