Slippery Rock Gazette

Bob Murrell 

M3 Technologies

Photos by Bob Murrell

Happy New Year! I love being associated with the restoration of historical buildings. Bringing an old marble (in this particular case) installation back to its original, as-installed beauty, gives me great satisfaction. One of the oldest churches in Knoxville is First Baptist Church, Knoxville. It was established in 1843-1845. The current historic church building was built in 1923 and was the third and final building of the church assembly. The architect was Dougherty & Gardner and the church was built in the Neoclassical or Classical Revival design with an octagonal sanctuary. It was placed on the National Register of Historic Places in 2010.

The Neo-Classical First Baptist Church, Knoxville building is 100 years old this year.

So, 100 years later and with countless coats of everything from paste wax to acrylic, it is now time to restore all of the – and you guessed it – Pink Tennessee Marble. There are a couple varieties of the Pink Tennessee and some other stones too, such as Belgian Black Marble (which is actually a limestone). I suspect that these marbles were in fact quarried or imported locally at one of the quarries that eventually were all grouped under the one company, The Candoro Marble Company. These Tennessee pink marbles were quarried, fabricated, shipped, and installed all across the country in government buildings, museums, hospitals, churches, and was even very popular with residential windowsills for many, many years. The Candoro Marble Company also became a very large importer of foreign marbles (like the Black Belgian Marble), and granites from all over the world.

The biggest issue with the marble floors, stairs, bases and other surfaces was that over the last 100 years, they had been coated with many applications of both paste wax and acrylic. I don’t know if these maintenance chemicals had ever been stripped or removed previously, as the coatings were very thick. It was so thick that a fresh black pad might last a couple of hundred square feet (at best) before it was blinded on that side of the pad. Even the stringers of Belgian Black were coated in some sort of acrylic, like, old Mop & Glo, Super Shine-All, or similar. All of the marble surfaces were a streaked, scuffed, dingy, yellowed plastic-looking mess. Initially, there was no clue as to the actual condition of the marble surfaces beneath all those many layers of coatings. 

The church agreed that the original intent of the marble floors and stairs was to be honed. After the coatings had been sufficiently removed and the stone could be evaluated, there was no evidence of any originally polished marble on the horizontal surfaces (floors or stairs). The only polished surfaces were the Belgian Black stair stringers and baseboards. 

Above, Leftt: Belgian Black stringers on the staircases had been coated with an acrylic. Above, Right: The coating was laboriously removed and Tenax Ager applied.   Below, Left: The stripping process removed decades of coatings. Below, Right: Black floor pads blinded by the coatings removal process.

Slapwax on the Belgian Black baseboards.

A restoration plan and procedure was eventually decided. Several heavy high-alkaline strippers were to be used: Majestic Ultra Strip and AcryliStrip. One worked better on the floor finish and the other worked better on the acrylics. This was a very tedious process. Note that it is preferable to use warm water with the strippers, to help increase efficacy. 

These layers upon layers of coatings would melt and turn into a viscous, snotty-looking membrane. Using the machine, with one horseshoe weight (about 125 pounds total) and the black pad at the right moment, was essential. If you started too soon, the stripper wouldn’t have adequate contact time and may not have loosened or melted the layer being attacked yet. If you waited too long, the membrane will simply settle back down and re-adhere to the surface again. It is best to get into an efficient rhythm when removing many years of heavy layers of multiple product coatings. It goes much easier when you are prepared and can make the necessary adjustments when needed. 

It took several stripping applications to remove the coatings. The borders or edges required razor blades, as did the stairs (this was the most back-breaking part of the project). Basically, all of the detail 90° joints required both stripper and razor blades to successfully remove all of the plasticized coatings. Razor blades were also used on the stringers and baseboards, which had “slapwax” all over them. Slapwax is the result of slapping the mop or applicator against the baseboards when applying the coating to the floors. It is paramount to frequently change to a fresh, sharp razor blade to avoid scratching the marble. Pro tip: Buy razor blades in large quantity packs of at least 100. Doing the coatings removal right required a lot of detail hand work.

Disposal of your wastewater (stripper and coatings) is also an issue that must be dealt with. You can strain the wastewater with some sort of cheesecloth or similar material to help remove the solids (coatings) before disposal down the drains. Remember, this stuff was like a thick film the consistency of mucous. Check with the property owners to see where the best location for disposal is. In some cases, you may be required to haul any and all effluent away from the work site for disposal. 

Once the coatings were completely removed, a PLP 400 grit pad was used to basically exfoliate the marble surface. This helped to remove any residual coating, dirt, and light scratching. The floors looked pretty good at this point. However, after many years of seeing shine from the floor coatings, you know what the property owners said – they would like to see more shine, of course. So a 3,000 grit PLP was then used to create a nice patina (shine). This looked really nice and the owners were very happy with this look.

Left: Restoring the stairs involved some serious (and tedious) handwork. Right: Tennessee Pink Marble stairs after coating removal. Tenax Ager was applied to the Dark Pink Tennessee marble to restore the deep, rich contrast.

Tenax Ager was used on the darker pink marble borders, baseboards, and stringers. The field of lighter pink was impregnated with AkemI Color Intensifier to help enhance color and give protection. 

The project turned out very nice and the church was very pleased with the results. Maintenance going forward will be much easier and the surfaces should look great for many years to come. Basically, dust mopping and damp mopping with either Majestic No-Rinse Neutral Cleaner or Majestic Stone Soap will be all that is required. Maybe every few years the floors might need freshening up with a 12,000 grit PLP pad and that’s it. 

The overall finished look was very nice, and the Church leaders were extremely pleased with the results

It is most always easier, more cost-effective, and with better appearance, to maintain stone naturally than it is to maintain a coating.    

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

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.

Send your comments and questions to Bob at attn:publisher@slipperyrockgazette.net .