MM --- Not sure about 'Tufa, but it's an everyday occurance with my low water cement mixes. I first dry mix all my ingredients for at least 15 minutes, then add 50% of the total water volume (with all my wet admixes in it) by pouring it in slowly. I then let it run for a good 10 minutes before I start adding the final balance of water. It's during that first stage that the balls form. Once it's been running for about 10 minutes they become slightly larger and I start slowly adding the balance of the water using a fine mist nozzle in short spurts. Pretty quickly the golf balls turn into potatoes, then with a few more spritzes, it all becomes the nice big chunk of dough that is my desired working consistency. In fact, I gauge my mix status by watching for that exact transformation. Total wet-mixing time usually runs around 15-20 minutes.

PS...Most people way UNDER-mix their formulas.

Anyone have any 'Tufa observations or techniques to share?

I get the balls in the middle of mixing tufa in my electric mixer. Just like you they get bigger and then absorbed. I also go for dough like consistency, with the blade cutting through and leaving a mark as it goes 'round.

I have just made a slab of harder concrete, 12" x 24", 3" thick. It goes on my workshop table and I use it to shape the edges of the bowls. Upend the bowl and push back and forth keeping a wet slurry the whole time. It's much easier on the back and requires much less effort. Of course, I've put bowls that were too green on the slab and broken them. Just when you can barely make a mark with a fingernail - that's about the perfect time.

And now...off to the studio/workshop (oh, that sounds better than it really is!)

Mercedes

Thanks, I'll try that and see what happens!

MM