A DIY-er, - experienced with traditional mortar grouts, which had worked well, - I am now absolutely sold on Fusion-pro. (Was searching on-line, from epoxy to newer products to... decided to give a try to what is sold in local Home Depots as a ″never needs sealing.″) Sounded alluring and readily available, with no danger of running out of time or quantity. It worked well, - just follow the instructions: work a small amount at a time, - within the reach of your arm, - i.e. 4-5 sq. feet, - and clean immediately as directed. From now on, that's what I'll use.