Fiberglass prep ?

[runzwithsizorz]

I see a lot of people recommending using acetone. Would denatured alcohol work as well?

[iamandrew]

NO dont use acetone.
Ive found simple window cleaner is pretty good.
If you get traces of acetone before you put the resin down you might end up with it either not going off 100%, or ending up in a gluey consistency instead of solid

[Basstronics]

Just rough it up with some 120 grit blow the dust out and glass away.

[capnswanny]

The whole proces is pretty forgiving and you can get away with using what you've got. I've used acetone the past 20 or so years for surface prep without any problems, I find that it leaves behind very little residue.
Denatured alcohol will work fine, you're just using it to clean the surface.
Here's an excerpt from the West System (my favorite) Users Guide:
"Clean Bonding surfaces must be free of any contaminants such as grease, oil, wax or mold release. Clean contaminated surfaces with lacquer thinner, acetone or other appropriate solvent."

http://www.westsystem.com/ss/surface-preparation/

As for traces of acetone (or alcohol for that matter) let yout surface air dry before applying epoxy and you won't have any problems.