We've gotten a lot of hands-on experience with Agr-Rok the past few years as we answer questions from interested potential customers regarding whether the super-dense cement overlay will work for their particular application.
We've had some fascinating requests, including some really tricky ones like seeing if we can use a combination of Agri-Rok and biological sealers to cover an ocean sea wall and repel barnacles (this one's still in progress). Brainstorming sessions have sometimes gotten pretty interesting as we try things like mixing a colloidal silica troweling aid into the dry mix instead of water to see if it will become even denser. Our experiments have sometimes succeeded and sometimes failed - we haven't yet been able to find the right product that will reliably color the overlay without weird marbling or floating issues, for instance.
In the process we've learned some great tips.
1.) Agri-Rok gets stronger the less water you put in it, so don't add more. When first mixing, it doesn't seem like the correct amount of water is enough since the product initially looks very dry, but when mixing continues the dry mix suddenly melts into the perfect chocolate-milkshake consistency. The instinct to add more water at the beginning always causes problems, so the key to the right blend is to measure the water properly and resist the urge to add more.
2.) Temperature, temperature, temperature! The correct temperature of water and base floor is important to a good fast set. We once laid Agri-Rok over a newly-installed cement slab during a very cold February. There was a heater in the room, but everything was still icy to the touch and the Agri-Rok stubbornly refused to set for several hours. Considering it normally hardens to the touch in about half an hour, this was unexpected and set back our finishing process by a whole day. Using very cold water in the mix can have a similar effect, slowing the set time. Hot water will make it set too fast, before it's properly mixed. So keeping the temp at 60 degrees or more for the water and the floor definitely improves the results.
3.) Don't overmix: you'll whip bubbles into the overlay and it takes a lot more raking/troweling to get them to all rise to the surface and settle. Once the dry mix and water melt together and turn into milkshake consistency, pour it down and start raking. Otherwise there will be a quantity of small bubbles that need to be hand-troweled out, which is a pain in the neck for what is otherwise a ridiculously easy install process.
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