MIMF

Hi, it was time to extend a run of the Sch. 30 dust collection duct, and the fitting of blast gates, wyes, and connectors to the Sch. 30 pipe has always been an issue. I've found an effective solution.

At JoAnn Fabrics or other craft store, you can buy a roll of 2mm foam for $7; ask for "Darice Foam Roll 36"X60"-Black". Cut a strip that is 1-2" wide, and that is long enough to go around the male fitting. and then tape it to form a ring (left in pic). Place the ring part-way into the Sch. 30 pipe (center in pic), and then insert the fitting until it bottoms out. Simple, and effectively snug, and cheap. A wrap of sealing tape might be needed on the joint, but probably not if the ring is carefully sized.

Oh, and you can use the rest of the foam roll on your benchtop, to protect an instrument or provide a non-glare, soft work surface

Good stuff Bob.
I've resorted to a wide variety of unsavory tricks to get this to work (most involving copious amounts of duct tape).
I'll have to try this next time I add a machine.

Also car tyre inner tubes are a good source for wide "rubber bands" as you can cut them to any width....they'll also work on square ducting and good for bridging slightly out of line ducting.

That foam is what I use to line my radius dish when bracing guitar tops; just enough "give" that it won't allow a stray piece of dirt to put a dent in a soft spruce or cedar top, yet stiff enough to maintain the intended radius.

Nice use of it as a gasket, here! Your seal would be much better if you cut the lengthwise slit on the diagonal, though.

That's a good idea to cut the seam on a diagonal.

Another thing that I like about this, is that it's easy to take the joints & sections apart if that becomes necessary, and there's no gooey mess from adhesives of tapes.