I'm making some test and seems like that was the problem, measuring in so little proportions is difficult and not so accurate so i think i'm just mixing about 10-20 gr+ or so to avoid this problem, the hands are very tiny. Soon i will show you pictures of the cast to show you the results
by the way, a useful tip. I've realised some small differences when the resin cures well and when isn't propperly cured. Seems like when goes wrong the final cured resin has a oily finish, and that's when the problems are coming >,<. I suggest to make a test when you are measuring small portions of resin and try to mix by volume and not weight, because is easier to go wrong this way in so small proportions.