Next,

some foam pipe insulation is wrapped around the bottom of the tube and held in place with duct tape.

then a larger tube is made for the smaller one to fit into, but this tube is two inches shorter.
babystarbud Reviewed by babystarbud on . Home made carbon filter A variation of the one in the FAQ;s This is a large filter suitable for 6-8 inch ducting. Ingredients: wire mesh tie clips large Rating: 5