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

Pipe couplings have lots of fit flexibility and ironclad gripping because of their stainless-steel clamps. This mitersaw port and hose, both with about a 1 3⁄4" outside diameter, were initially a loose fit in the 1 1⁄2×1 1⁄2" coupling.


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.

Rubber adapters stretch to grip tightly. These two adapters (nos. 192407 and 192408,, have respective diameters of 19⁄32×1 1⁄8" and 11 1⁄16×1 1⁄8".

• Buy a flexible rubber pipe coupling. You’ll find these fittings online and in hardware-store plumbing departments, sized for 34 " 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 14 " 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 112 ×112 " coupling has an i.d. of 1.94", the approximate o.d. of 112 " 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 114 " to 112 " diameter. (To fit the hose shown, we cut off the hose’s factory-installed port.) 

A pool-hose connector gets the job done. When using a connector that goes inside the hose, cut off any excess at either end to lessen air resistance. Find the connector at swimming-pool suppliers or

• 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

Go bigger with a few layers of tape. Most any tape will do; we enlarged this biscuit joiner’s port with masking tape, applying enough for a good friction fit.

•  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.

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