mgso4 is a bitch in solutions. SWIM used some to dry alcohol, but couldn't filter it all out - even with good filter paper. Distill the vinegar, with a drying tube attached, so the hot vapours travel through the drying tube. that way the only product coming out of the stillhead is GAA, regardless of temperature

Are you positive this way works? Most people in here seem very reluctant to any way of dehydrating AA that does not include making acetate salt of it...

I have however decided to act the free thinking anarchist character and try to dehydrate 90% AA with the use of concentrated sulfuric acid as the dehydrating agent, and then distill, as mentioned in this thread:

Post 501244

(Bandil: "Preparation of GAA by azeotropical distillation", Chemistry Discourse).

I'll get back to you with the results today or tomorrow!