How to Choose Calcined Clay for Your Field

We have been big fans of DuraEdge engineered soil products for many years. Their approach to innovation through science aligns with Beacon’s core belief to always innovate in search of better solutions (read more about DuraEdge here).

DuraEdge released their new line of ProSlide calcined clay conditioners and ProDry. These products spent 6 months in research & development — which included field testing at the MLB level as well as testing in the lab for refining. Calcined clays are made of specific earthen clays, like montmorillonite, that are fired to 1200°-1400°F (DuraEdge is fired to 1400°F) in a rotary kiln, crushed and screened to specific gradations. The end product gives groundskeepers products that stay on the top surface longer, have less contamination, and less migration.

DuraEdge InfieldThese calcined clay products work great when used as a topdressing on an infield skin either alone or — better yet — blended with expanded shale topdressing materials to give the groundskeeper the desired field surface conditions for moisture management. In the past, calcined clays were typically sold as an amendment to till into your infield soils in large amounts to improve infield soil performance. Science has proven, however, that it is better to alter soil with soil for optimal field performance and save the calcined clays to be used as the topdressing layer (or at least as part of your topdressing layer). Beacon and DuraEdge both recommend that these calcined clay products only be used on the infield skin surface as topdressings or to dry an infield when immediate play is needed after a rain event.

An infield topdressing layer should be approximately ¼” to 3/8″ thick. Anything deeper can negatively impact player traction and the bounce of a ground ball across the skin surface. Calcined clay, as a topdressing, helps to create a buffer zone between the players’ cleats and the infield soil beneath the topdressing. This layer creates the perfect sliding surface for a player provided that you keep a firm infield soil beneath it. The layer also helps to control moisture in the infield. It can allow you to walk on the infield when it is wet without the infield soil sticking to the cleats (provided you have properly balanced infield soils beneath it). The topdressing can also hold moisture on the surface longer into a game, thanks to its moisture storage capacity.

Five options…

Fair BallProSlide ProfessionalProSlide PlatinumProDryDuraEdge Pro slide Play ball
DuraEdge offers 5 different gradation choices for your infield skin:

  • FairBall – The widest spread of gradation going from very coarse to fine particle sizes and everything in between. This is the most economical of the four calcined products and is great for those organizations that have tight budgets and still want a topdressing.
  • Play Ball – Developed for blending with the ProSlide 6×30 Expanded Shale Topdressing for the optimum in topdressing performance.  Both products share the same gradation range.
  • ProSlide Professional Calcined Clay – Cutting out the largest and finest particles leaves just the middle particle sizes to provide a more consistent surface. This product can be perfectly matched with the ProSlide Topdressing 6×30 Expanded Shale.
  • ProSlide Platinum Calcined Clay – This product is meticulously screened to one screen size promoting the most uniformed and durable calcined product available and creating the most professional surface possible.
  • ProDry – Is not like other very fine and dusty calcined drying agents on the market. It has the highest absorption percentage in DuraEdge’s line of calcined clays. It is engineered to the size of a coarse sand, which eliminates annoying dust, which allows this material to easily mix into your existing topdressing without the detrimental effects that other, finer and dusty drying agents bring to a field. That means you won’t need to scoop it off the infield after a game. Just drag it right into your topdressing.

A few recommendations…

All five of these options can be used as a “drying agent” as they all have the strong capillary action to suck up water.

I typically use the professional grade as our drying agent at or test facility since it blends in the best with the gradation of our expanded shale topdressing on our infields.

As for topdressing choices… If you have a tight budget, I suggest you stick with the FairBall product. It’ll give you the most bang for your budget dollars. For those with more money to spend, Professional topdressing will provide a fantastic finished surface for managing your infield moisture. The Platinum, with its sole screen size, provides the smoothest finished surface with a fine manicured appearance. Like playing on a surface that is as smooth as glass.

Paul Zwaska (contributor)

A former head groundskeeper for the Baltimore Orioles, Paul has been a frequent contributor to Beacon’s Ballfield Blog and other resources and products. Among other contributions to Beacon, he authored Groundskeeper University, the pioneering online ballfield maintenance training venue.