This is not a sure-fire solution to get a wonderful section of nail that 
stays on slide, but it seems to help sometimes.  If the nail is really hard 
we try to face into the block and place block face down in NAIR (stuff to 
remove hair with found at most pharmacies or Kmart, Walmart) and leave it sit 
for a couple of minutes. This seems to soften some of the nails.  While 
waiting we put liquid gelatin solution on plus slides and let them air dry.  
Wipe off the NAIR and try to get a section.  I have also heard of soaking the 
blocks in glycerin (also softens the nail) after facing into the block.  Good 
luck.

Jennifer Macias, HT(ASCP)
Forum Health-Western Reserve Care System
Youngstown, Ohio