Found on craigslist for $50 almost a couple years ago, I knew this marble slab which had a former life as a table top would make a beautiful bathroom vanity top …. and then it sat in our basement for nearly two years until just recently.
Countless hours spent googling “how to cut marble slabs” and perusing DIY chat rooms didn’t reveal much about cutting marble (although there seemed to be a wealth of information on how to cut granite or cultured marble). I started to think that maybe this wasn’t a DIY project and called around to local countertop fabrication shops only to find out that what they wanted to cut it was nearly 6X the amount I paid for the marble or that they would only cut stone purchased from them directly - so back to the DIY route I went.
I figured if Michelangelo could carve David out of marble there had to be a way I could employ the modern technology at my disposal to shape my marble slab into a much less intricate vanity top. So here’s the process that worked for me and a few tips for other DIYers looking to take on something similar.
Step 1: Setup and Layout
Our setup consisted of a couple of sawhorses with some sandbags set on top and the marble slab balanced onto of the sandbags. The sandbags are there to absorb the vibrations of the cutting tools and avoid cracking. The layout was done with some basic measuring tools, a permanent marker, and painters tape. I made my cutting marks directly on the painters tape and left it on the marble as we cut it to help avoid chipping the edges.
Step 2: Cut
This was by far the most terrifying part of this project ... breaking out the power tools and cutting out our slab. We purchased diamond blades for the circular saw and angle grinder and a diamond hole saw bit for the drill. The circular saw was used to cut the slab to size (four straight edges), the angle grinder was used to cut the sink cutout, and the drill was used to cut the faucet holes. We made sure to supply a continuous stream of water on the cutting blade as we went from a squirt bottle so we didn't overheat the marble and cause it to crack. To waterproof our electric power tools we covered the end of the power cord/extension cord with a plastic bag so we didn't get zapped and we also made sure to wear our eye and hearing protection during this process - it was noisy and messy.
(Sidenote: for DIYers attempting something like this I suggest a self-rimming or vessel type sink, an undermount sink would require some serious skill to get an smooth crisp edge.)
Step 3: Sand, Seal, and Polish
We used a wood rasp to knock down the saw blade marks on the visable edges and ease the top edge a bit giving it a slight radius and then we went to town sanding the entire thing with wet/dry sand paper starting with the low grit and working our way up to higher grit until we got our desired finish. To seal the marble and prevent staining we used oxalic acid which chemically reacts with the structure of the marble to give it a nice seal on the surface. We found the oxalic acid at a local woodworking supply shop since it's also commonly used to bleach out stains in wood. Lastly we buffed and polished the whole thing with some good old fashioned Turtle Wax to make it nice and shiny.
Ready for some before and after shots of our new vanity?? If you made it through all of that I'm sure you are. Here she is before with the beige cultered marble top:
And here's the after with our real carerra marble top, new vessel sink, and new faucet:
Oh and for those of you who aren't familiar with how our vanity looked before this whole project started check out this post.