Studio stone mixes

Posted by Angel on December 10, 2001 at 17:16:42:

In Reply to: Re: stepping stones posted by Gary Dodge on December 04, 2001 at 16:52:35:

: Q2: Is it neccessary to bring the stones inside in the winter since I live in Wisconsin. What type of cement do you use?

: A2: In theory if you do everything correctly and seal the stone with a product like Thompsons water seal after letting it cure for 30 days after pouring, you should be able to leave it out. Making sure that you have good drainage under the stone, like a gravel bed is a definite plus.

: In the final analysis that "if you do everything correctly" thing is a biggie! If you have put a great deal of work into a particular stone, that may not be the one to test your technique on. Too little or too much water in the mix can be fatal to your stone.

: We use DiamondCrete.
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It's not my place to tell people what to use. The amount of work that goes into a stepping stone is considerable when done correctly. I wouldn't use a product that I know has poor ingredients and will be a temporay structure at best. I started out doing research (and found Cole Sonafrank's information site) looking for a substitute for the smoothness of studio mixes (which are ridiculously expensive ) that also had a permanence factor. In my opinion, durability is one facet of art....unless it's edible.

I get hundreds of e-mail and forum replies from people who have had heartbreaking problems with studio mixes. It's even worse when you give away or sell a stone that crumbles or cracks and falls apart...really embarrassing and discouraging. No amount of proper drainage, cure time and sealing will save a gypsum-based stone. They're easy to make, but don't last. Diamondcrete actually advises that their stones be taken inside in winter, but I will tell you that even a humid climate without snow etc. will degrade them within 6 months to a year. Even if you use less water than recommended, the basic flaw in material is still present.

The strength of a stone is directly proportional to the water/cement ratio. ANY concrete mix is compromised by excess liquid. In the case of ordinary concrete it increases shrinkage and promotes cracking of the glass. In Gypsum mixes it leads to crumbling and/or glass popping OUT of the stone.

Making a fine, pourable, fiber-reinforced concrete is no harder than making biscuits once the ingredients are assembled. Durability is part of their beauty. I just want people to have the information on which to base their choices of materials.

Sealants come in many forms. A good, water-based sealant that's made for concrete is necessary. Thompsons and other brands will cloud the glass and dull its beauty. There are others which will not, but we wipe the glass surface after applying them to help prevent ANY over-clouding. Get your information and experiment with small stones before moving into the major sizes.