Bah humbug! Measure the compression on your top the next time you clamp up....two thou is 1/5th of your high-E string, its 50 microns...it's a hair man! Literally. human hair diameter
Now, Rob G may not have measured the gap accurately. However...if you think your jointing is flat and straight at better than 50 microns across 20", you're fooling yourself.
For the record, you can find a glue line on very light-colored woods no matter how tight your joint is and how white your glue is, if you look hard enough.
id have to disagree. you can see a .002". if you can see a human hair you could see light thru that gap. i may have mesured it wrong but i guess that doesnt matter. all that matters to me is that i get it jointed properly. also i understand there will always be a glue line, i was just trying to minimize the chance of having one bigger than i could help.
anyways i fixed it by starting with southpa's method and then finishing with fryovanni's.
thanks to all who have commented,
rob