To Susan

I have used xtra or left over tufa, over & over sometimes 50 plus hours after first mixing it even longer than 2 days later I do this by leaving the mixed material covered with water make sure it is just over the top of the tufa also make sure you flatten the tufa at least omce a day to make sure no hard lumps form.

Keep trying and experimenting you will be successful trust me I know this rock & what it does & how it reacts, as I work with it 8 hours a day for weeks on end.

making crosses boat planters etc etc.