Sealing Marble: The Acid Test

I wanted to seal the marble with something to protect it against some of the nasty elements of the kitchen. I have a 111 year old marble vanity in the bathroom that is doing great but the bathroom doesn’t have red wine and tomato sauce in it. Well, at least not normally {cough}. I forgot to ask the guys I bought the marble from if they recommended anything.

So last Friday I posted a message over at The Old House Web asking if anybody had used a particular product they liked. I got a number of responses but most were along the lines of, “Oh no, marble in the kitchen, that’s bad”. I got the standard responses like “Marble is a soft stone”, “Marble stains easily”, “Marble chips easily”. It’s like everyone has a set of Marble Talking Points they read from. One person even suggested that I keep it covered all the time unless company comes over or something. Isn’t that the idea behind those tacky plastic covers people used to put over sofas and lamp shades.

First, let’s start with “Marble is a soft stone”. So T F what. It’s a stone for cryin’ out loud. Saying marble is a soft stone is a bit of an oxymoron, don’t you think? Yes, in the whole family of stone marble is not as hard as others, but in the context of a kitchen counter it is a hell of a lot harder than other materials. It’s a freakin’ rock people!

{I want to take a moment here to say that if anyone says that granite is harder than marble as a comment, your comment will be deleted for the sheer stupidity of it.}

Now for the “Marble chips easily”. Well, let’s go back to the whole rock thing. Marble is a rock and rocks chip if you bang on them. Here’s a helpful tip: Don’t bang on it! For that matter, don’t bang on your Formica, linoleum, tile…..in fact, don’t bang on your counter tops with hard things that are likely to chip, ding, or scratch them. It’s a little something I like to call “common sense”.

Finally we have “Marble stains easily”. The word “easily” is, of course, a relative term. A lot of things stain, and yes marble does stain. However, there are ways to treat the marble so it doesn’t stain as “easily”. It’s called a sealer and that was the whole point of the question I posted on The Old House Web forum. You apply the sealer to the marble and it protects the marble for several years. Of course, even if you do seal it there is always the little trick my mother beat in to my brain everyday for 18 years, “Wipe up that mess! Is this how I raised you?!?!” That’s right, you guessed it, don’t leave heaping piles of rotting matter on the counters and they won’t stain.

So, anyway, I looked locally and found 3 different stone sealers. The people who sold me the marble buy a product called Stone Shield 611 but the receptionist told me they buy it in bulk and don’t sell it retail. A tile center had another product, and I don’t recall the name of it, but it was really cheap and I just didn’t feel good about it. The sales girl had never used it and knew nothing about it. Oh, and when I asked for a price on marble tiles because I was thinking about putting them in the foyer she said, “You know, marble is a soft stone and stains easily”. It was all I could do to keep from punching her in the face. I honestly felt like asking her if she was issued a set of Marble Talking Points some place.

As another aside, I saw on This Old House last week or the week before they took a tour of the recently renovated Union Station in Washington DC. The football field sized floor was done in white and black marble. It looked stunning. And if you like Beau Arts style architecture, it doesn't get much better than Union Station.

At the only Home Center in town called Pierson’s they carried a line of products called Stonetech. I bought a 1 quart bottle of the Stonetech Professional - Maximum Bullet Proof Sealer. The guy who sold it to me said he used it many times professionally and swears it’s the best on the market. At $48 a quart it better be the best. To be honest, Pierson’s is notoriously over-priced so I wouldn’t be surprised if I could get it much cheaper outside the area. It took about a third of the quart for 2 applications on the counter and it says it lasts 3 to 5 years. So I bought about a 12 to 15 year supply.

Naturally, because I’m neurotic and obsessed about these sorts of things I wanted to perform a test to see how well it works. When I picked up the slab they gave me some scraps of marble from the same slab because I want to do some tests with the router before I cut the hole for the sink and finish the edges. I used a piece of that for the test. I wrapped a piece of electrical tape around the middle and left one side untreated and treated the other side the same exact way I treated my marble slab. So here’s results.

At first I tried basic spill tests for 10 second durations. I spilled wine for 10 seconds and wiped it up. That was too short of a time and didn’t effect either side at all. I then went to 1 minute and that didn’t do a thing to the untreated side either. So I went to 10 minutes as the first test period. I used red wine, tomato paste, and lime juice. I also did a cutting test and a chip test. After the 10 minute tests I did a 1 hour test with all the ingredients and set the wine glass in the whole mess.

Here’s the results.


Here it is before any tests. The treated side is on the right.


Red Wine


This is after about 7 minutes. You can start to see some change.


After 10 minutes. I only rinsed with water between each test. I'm not sure how well it shows up in the pictures but the untreated side has some discoloration.


Tomato Paste

Ten Minutes Later.


I cut the lime on the marble and I wasn’t careful at all. I cut hard enough to slice through the electrical tape. There are a few marks in the marble. To be fair, if you’re going to use any counter top surface as a chopping board, unless it is designed for that, you should just get plywood counters.




The Lime Test

Ten Minutes Later.


The Chip Test. I smacked it good several times with the blade of a standard flatware eating knife. There are some minor nicks. Again, though, if this is how you treat your counters then get plywood.


This one was really telling. Before I did the final hour long test I took the tape off. The difference is dramatic. It is obvious which side was treated.


Here is the final torture test. That is tomato paste, red wine, and lime juice with the wine glass smooshed in to it. It sat like this for more than an hour.


Afterwards I rinsed it with cold water.


I think the treated side looks pretty good and it will lighten back up after it dries. The day I picked up the slab it was raining and they had been storing it outside. After a few hours of being in my house it lightened up a bit. The next step will be to get some marble cleaner and see if I can clean the untreated side any.

Granted 10 minutes isn't a long time, but it seems to be a good test. If I was cooking and I spilled something I would probably wipe it up within 10 minutes. The hour long test was to show what would happen if you left something there during dinner and then wiped it up afterwards. I think I'll try over night next and see what happens.

(Read about what happened The Next Day)