On Sunday, September 30, 2012 1:36:58 PM UTC+1, Harry Davis wrote:
meow2222 wrote in

:



On Sunday, September 30, 2012 1:00:15 PM UTC+1, Harry Davis wrote:

Hello, I'm reconcreting a small front garden and considering

colouring the concrete, probably a pale yellow, using cement colourant.





Can someone tell me whether it's sensible to use cement colourant

with ordinary cheap cement, or does it really only do a good job with

e.g. Portland cement etc.?



I thought portland was ordinary cement, OPC. Colouring pigment works

with all cements, but if you want pale yellow or cream you'd need to

start with white cement.



Thanks for this. My cement bags say Lafarge general purpose, which I

thought was different from Portland, but clearly you are right.



I'm not sure whether it's 'wholly' Portland, though:



http://tinyurl.com/cement701



So this is the wrong stuff? If I used some yellow colourant with it, would

the result be greyish yellow (which would probably be OK), or would

something else go on (as it might for example with some art paints, where

chemical properties can prevent application of standard colour-mixing

rules)?



Thanks again!



Harry

yellow + grey = a warmer tint of grey


NT