Marble stone, etching surface

[Jonovdh]

Hi all

I'm new to this page. I'm in Vancouver Canada. I work at my uncle's stone counter business.

We have a crew of 5 guys (including me) and mostly do single family homes.

We have one high profile profile builder whos client picked a material they called quartzite, but I would more define as marble.

It was probably $38/sf when normally mid range granite by us is $20.

After we installed it we applied a sealer but now 6 months later it is etching, and the builder is now suggesting we didn't seal it properly. The entire job was over $13k.

How liable are we as the fabricator, considering we didn't pick the material? Also the relationship we have with the builder is important and somewhat political.

Does anyone go through this type of thing with these expensive exotic materials? It's like the fancier and more expensive, the worse.

[ageless]

Sealer will not stop etching. What was the name of the material? Very common for suppliers to sell a dolomite marble as a quartzite.
You can polish the etches....but anything acidic will cause more.

[Mitch@ASW]

Marbles WILL etch, no matter what. No sealer can prevent it. It will also scratch very easily. Explain that to the builder nicely, and if he's still upset, offer to polish it out. If you're uncomfortable with face polishing a marble, there are step by step directions in the members area that are fool proof. Reach out to Cameron Demille (easystonecare.com) for some of his MB-20 or MB-22, it polishes to better than factory! Good luck, these situations are always a bit touchy.

[Jonovdh]

Thanks, that is a great start!

Sometimes we price the jobs before we even see the material. Then it arrives to the shop paid for and we find our selves not wanting to make them upset but still try to educate them of our initial assessment.

Having it polished is an option then I may suggest it. Either complimenty or as an extra service.

[Jonovdh]

It was called frozen grey. Here are a couple links to pictures.

[Mark Meriaux]

Here is a helpful Technical Bulletin regarding Quartzite.

Quartzite Need Not be a Confusing Stone

You can perform a couple of simple tests yourself and potentially save yourself and your client some aggravation.

[intellistone]

For future marble jobs, I recommend you to create a form that customer needs to read and sign.
It can explain the type of stone and how to maintain its beauty.

[Alex DiPietro]

In my opinion you are responsible for setting the expectations. If you determined it was a marble you should have alerted them to the issues. Furthermore suggesting a honed finish would be a good idea as well. If the builder is pissed and you want to salvage the relationship maybe offer to hone the kitchen at your cost...

We install more marble than granite in kitchens. (say 10 slabs of marble for every slab of granite). Very few problems with surface performance, mostly because we let people know what to expect.

[Jonovdh]

Hey guys wondering if I can get a little more advice on this:

1) Does quartzite Etch or if it's etching and means it's not quartzite? That it is marble if it etches?
2) how does etching occur? Can happen over time just with moisture in the air and over the lifetime of the product? Or does it need to come into contact with something acidic like lemon juice Etc?
3) what is the best way to protect material from etching?
4) the best treatment for an etched surface already installed is to home or polish it? What will cause least amount of wetness damage to the Finish areas in a house which has been moved into.

Thanks guys

[Mark Meriaux]

1)True quartzite won't etch with regular household acids. A material that a supplier has mis-labeled as a quartzite might.
2) Etching is a chemical attack - acids attack calcium-based minerals in the stone. Neutral pH liquids will not etch.
3) Education and prevention are best. Clean up acids immediately and/or neutralize with baking soda.
4) A professional restoration company can re-polish the surface back to factory finish. Many clients like that a honed finish may make etches less noticeable if they aren't going to be diligent with item #3 above. A refinishing professional will mask off any areas to protect against water used in refinishing.

Here's a great article about Quartzites and mis-labeled materials:
The Definitive Guide to Quartzite

The above article was turned into an MIA+BSI Tech Bulletin that you and your staff should read:
Quartzite Need Not Be a Confusing Stone

[ufGatorHarv]

Here's a great article about Quartzites and mis-labeled materials:
The Definitive Guide to Quartzite

The above article was turned into an MIA+BSI Tech Bulletin that you and your staff should read:
Quartzite Need Not Be a Confusing Stone
[

I can't recommend that article enough. I reference it not once but twice on our website, and again to anyone who tries to tell me Super White and a few others are quartzite. You have to educate yourself, then educate your customer.

Remember, there's no such thing as "soft" quartzite. It's either quartzite, and won't react with acid, or it marble. Period.

[Jonovdh]

You have been extremely helpful all of you thank you very much.

One last question how does sealing factor in. With ceiling it will cause the water to bead and not penetrate as easily. Should the sealer not have this effect on say lemon juice or other similar liquids?

Thank you again.

[Dan R.]

