Stone Master Molds Rubber Molds for Concrete, River Rock Flat Mold

Stone Master Molds Rubber Molds for Concrete, River Rock Flat Mold


River Rock is a naturally river-worn, full-size stone, varying in sizes up to 10” in diameter, with thickness varying from 1-2.5″ in the center. Each mold makes approximately 1.75 square feet. River Rock is most often used on log cabins and coastal homes, on the outside and inside. It is gorgeous on fireplaces, too. Stone Master’s rubber molds are made from plastisol, which requires no release agent and will last for hundreds of pours. Each mold measures approximately 23.75″ long by 11.5″ wide, by 2.25″ thick. This mold includes recycled plastisol. Made in the USA, both materials and labor. Available in 5 unique versions, with no stone repeats. Matching River Rock corner molds are also available.

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2 - 3



4 - 6



7 - 99


  • Professional grade rubber mold that will last for hundreds of pours, created from natural stone to reproduce the natural stone's finest details
  • Made in the USA from plastisol rubber, including recycled plastisol
  • No release agent necessary, saving you money, time, and clean up, as well as easy, clean release of face color pigments, unlike plastic molds,  urethane molds, and silicone molds
  • Each of 5 available mold versions you purchase has one-of-a-kind stones with no repeats
  • Matching River Rock corner molds are also available

5 reviews for Stone Master Molds Rubber Molds for Concrete, River Rock Flat Mold

  1. Gayle

    These are pricey but worth it. Compared to other molds I’ve been trying, these are better and more durable.The rubber seemed cumbersome and heavy to me at first, but the finished stone pops right out; you don’t run into the same issues that you do with cheaper plastic molds. It’s much easier to get a result that looks much more like authentic stone.They’re also easier to clean off afterwards (which is something you have to consider–any residual concrete will result in a less authentic effect next time), because of the flexibility of the rubber.Also, the fact that they’re rubber, not plastic makes them a lot harder to break (and I’ve kinda tried. Lol).

  2. Aura Castellese

    I have used different products to make stones, but this rubber mold is the best of the best. I highly recommend this product. Do not be fooled regarding the hard plastic molds or some of the others being sold, which are made from lower-quality materials. Again, I highly recommend this product.

  3. Sharon P.

    The Veneer Stone Rubber Mold is so cool! I purchased in beginning of summer. Living at the shore, we’ve got sand, but no rocks to be found. So to edge along the back garden I began mixing Quikcrete from H.Depot in buckets. The mold has 7 diff. shapes. I bought the brown cement dye adding just a little each load so all rocks wouldn’t look the same color.(bottle says use all per bag of cement…I’ve used 5 bags of cement and still have dye left) I’ve made 158 rocks to date, looking to make more. Friends thought they were real rocks! Pour on batch at 7am, firm enough to pull out of molds by 2, next batch ready in 6-7 hours. I highly recommend!! *****

  4. Mari B.

    Easy to take out from mold

  5. greatsite

    I use mold #5 to make river rocks for my custom paintings. My customers are amazed that these were made from a mold. I use white mortar mix for stucco Type S and they dry so very hard. For my rock painting I take out of after 48 hrs and round out the 90 degree edge to make it more complete rocklike. If I wait any longer then 2 days it’s more difficult to shape that rounded edge. Highly pleased and so easy. Love this rubber mold.

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