What is "skim coating" ?
 

I've seen references in this forum to "skim coating," "skimming," etc., and was wondering what that is? I've done a small amount of patching, sanding, and priming type of prep -- when does one do skimming? Thanks -- Rav (just a homeowner who wants to learn).

Just a very thin layer of drywall compound or plaster to level out imperfections on a wall.

Yup.to me it means covering the whole wall though.
When you skim coat a wall the whole wall is covered in a thin layer. Not an easy thing to do.

seen some roll the mud on with a paint roller then flatten with wide knife.

Thanks for all the explanations. /Rav

Page 3: http://www.lafarge-na.com/GA-214-07_English.pdf

Either spray it on and smooth trowel: http://www.youtube.com/watch?v=uwjzlSoa_Rs

Or, roller and trowel, similar to final tape coat; http://www.youtube.com/watch?v=yi-Hp3dasq8

Gary