Greg,
You can quit Harvard and set up for full time iron restoration and cleaning...doing what you love to do best. No more writing grants, politics, etc.
If you want to see a great article on blasting and blasting media it appeared in a recent Porsche Club publication. The writer was very experienced in blasting aluminum and magnesium and made some good points on why to use which medium. I don't have the mag but could get the number of the issue or, possibly, a copy of the article. The author even talked about cleaning with one media and then using another for finish up with so it would leave the surface grain "closed" so that no dirt would get into the surface of the casting so it would stay cleaner longer. He talks about using new glass beads for some blasting and used glass beads for other blasting. The result is different and new beads get used (broken, sharp particles) fast. I think the new beads were specified to finish a casting as that would tend to peen the surface and close up any pores. He even had a table for different media and when to use what and at what pressures.
Steve