I'm using XCR coating resin since last year. And never had difficulties to sand it dry. If it was hardened for at least two days, dry sanding always went smooth. But I've experienced the opposite this Summer. When it was impossible to dry sand resin that was hardened for 4-5 days. It clogs sandpaper or Abranet immediately. Also noticed weaker adhesion properties of that resin, no matter that previous coat was sanded with 220 paper. I have suspicion that it has a lot to do with air humidity. But maybe there are some additives available that would help to avoid such problems ?

I've got 1kg new batch XCR resin on Monday. Tried to sand it dry after  70 hours. Result is better but still insufficient. It clogs 180 and 240 grit sanding net. Resin is glossy, but if I  hold warm finger on it for 10-15 sec, it feels a bit sticky. Working temp. 21C, humidity <50, curing temp.22-23C. It did not act in such way when working in winter/spring time. What variables else could I change ? Try to change scales ? Loosing my will to work with XCR