On Thursday, March 25, 2010 at 10:30:47 AM UTC-7, Robert Montgomery wrote:
What's a fairly quiet, lightweight upholstery electric staple gun that's
powerful enough to penetrate pine?

What kind of wood? Pine includes 'southern yellow pine' which is
somewhere between white oak and red oak in toughness.
Pine also comes with knots (some of which are very hard).

I tried the Arrow electric lithium-ion battery cordless electric, but
it's very loud and the staples didn't penetrate the wood all the way.

What length of staples? If these are 1/2" long, and penetrated 3/8",
would you consider using shorter staples?

Percussion is the driving principle in staplers, some noise is
intrinsic to the method.