What is Crawling?

Here's a description and photo of the finish defect called "crawling" (caused by surface contamination or incorrect prep).May 30, 2011

Could someone please give me a description of crawling?

Forum Responses
(Finishing Forum)
From contributor R:
Just a few descriptions related to coatings:
A) What a finish does just prior to it becoming a full blown run.
B) A coating that begins to bridge. In other words, if you try to finish an edge that hasn't been eased, the coating will start to crawl away from the 90* edge.
C) How the finisher enters the spray booth in the morning after a night of pounding a few too many.
D) I'm sure the term could be applied to some glue techniques as well.

From Paul Snyder, forum technical advisor:
Crawling is when the finish pulls away from an area that has low surface tension. Often caused by silicone oil or a furniture polish that contains silicone, though other products can also cause the contamination problem. Crawling is a larger version of fisheye.

Click here for higher quality, full size image

From contributor M:
We ran into this exact problem on a door we did last weekend. My guys did not follow procedure for cleaning the wood before applying the stain and finish. We are redoing it this week in the shop. I hate crawling, but it is avoidable.