Make a good connection even when it's a bad fit

I'm doing my level best to corral airborne dust at its source, but hooking my portable and benchtop tools to a shop vacuum has proven a challenge. Tool dust-port diameters vary—some metric and some imperial—and don't mate with my vacuum hoses. Any suggestions for making connections between ill-fitting ports and hoses?
—Randy Welch, Royal Oak, Mich.

Before you break out duct tape to make the connection (at least temporarily), Randy, try one or more of the following:

* Check the tool manufacturer's website. You might find the adapter you need—one not originally supplied with the tool or one you simply lost over time.

* Get a second-party rubber adapter. Woodworking retailers sell various hard-plastic adapters, but we prefer flexible rubber ones, photo below, for their greater adaptability and no-clamp grip.

* Buy a flexible rubber pipe coupling. You'll find these fittings online and in hardware-store plumbing departments, sized for ³⁄₄ " to 12" pipe. Some couplings, like the one above, bridge ports and hoses of similar outside diameters (o.d.); others adapt diameters that differ by ¹⁄₄ " or more. When choosing a rubber pipe coupling, remember they are sized by the inside diameter (i.d.) of the pipe they fit over. For example, a 1¹⁄₂ ×1¹⁄₂ " coupling has an i.d. of 1.94", the approximate o.d. of 1¹⁄₂ " plastic pipe.

* Look outside of woodworking and plumbing channels for fittings. A pool-hose connector, photo below, though made of a plastic that's only slightly flexible, has a narrow taper, and ribs that solidly grip inside openings from 1¹⁄₄ " to 1¹⁄₂ " diameter. (To fit the hose shown, we cut off the hose's factory-installed port.)

* Use tape to increase a diameter. Though we don't recommend using tape to bridge a connection, it does provide a good means of slightly increasing the outside diameter of a tool port, as shown, photo below.

*  When all else fails, go ape on the connection. If you're in a hurry and absolutely have to tape over the connection, get Gorilla Tape—it's tougher and stickier than run-of-the-mill duct tape.