Dust collection duct question

[Dan Larson]

I need to transition from either 3" or 4" snap-lock pipe to 50 mm flex hose... I haven't been able to find the right reducer or combination of reducers to do this. The closest I've found is from Felder... they sell a 80 to 50 mm reducer. Unfortunately 80 mm is 3.15"... which is probably not going to be close enough. Any suggestions?

Dan

[Roy Wall]

Dan -

I've used a local sheet metal fabricator (ductwork, HVAC supply, etc) to have a few specialty sizes made. Price was equal or better than Oneida with good 24 guage material... 5" to 100 mm and a 6" to 120mm as I recall.

[Eric Wong]

If you have a good deal of patience, you might be able to fabricate something yourself. Check out this link to Bill Pentz's site:
http://billpentz.com/woodworking/cyclone/Ducting.cfm#Transitions

This instructions are for making a square to round transition, but you might be able to kit bash this into a round to round.

[Mike Langford]

Do you own a lathe or know someone who does?

Maybe you could find a PVC reducer that has dimensions that are close to what you need and then turn it down to size.....:confused:

[Dan Larson]

Dan -

I've used a local sheet metal fabricator (ductwork, HVAC supply, etc) to have a few specialty sizes made. Price was equal or better than Oneida with good 24 guage material... 5" to 100 mm and a 6" to 120mm as I recall.
Thanks Roy, I think this is probably the way to go. I'll have to go crack open the yellow pages & call around.

Dan

[Philip Glover]

Dan,
Contact Air Handling Systems.
Here's the link http://www.airhand.com/default.asp

Cheers,
Phil

[Jamie Buxton]

Y'know the crimps in the male end of the usual HVAC duct? Their primary purpose is to reduce the diameter of the duct so that one section of duct fits inside the other. You can make crimps in the end of any metal duct, and thereby change its diameter. In fact, that's how I connected 6" vinyl flex to my metal duct: crimp the metal. You can buy a crimping tool wherever you buy HVAC duct. They look kinda like big pliers.

[Lee Schierer]

What I've done with pvc to adapt to flexible duct is to take a short sction of pvc and put it in a joint connection type fitting as a short bushing. Then take another piece of pvc pipe about 5 inches long. Stand that short piece up on end and cut through one wall with the bandsaw. Then overlap the pipe where it is cut and squeeze it down in diamater so it fits inside the ID of the bushing piece. Mark where the overlap comes to and slice off that section of the pipe wall. Mate the two edges together and apply pvc cement to bond the two edges together. Now out have a piece of pipe that has an OD that is the size of the ID of the flex pipe. You could do several iterations of this to get to the size you need.

You might waste peice or two until you get he hang of how much wall (circumference) to remove, but the process works well.

[Eric Wong]

Lee, I like your method! I've got some tool hoods to make, I'm going to give it a try.

[Jeff Miller]

The flex hose will fit inside of a PVC female fitting (coupler,street L, elbow,etc), anyplace 4" PVC pipe goes in to make a connection.:cool:


http://i44.photobucket.com/albums/f32/woodfarmer/shop/shop048.jpg

[Eric Wong]

Sweet, thanks for the pic! Between using 6" female PVC connectors, and cutting a few custom ones, I'm all set!