Carthalite - any old timers know how to make it?

[Stephen Tashiro]

The "older than dirt" thread prompts me to ask if there are any old timers who know the technology for making Carthalite, ornamental concrete, which is the subject of this PDF: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=15&ved=0CIQBEBYwDg&url=http%3A%2F%2Fwww.wichita.gov%2FGovernment%2FDe partments%2FPlanning%2FPlanningDocument%2FAmerican %2520Bungalow%2520article-Carthalite%2C%2520Wichita%27s%2520Beautiful%2520Co ncrete.pdf&ei=77cWUqqqFcrCyAHEJg&usg=AFQjCNHLEJqk0w3yyQCfFh0X65uSBRSyyA&sig2=A9ipNjmj6x83tusBM1wT_g&bvm=bv.51156542,d.aWc&cad=rja

[Jim Koepke]

A quick search of > carthalite < indicates it was just sand, cement and crushed glass.

Sounds like fun.

jtk

[M Manlove]

I am a lifelong(66) resident of the Wichita area. I am familiar with all the remaining carthalite in Wichita. It does use finely ground glass as a coloring agent. It was basically white portland cement with ground glass as one coloring method. There were 13 structures in Wichita and one out of Wichita decorated with it. Eleven remain today.
Carthalite was made by the Cement Stone & Supply Co. At one time they were purchased or absorbed by Lusco Brick which is still in business here. Carthalite was no longer made by then. Restoration work over time has been done rather poorly until King Construction took it on in about 2009 and got it right. Wonderful work. I think they are from Hesston , Ks. If you have some specific questions I probably can find the answers.

[Stephen Tashiro]

. If you have some specific questions I probably can find the answers.

I've never seen carthalite first hand, so I have a very basic question. Is the finished product a result of polishing the surface of the concrete after it hardens? Or is the glass exposed simply by doing minor clean-up of the surface of concrete that has been cast?

[M Manlove]

The concrete wasn't polished. The color comes from the glass and other pigments used. Obviously a lot of color comes through. There is probably more glass and other pigment than one would first imagine. To the best of my knowledge no special cleanup of the finished concrete was ever needed. Carthalite is impossible to describe. You just have to see it. I have no doubt that you could make it yourself. Find white or very light portland cement. Lot of glass well ground. I have always been surprised that this was never done elsewhere. The results are stunning and the color lasts for ages.

[Stephen Tashiro]

Another thing I have never seen first hand is "ground glass". Is it smooth like river rocks?

Of course, I have seen small pieces of broken glass. However, I can imagine using sharp pieces of glass in a concrete object unless the surface was polished with abrasives - (or the concrete was used in a Berlin Wall type application).