iron furnace charcoal burners

Searching for charcoal burner who worked for various iron furnaces from 1790-1850. Trying to trace backward from 1835. Have read ledgers and account books at Pa. Hist. Soc., Pa. Archives, county historical societies, Hagley and Winterhur. Has anyone had luck finding lists of workers names? I have read many books and realize these workers were migrants, were isolated from community for greater part of the year, didn't own land or get in county tax lists. Very hard to find and would appreciate any help or advice.

Ann