Castable Refractory Question


About to mix the castable refractory for a Cupola and the directions suggest using a cement mixer. On the Brickwood site I found another set of directions that recommend NOT using a cement mixer because it increases the heat. It is summer and the ambient temperatures are hot. What is the best way to mix the refractory, mixer or by hand?

Thank you in advance.

Hi Tom, and welcome to the BrickWood forum.

Both things are true. You get the best mix with a mechanical mixer, especially considering that you have a relatively large quantity of a heavy material that has to be mixed all at once. And, the mechanical action of the materials mixing comes with a good amount of friction, which heats up the mix and shortens the “window” for casting to a point where you might have trouble.

So, take your inspiration in a tall, cold drink of water. Measure out the water for the mix in one of your 5-gallon buckets, and mix with plenty of ice. The heat generated by the castable will be absorbed by the ice-cold water, thus extending your casting time enough that you can work with it.

Hope this helps, and hope we’ll see you often around here. Good luck!