I can't recall when (probably > 1 year ago), the context of the question, etc., but I asked if anyone even does shrinkage limits nowadays with so much concern about safety with mercury. I believe it was Big H who replied saying that there is now an ASTM std for doing it with wax. My guess is that the dried sample is soaked in melted wax, so it won't fall apart when put into water to measure the displaced volume.
