Your Advice Re: HomeBrew Castable Mix Greatly Appreciated

[Killian]

Re: Your Advice Re: HomeBrew Castable Mix Greatly Appreciated

Thanks for the info David!

Too bad about the CSA isn't it? I wonder why CA cement is so much more expensive?

What do you think about the inclusion of potassium silicate as an admixture in a refractory mix? This is sold as a surface densifier, but it is also used to seal radiator leaks and reportedly is an ingredient in refractory materials, at least according to Wikipedia. "Water glass" is another old term for it.

I've also wondered how well lime mortar (straight lime) holds up to heat. My guess is that it is a poor refractory, but I'm sure someone here has a more official answer to this question. I understand that before the invention of Portland cement, lime putty mortar was the only game in town, so it must have been used to build fireboxes and ovens at some point.

[david s]

Re: Your Advice Re: HomeBrew Castable Mix Greatly Appreciated

Thanks for the info David!

Too bad about the CSA isn't it? I wonder why CA cement is so much more expensive?

What do you think about the inclusion of potassium silicate as an admixture in a refractory mix? This is sold as a surface densifier, but it is also used to seal radiator leaks and reportedly is an ingredient in refractory materials, at least according to Wikipedia. "Water glass" is another old term for it.

I've also wondered how well lime mortar (straight lime) holds up to heat. My guess is that it is a poor refractory, but I'm sure someone here has a more official answer to this question. I understand that before the invention of Portland cement, lime putty mortar was the only game in town, so it must have been used to build fireboxes and ovens at some point.

Yes it is a pity about CSA. I think it is a major ingredient used in rapid set concrete. I don't know about the use of potassium silicate in refractory. I use a bit of sodium silicate as a deflocculant in making clay slip, it has many other uses too. The "home-brew you may see mentioned frequently on this site which is 3:1:1:1 sand, Portland cement, clay, lime makes an excellent refractory mortar which works extremely well for a WFO temperature range and can also be used as a castable mix, although probably not as good as a proprietary CA cement based castable.