To my big surprise this piece of 6" ducting is a pressfit and works beautifully with two screws and a bit of duct tape!
Nice, can you share a link to where it can be bought ?
Been there done that … just read the blog 
Sweet I just happen to have all that and lots of flex hose, and a serious fan that just needs cleaned and lube but I hadnt realized it would just fit perfectly or I’d already have done it.


