Like many folks in pottery, my hands were chapped and cracked while my fingernails were constantly tearing.
I talked to my dermatologist about this. He made two very effective recommendations that I want to pass on.
1. Curel hand cream.. This stuff is unlike anything else I have tried. When you put it on it has the same oily feel of most hand creams. After a few minutes it is absorbed into your skin with no sense of oiliness left. I put a small dab on before I go into studio then again when I wash up. It has made a huge difference in my skin. You can get the stuff for about $12.00 for 16 oz at Walmart or Walgreens
2. Daily dose of Biotin. I take 1000mg. It takes about 4 month to see the difference,... for your fingernails to grow out. At that point, the difference is dramatic. No more torn or broken fingernails. You can get this stuff cheap on Amazon or eBay.