Ran across the publication Epoxyworks - with numerous articles on using West Systems epoxy. You can sign up for their "free" publication at http://www.epoxyworks.com
While the web site is 2 issues behind.. The Fall 2013 issue #37 on page 5 has an interesting article on West Systems 876 Release Fabric which allows you to work the epoxy while it is curing.
They also describe how to remove blush and it seems that the West Systems 207 Special Clear Hardner - doesn't have blush at all.
Jay
