7 inch dust collection ducting?

  • Advertise with us

« back to Safety in the Woodworking Shop forum

Forum topic by Jesse posted 12-16-2013 05:04 PM 3918 views 0 times favorited 8 replies Add to Favorites Watch
View Jesse's profile


58 posts in 1619 days

12-16-2013 05:04 PM

Topic tags/keywords: dust collector grizzly

I recently bought a Grizzly 3HP double canister dust collector for my new wood shop. It turns out that the inlet is 7 inches and I am having a heck of a time finding any piping and fittings that will work with this size of an inlet. I think PVC only comes in 6 or 8 inch and I’m not sure about easily obtained metal duct work? Also, I need to have elbows, straights, and Y type fittings. Of course a lot of my machines have 4 inch ports so I need to be able to reduce at the machine, not sure if metal ducting has options for this?

I found a few places online that want what seem to me to be crazy amounts of money for the fittings so I am wondering what you all use? I really don’t want to take it down to 6 inch unless I have to. I want to do it right (this is my huge dream shop I’m building here) but I don’t want to spend as much on 40 foot of pipe as I did on the machine itself. Any help is appreciated, thanks in advance!

8 replies so far

View Fred Hargis's profile

Fred Hargis

4980 posts in 2487 days

#1 posted 12-16-2013 05:29 PM

Deleted, it was a double post.

-- Our village hasn't lost it's idiot, he was elected to congress.

View Fred Hargis's profile

Fred Hargis

4980 posts in 2487 days

#2 posted 12-16-2013 05:37 PM

Mine has a 7” inlet, and Oneida suggested I run 7” for at least the first 5-6 feet before transitioning to 6”. So I used 7” HVAC snaplock and 2-7” HVAC el’s to run the duct up to the ceiling, then transitioned to 6” PVC. If you choose snap lock, be sure to get the heaviest gauge you can get; a lot of guys have collapsed the 30 gauge stuff. The transition to PVC is fairly easy to do, though it’s not particularly attractive. A 7×6 HVAC transition (reducer/enlarger) will do it, as for the appearance I’m a function over form guy (really don’t care what it looks like). Here’s what I did to my drum sander to get a 6” port on it. Like I said I function over form, and this works really well.

-- Our village hasn't lost it's idiot, he was elected to congress.

View shipwright's profile


7979 posts in 2791 days

#3 posted 12-16-2013 06:40 PM

This is the second time in a couple of days that I have posted this reference. It is a good solution to the high cost of fittings.

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees.

View descolada's profile


54 posts in 1791 days

#4 posted 12-16-2013 10:56 PM

I had the same problem looking for 7” duct in my system recently. If you want to go the sheet metal route (as i did) penn state has pretty reasonably priced. I bought my system using their economy line and it it was a bit of a pain trying to connect everything using duct tape, but worked great once installed. You can find it here:

When I went to expand the system I used their economy pieces except i switched in the premium drawband connectors. At 7” they are $20 each instead of $10, but much beefier and easier to install.

View Jim Finn's profile

Jim Finn

2656 posts in 2915 days

#5 posted 12-17-2013 03:55 AM

I put in a six inch system all of 24 gage steel. I am a retired sheet metal worker so I made the wyes myself and bought the ells. You could get a sheet metal shop to make a taper for you to fit PVC and use PVC from there to the equipment. It would be one rather expensive fitting but only one.

-- Website is No PHD just a DD214 and a GED

View copcarcollector's profile


256 posts in 2111 days

#6 posted 12-17-2013 05:32 AM

I have that exact dust collector. I ran a small amount of 7 inch metal pipe to turn the corner and go up wall, then used an adapter down to 6 inches for all of the main runs and drops.

View Jesse's profile


58 posts in 1619 days

#7 posted 12-17-2013 09:14 PM

Having the exact same dust collector, how do you like it so far? I haven’t used mine yet

View Holbs's profile


1863 posts in 2023 days

#8 posted 03-04-2014 02:37 AM

i’m in the process of doing all this myself. gots a blog going with building a Thien Baffle (still in progress).
Everyone that has a grizzly 3HP dual canister says they have 7” inlet. While mine is 6”.
I was lucky.. I have a friend at a HVAC distribution supply house. I get my 6” why’s for $3 and snap lock 5’ for $7 (all 26 gauge).
Was about to fiddle with the wye’s… then I found out they are facing the wrong direction. Unsure what to do about it! Grr…

-- The Carpenter Bee is derived from the Ancient Greek word wood-cutter

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics