http://en.wikipedia.org/wiki/Cyanoacrylate) There are many, many, many trade names and viscosities. I just buy the cheapest I see, usually in small tubes in a quantity at a discount store. Using a thin CA, (which is like water) and placing a few dots on the revese side of the pcb to be milled it is then glued to a piece of flat aluminum plate, tooling plate. Tooling plate is aluminum that is ground to a mirror flatness. I bought mine from ebay. CA debonds with acetone. I drill before I mill as I also use alignment pins for exact registration. By making the drills for the alignment pins part of the design process, you have perfect registration from side to side and operation to operation. See Fixtures and Tooling on my website: http://millpcbs.com/ If you want to look at something to give you how capable you can be with more technique than expensive equipment see my video: "http://www.youtube.com/watch?v=lhdqBrciQZU"]YouTube - Milling a fine trace double sided pcb Make sure to see the pictures at the end to get a size perspective.
Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
Vist my websites - http://pminmo.com & http://millpcbs.com