On Dec 13, 3:04*pm, Joseph Gwinn wrote:
...
Needle scalers are used for paint prep of navy ships, to remove heavy
layers of rust and paint.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=1108

Joe Gwinn

Got one, works fairly well, but not on sheetmetal. The internal air
hammer pounds the needles into the work hard enough to dent it or
chase it around.

jsw