I’m a DIYS who will be using about 60 pounds of USG Diamond Veneer (DV) finish as the finish coat over a kiva fireplace I am building. The base coat is Structo-lite over metal tubing and lath (Adobelite product). I’ve purchased some pigment from DirectColors and I have created several 6”x6” samples chips—settling on one mixed at a 6 to 1 ratio (DV to color). During the sampling process I learned this stuff sets up fast. I will have to mix several batches and, perhaps do the job in more than one session (because I’m old and slow). How would you add the pigment to the DV to assure consistency throughout the process? Should I add it all at once according to ratio and then just mix batches with water as I go? Sounds scary. Any tips? Thanks.