I have never heard the idiom, supposing it is one, but the writer is describing an on-going struggle to keep one step ahead of failure. Imagine someone hanging from a cliff; they do not have a firm handgrip, but are hanging by their fingernails, and could fall at any moment.

A more familiar expression to me is:

Quote:

by the skin of one's teeth by a very narrow margin; barely : I only got away by the skin of my teeth. [ORIGIN: from a misquotation of Job 19:20: “I am escaped with the skin of my teeth” (i.e., and nothing else). Current use reflects a different sense.]



EDIT: Or, given the context:

I was just scraping by
I was just getting by
I was barely managing
I was circling the drain e.t.c.

So, to answer your question, the writer means that he or she was able "to stay in the trade", but only just.

Last edited by Hydra; 08/24/2006 3:54 AM.