Will it adhere [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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12-18-2006, 01:43 PM
Originally I was going to set these 2 kinds of marbles in unmodified thinset. After talking to a tech guy from shluter he told me I should use unmodified thinset instead of modified thinset becuase I willl be using shluter ditra under the marble. I never told him that there was a fiberglass mesh with epoxy or polyester on the back side of the pieces. One piece has gritty sand sprinkled on it as well. The other one doesnít. I was going to use unmodified thinset until I read this article here http://www.natural-stone.com/failure1.html . This is what it says

Changes in Fabrication
Adding of polyester and epoxy coatings with fiberglass mats on the back of the stone is a change in fabrication.
Instead of bonding the setting adhesives to the stone directly, the setting materials are now bonding to other than the stone surface.
Portland cement including modified mortars will bond to stone surfaces.
Portland cement will not bond to polyester.
Portland cement will not bond to epoxy.
Portland cement will not bond to resins.
Portland cement will not bond to mastic.
Entire projects have failed due to lack of communication of changes in fabrication.
Epoxy will bond to polyester.
Epoxy will bond to epoxy.
Epoxy will bond to Portland cement.
Epoxy will bond to resins.
Epoxy will bond to mastic.
The theme here is Portland cement will not bond to epoxy or polyester resins, and epoxy will bond to Portland cement.
The tile industry has not printed this information, with the exception of a cartoon created by Donato Pompo, CTC, which was published in Tile Industry News.
Broadcasting sand into resins or epoxy does not make the backside of the stone compatible with Portland cement mortar.
If in doubt as to what will effectively bond to changes in fabrication, we encourage you to work with your favorite adhesive manufacturer.
Send the stone to the adhesive manufacturer for testing in their laboratory.
The adhesive manufacturer will confirm to you what setting material will work best with altered natural stone surfaces.
This process includes thinking and working with agglomerate tiles and stone.
You, the importer, are liable for changes in fabrication.
You are responsible to educate installers of altered stone surfaces which have occurred from changes in fabrication as to what workmanship requirements are necessary in order to make the installation last and perform.
A good example would include Bob Young's articles on green marble.
Stones subject to curling and crowning require special attention to setting materials that will not contribute to/or aggravate the moisture sensitive stone.

Oh, I donít have to use epoxy know for the entire project do I. This is a big project I have. This is what it looks like on the back side of the pieces though

This one has the gritty sand on the back of the pieces.

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12-18-2006, 02:11 PM
Will, Schluter doesn't want you to use a modified thinset over Ditra due to extended "drying" (not curing) times. Since un-modified thinsets will not stick to your proposed tile, that leaves you with epoxy. Epoxies do not dry, they cure.

Or, pick another marble product without the coatings on the back.

12-18-2006, 02:17 PM
Well, I already purchased so it looks like there isn't anything I can do about it :bonk:

12-18-2006, 02:54 PM
Is the Ditra already down? You could switch to backerboard and use a modified thinset.

You could use a modified thinset over the Ditra. You'll have to give the tile lots of time to dry (think days or weeks), and Schluter won't warrenty it.

12-18-2006, 04:16 PM
Will modified thinsets bond to this epoxy/polyester stuff either. I wonder if modified thinsets will even adhere to it. In that article it say this "Portland cement including modified mortars will bond to stone surfaces". I think the article is including modified mortars with nonmodified. I think they are anyways. The article only gives epoxy as being the way out. Thanks for your help as always :) :) :)

12-18-2006, 05:24 PM
Where's Dave Gobis when we could use him?

I'd be really surprised if a good modified mortar wouldn't stick to it, although I'm no expert when it comes to that.

12-19-2006, 12:24 PM
Any opinions. I am sure somebody here has used or knows something about this stuff. Thanks