I own a perfectly good pair of hand crimpers that are great for a carpenter’s occasional need to fuss with ductwork or downspouts. And, of course, the crimpers were safe and sound back in my shop when I needed to customize a range hood the other day. There was no metalworker on the job to bail me out, but I did have my trusty pair of needle-nose pliers in my toolbox. As shown in the drawing, I used them to put V-shaped crimps around the duct. Just a slight twist every 1/2 in. or so gave me a crimped duct that snugged right into its fitting.
Bill Pinkham, Richmond, CA