Slippery Rock Gazette

Bob Murrell 

M3 Technologies

Photos by Bob Murrell

This month I’m presenting a unique story about a local fabricator who contacted Knoxville Marble Polish regarding some damaged marble slabs that had been stored outside. Rain (acidic) had left run lines (light etching) down the slabs, along with general environmental contamination from birds and whatnot. Stone Creek Surfaces had previously paid another local company, who had the means, about a $1,000 to re-polish slabs – plus the risk and inconvenience of loading them up and shipping them to be processed, and then returned. 

Marble and other slabs stored outside can develop environmental damage like drip or run lines from acid rain, bird droppings, etc.

So Trenton, who is the fab shop foreman, called and asked if it was possible that these could be re-polished more efficiently in-house at their location? Of course, the answer was a resounding yes! For a restoration contractor, re-polishing slabs is easy stuff as there are no grout lines, lippage, nothing to tape off, no stairs, plenty of easily available water, and a rare perfect environment for our type of work. 

There was, however, one big caveat: the slabs had to be polished on the CNC gantry saw bed as this was the easiest place to load and unload the slabs efficiently. Of course, the saw bed was about 3 feet off the floor! Trenton had looked at several hand-operated slab polishing machines, but these were very expensive (at least for the serious models), and it would still be hard to reach across a full slab, typically a 4 foot to 5 foot wide by 10 feet or more long piece. Also, with a 17-inch floor machine, the polishing process would go much, much faster than with a hand-held machine.

Now for me, this was not a problem. I have been running floor machines of all types for well over 40 years now. Once you have the balance of the machine down pat, it is basically effortless.

There are exceptions of course, like polishing granite with 175+ pounds of weight on the machine, or severe lippage removal, for sure. But other than that, I have learned to become one with the machine. The machine works for me, not the other way around.

For those who don’t have the many years of floor machine experience under their belt, it can be quite a scary task, at least in the beginning. And this is running the machine on a flooring surface, not elevated 3 feet in the air on a CNC saw turntable.

As you can imagine, this is a daunting operation with the possibility of dire consequences. If the machine were to go over the edge, it might very well drag the operator with it — Not to mention that this would certainly be detrimental to the machine! 

The idea is to load the slab on the CNC gantry saw turntable and repolish the slab using a floor machine. With many years of experience, polishing on the bed of a saw is not too difficult for me, but is still dangerous. I recommended a bumper system be installed to help with fall safety issues.

Using the floor machine 3 feet off the ground was the primary concern, for safety reason. This operation can be dangerous. You can see the accumulated grime in this photo.

Now, the fab shop technicians were all watching me re-polish their Calcutta Viola and Calcutta Nathalia slabs with ease. And rightfully so, they wanted to get their own machine to be able to accomplish this going forward. Most fabrication shops do not have ample storage to be able to keep their slabs inside or even under cover, so this environmental staining, on marble especially, is a very common problem.

So Trenton and I discussed them getting their own machine. Of course, I’m in the machine selling business, so I worked up a quote for them and included all of the accessories I thought they might need, at least initially. I agreed to help them get started so they could work on doing this procedure on their own.    

The machine arrived and I came out to help them get started. We opened everything up and I went over the operation of the machine, for polishing only. I showed them where to adjust the handle, which is typically just below the belt. I explained that you lift up on the handle to guide the machine to the right and push down to guide the machine to the left, and that this is most safely done in very small increments.

I had them practice on the shop concrete floor with an old natural pad. They were able to control the machine, but discovered quickly that it will take some time to get the level of confidence and control necessary to operate the machine on the saw table. I had Trenton try it, but it is a pretty scary situation when you’re new to floor machine operation, and three feet off the ground, to boot! So, they admitted they’d need to continue to practice on the floor for a while longer.

I also discussed the possibility of them constructing some type of bumper rail system around the saw turntable bed, say with 2 x 6s or something similar. I believe this would definitely help and be much safer for the shop. 

I think with a bumper edge system installed on the turntable, this could be a very effective method for the re-polishing of marble and other materials as well as taking a polished slab to a honed surface. In fact, this could be a game-changer for honing slabs. Here in the US, honed materials are not as easy to come by, and with this operation in place it could save both time and money for a shop.    

We’ll see how this plays out at Stone Creek Surfaces and I’ll report back at a future date with the progress. Of course, Trenton knows that I am not too far away and will help if they need me. I want this to be a success. We just need to ensure the safety of the operator as well as the machine. So for now, this is still in the experimental phase, but with some safety features installed, it looks promising. The main advantage of this set-up is speed. I can repolish a slab in 30 minutes or so quite easily, so this is definitely the goal.   

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.