PortMatch
CONNECTION

Connect a Router table fence port to a 4 in dust-collector hose

How to join a Router table fence port to a 4 in dust-collector hose, and what stops it leaking dust.

Not compatible

Not compatible without stepping down. A 4 in dust-collector hose is far larger than the Router table fence port, so it needs a 2-1/2 in to 4 in step reducer.

END B101.6 mm4 in dust-collector hose (4-1/4 port in OD, 4 in ID)
END A68.3 mmRouter table fence port (2-11/16 in OD, 2-1/2 in ID)

Rings drawn to scale from the measured diameters in the table below.

The two ends

End ARouter table fence port (2-11/16 in OD, 2-1/2 in ID)
End B4 in dust-collector hose (4-1/4 port in OD, 4 in ID)
Fit typehose cuff into female socket
Reducer needed2-1/2 in to 4 in step reducer

Shop notes

The port socket is about 64 mm and the hose tip about 102 mm, a gap of 38 mm, so the hose tip simply swallows the port socket with no contact. A 2-1/2 in to 4 in step reducer is needed, and even reduced the airflow is mismatched between the Router table fence port and the 4 in dust-collector hose.

Wrapping tape to close a 38 mm gap never seals cleanly and chokes the airflow further. Step the sizes properly, or pair each end with a fitting closer to its own size.