Granite, concrete, masonry, marble—heck, they’re basically all the same, right? Hard stone-like materials that can be used for all sorts of building projects. So if I go to the hardware store and pick, for instance, a product designed as a “structural adhesive for concrete”, it should work just fine on my limestone fountain, right?
What? Why not? Well, let’s first look at why folks choose concrete over a natural stone (like limestone). Most often—it’s a cost issue. Let’s face it, stone is expensive! But when people do choose natural stone, it’s usually for one reason—- The Look. Concrete and regular masonry just can’t compete with the natural variability, beauty, and overall aesthetics of natural stone.
So, back to the adhesive example above. What’s wrong with using the off-the-shelf product? Perhaps nothing, but remember why folks usually choose concrete—low cost. (They usually don’t choose it for its looks—concrete really isn’t all that pretty! ) So what’s an important property for an adhesive for concrete? You guessed it—low cost. And how do some manufacturers lower the cost of their glue? By using low cost raw materials, of course! And one of the lower-cost raw materials that is commonly used is something generically termed “hydrocarbon resin”. (A rough analogy might be 10-40 motor oil, although that material is highly refined and thus NOT “low cost”!) But the key thing to remember about the hydrocarbon resin is this: you basically have oil in your adhesive, and what do you think will happen when that adhesive is applied to your beautiful natural stone? The oil is going to seep into the pores and cause a nasty-looking stain. And if that happens—chances are that stain is going to be permanent. Not too big of an issue with plain-looking concrete—- but fatal to the good looks of your limestone fountain!
So now you know why there are products developed specifically for use on natural stone. These products have been developed and tested to assure that they don’t contain any hydrocarbon resin constituents that may seep into and stain natural stone.
Always insist on products designed and tested for use on natural stone. Your fountain will thank you!!