Bob S. wrote:

I have a 5000W emergency power generator I got a year ago that has
been very handy in here in the northeast. But like most, the damn
thing is loud and you can't hear yourself think if you're within 25
feet of it. Decided it's time to tame the beast a bit so I picked up
a 2' section of 6" duct pipe, two 6" to 4" reducers, a roll of 1/4"
sq hardware cloth and a small roll of unfaced fiberglass insulation
(pink stuff).

ISTR discussions on this at either or both of these NGs:
rec.crafts.metalworking
sci.engr.joining.welding

HTH

-- Mark