Water is not the issue with etching.
Etching is an issue when the marble (7 pH) comes in contact with and acidic solution (anything less than 7 pH) The calcium in the stone is eroded by the acidic solution. This manifests itself as a dull water spot looking mark. Although it may look like a water spot, do not be fooled. What actually happens is that the acidic solution eats into the marble ever so slightly. So slight that it can not be felt by human touch. What this ersiuon does accomplish is to slightly abide the surface, making the light refract off the effected area and not reflect off the shiny intact surface. Thus causing a difference in sheen and looking like a water spot.

Sealing will not help with etching, as etching is a chemical process that occurs in nature. Sealing is a mechanical process that eliminates or slow absorption into the stone. Two completely different issues.

[Jonovdh]

But should sealer not protect from the lime juice/acids? Or is sealer only a first line of defense.

[Dan R.]

Sealer protects against staining.
STAINING AND ETCHING ARE 2 COMPLETELY DIFFERENT & UNIQUELY SEPERATE ISSUES, WITH DIFFERENT & SEPERATE CAUSES AND SOLUTIONS.
Sealing does not offer any protection against acids.

Sealing fills the microscopic void in stone with very small solids that cure hard and block intrusion by liquids.

Etching is a chemical process where the acidic substance actually erodes the calcium based products, like marble.

You need to understand the differences between etching and staining, their causes and their preventions.

[Dave.Scott]

At the risk of seeming to some that I am splitting hairs........

Water is a miraculous molecule, because of it's properties, it can act as an acid and as a base simultaneously.

Ill let that sink in.

Because it is a great solvent, and especially, when it has been through an RO system it can act very much like an acid.
Sealing marbles and calcite based stones is so very important because of this.
Etching can occur when water stands for longer periods of time on marble.

Also, be aware that water is rarely at a perfectly neutral 7 pH. The normal range for pH in surface water systems is 6.5 to 8.5, and the pH range for groundwater systems is between 6 to 8.5.

[Mark Meriaux]

...Etching is an issue when the marble (7 pH) comes in contact with and acidic solution (anything less than 7 pH)...

Picking nits here, but Calcium Carbonate (Calcite) in marble is closer to a pH of 10, which makes it a weak base. That's why it's a common component of antacid pills.



Building on Dan's explanation above....

Sealing helps to prevent liquids from going IN the pores of the stone.
Etching occurs ON the surface layer.

[Dan R.]

Mark, thanks for the clarification on the pH of marble. i was always told it was pH neutral (7ph). I did not realize that it was that far up on the scale.
Great thing about the SFA, always learning.
Thanks for today's lesson.

[cbolton]

Hopefully you have been able to come to a positive agreement with your builder, but if you are still trying to here is my 2 cents.

We have a sales staff at our company and when these "quartz" materials first started hitting our inventory I went around and around with them on properly identifying them and informing customers what they could expect from the material. In my opinion it comes down to whether the builder can be convinced you properly sealed the material, which i personally believe is the limit of your liability. As you didn't sell the customer the stone, it wasn't even in your ability to inform them of the properties of this material. Present the builder with the information you have learned as a way of showing them the difference between etching and staining. Hopefully you can get them on your side of the issue.

That being said, as others have told you it is imperative you educate yourself on identifying the materials you are working with. Buy a Mohs testing kit. They are inexpensive and when you show someone a #5 scribe scratching the surface of a material labeled quartzite it impresses on them the fact it is in fact not such. Until then, if you start sawing a material at a speed you would saw granite and your saw doesn't amp out its not quartzite.

Do what it takes to save your relationship with your builder. If you have never surfaced marble on site, my suggestion is hiring a professional if that's what it comes down to. If you try it you will then be opening yourself to a whole lot of liability that won't be worth the cost of hiring it out.

[dustinbraudway]

All good points here. But most tend to forget that no marble is the same and all act and react differently at completely different rates of time for etching . Test all your stones and educate your clients. Marbles from one continent can differ from marbles from another. Again it comes down to education and testing so you can give the clients the best advise.

[Express Granite]

What kind Of test everyone does on the marble materials the most common few to test please list so I can test on our materials thx

[Express Granite]

Based on this chart is the ph 0 will have higher etching than ph 10 am I right can I give this information to customer for their guidance.

[Mark Meriaux]

Based on this chart is the ph 0 will have higher etching than ph 10 am I right can I give this information to customer for their guidance.

If you believe that giving your customer a pH scale of common solutions will be helpful, then give them this information.
I believe that the more important message is that acids (low #s) react with bases (high #s) - this chemical attack can leave an etch.
Just because the solution is closer to a 7 (neutral), it still can cause an etch.

[Express Granite]

Do you have a general terms what not to use or combine may cause the etching. To customer alot of time we told them would not get it even us. As a fabricator still had a hard time to determine what may or cause that. The more and more us fabricate marble to me just want to see if I can give the customer something to avoid as guidance . Anyone have a list want to share will be appreciate it thx

[Dan R.]

IMO, it is impossible to give a complete list. We warn against anything lower than pH 7. Marble is great , but is definitely not for everyone.