jtpr wrote:
I have a Delta DC with a 4" intake. I see pictures of shops all the
time with metal ductwork running around the shop for use with similar
units, but when I look around the local HD I don't find anything that
seems to match up with the 4" hoses.

What is it I use for this?

Most home shop folks just use plastic any more.

26 ga snap-lock duct is the only (semi-)economical metal choice...

http://www.pennstateind.com/store/economy-snaplock-pipe.html

for example. May have better luck at the HVAC supply places than box
stores locally.

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