KS-$V Castable Refractory and SuperPlasticizer

[OldBaker]

Looking to do a cast oven with KS-4V Castable. What I am trying to find out, and have been unable to find the answer to, is how much plasticizer would I use per 55 lb bag?

[david s]

I don’t think you should use any superplasticiser because it’s effect on calcium aluminate based castable is far more powerful than when used with Portland cement based castables. You run the risk of the materials separating. I use a little with castable but only where the moulds have both inner and outer walls. If placing over a hump mould the mix will slump. I generally only use less than half the recommended amount and only where I have both inner and outer walls.

I could only find the Safety Data Sheet on that product not the specs. Make sure it’s a dense castable not an insulating castable. The density should be around 200kg/ m3 (2 kg/ L)

[OldBaker]

Thanks David. KS-4V is a dense castable. My concern was material segregation or having too much slump so that was my reason for asking for information. I wanted to use less water in the mix and also have it a little looser but without causing it to slump too much. I do have extra material and could experiment a bit and if necessary I could just go with the manufacturers recommendation. Again, Thanks for the info.

[fox]

Castable is not always easy to work with and is normally mixed very dry (about 4lt per 25kg) it works extremely well when vibrated into a mold but can be tricky to lay on a surface.