I've been trying to find a cement additive to change the color of some mortar, but only seem to be able to find it in liquid form at my local big-box hardware store.
I'm looking for a similar product that can be added to dry mortar mix. Does this even exist? Where can I find it?
Back-story:
I put down a patio of pavers a few years ago and apparently didn't put down thick enough plastic sheeting underneath. I skimped because the area seemed too shady to promote much weed growth. Boy was I wrong. I have major weeds growing through the cracks between the pavers.
My plan is to power wash the patio to get most of the sand out between the pavers, and then replace it by sweeping dry mortar over the patio and then misting it so it will harden and form a barrier for the weeds between the pavers. To get the color right I'd need to mix the color into the dry mortar before spreading it. I'm not sure how well this will work, but I am going to try on a small area first to see how it goes. If anyone sees any major pitfalls with this plan, please speak up in the comments.
Best Answer
I have worked with dry color for concrete. We poured a few slabs and some curb.
The dry power was available at a concrete supply house. It was expensive, but could be bought in small bags if needed. A little went a long way.
The color powder made a huge mess and stained everything. It was the consistency of powdered sugar. You need to mix it really well with the dry mortar or you will end up with varying color. You need to test the color by mixing up and curing a sample as it is hard to know exactly what the color will look like until it cures.
In this case, I would skip the color and use polymetric sand. Something like this: http://alliancegator.com/2011/?p=21