Re: ATM Sonotube is good for making cement columns...

[astillma@nit.AirTouch.COM (Anthony Stillman)]

Bruce,

You wrote:
...
The second coat is thickened with colloidal silica powder until
it's about the consistency of peanut butter (maybe not quite that thick,
maybe more like mayonnaise).  It won't run or drip, and you can spread it on
with a flat plastic blade, filling in all the "spirals" or imperfections.
...

Sounds great!
So, where do you get colloidal silica powder?

Anthony