Deflocculants in the DIY fireclay insulating refractory

[oxbowfarm]

Just a note for other newbies like myself. I've been casting pieces of a 6 inch Peterberg batchbox using matthewwalker's 14:14:1 fireclay:perlite:furnace cement recipe.  Since I've made some DIY sodium silicate I added in some of that as I was adding the furnace cement to the clay.  This dramatically improves the workability of the fireclay mud from a stiff sticky backbreaking mixing job to a smooth buttery flowing mix from the addition of 1/4 part sodium silicate.  Just from a ease of mixing standpoint, I think it is a huge benefit to add this to the recipe.  This may or may not be the case for anyone else depending on the chemistry of the fireclay you are using, but for the stuff I found it was like magic.  Turns out that sodium silicate is one of the basic go-to deflocculants in ceramics, so that pretty much explains my experience.  It looks like washing soda, sodium hydroxide alone or TSP would work equally well if you don't want to buy or hassle with making sodium silicate.

Hopefully this is helpful to someone else.  

[dino]

Hi,

with the sticky bubblegum-like clay in my garden I experienced something similar by adding woodash and even portlandcement.