Dust Collection Ductwork

[Jim O'Dell]

I agree about using the largest pipe that you can for the major part of the ducting. That is, the largest that your collector, whether single or 2 stage will work properly with. That means not every unit will work with 6" pipe! If I had a cyclone that used larger than 6", I most likely would have used spiral. If I had known it wasn't good to use PVC where it is not visable from the shop (ie attic) I would have used spiral for at least that part. As it was, I had the PVC purchased and partially up when Bill Pentz pointed out to me that in case of a fire, it would be better to have metal in the unseeable spaces, so I had to make some major modifications to make the pipe visable from the shop floor.
I enlarged the 2 1/2" pipe for my contractor saw pick up to 6". My MM E16 bandsaw is a 100 mm port IIRC. A 4" piece of S&D PVC is a very tight fit over it, and the flex a tight fit on the PVC. I have yet to unbox the Delta 52-580 planer, but plan on following others advice and make a hood for it that , and it will have a 6" pick up, even if it makes it SCREAM. I have built a 6" pick up onto my router table and it works great.
I'm rambling...I guess I just wanted to make the point that not every dust collection machine out there is going to perform better with 6" pipe. Jim.

[Jim Eller]

Steve A.,

Hope I don't steal your thread. I am in the same boat, trying to figure out what to with duct work for my Oneida 3HP Gorilla.

I got the "free" design from Oneida. It all looked great until I got to the page with the $$$$'s on it. The quote was $1845.89 for snap lock pipe in a 25x30 work area. For that price I can put another Gorilla at the other end and use flex hose.

Anyway, the questions are, what are the sources for large diameter snap lock pipe and PVC and how do you transition between snap lock and PVC?

Thanks,
Jim

[Jim Becker]

The set-up works great, my only complaint is there is no easy way to tell if the barrel is getting full other than to pull the lid and look.

Sure there is...put a window in the top of the bin using 1/4" Lexan, caulk (to seal it) and screws. I've had one in mine for years. Of course, you still have to actually REMEMBER to look.

how do you transition between snap lock and PVC?

Easiest way is to come out of the cyclone with 7" or 8" metal to your first branch and use metal through that point. At the branch drop to 6" and then make a little roll of metal to fit inside of PVC to create your own crimping area. Buy or borrow a crimper and do what you need to do to adapt to the metal duct. (The crimp needs to be facing the cyclone) Alternatively to crimping, make the same roll of metal and insert in the 6" PVC. Fasten in place with pop rivets or screws. Then, use a rubber clamping pipe splice from the plumbing section of the 'borg to mate to the metal duct.

[Steve Sawyer]

I used two 45s to make a long right angle sweep...cheaper than the long-radius right angle.

I've heard many do the same thing. Hate to give up that smooth curve, but yeah, those darn elbows cost a fortune...

[Brad Peterson]

Steve A.,

Don't know the specifics of your application and I can't respond to your question re: Onieda pipe, but... I used HVAC snaplock for my cyclone piping. 7 inch main, 6 inch and 5 inch drops, home made blast gates, I had the local HVAC shop build the wyes I needed. I think I spend just under $200 on all the pipe and custom fittings, that doesn't include the coffee cans I used in making the blast gates. The set-up works great, my only complaint is there is no easy way to tell if the barrel is getting full other than to pull the lid and look.

Also, a 4" PVC waist line??? That is one skinny dude.

Any more details? I am on the blast gates myself....

[Brent Grooms]

Do yourself a favor and look around locally.... I was given a tip on a blower supply company where I had a 7x7x7 45deg lateral (20ga) made for less than $45 and can buy spiral 6in for about $2/ft.

Often times is asking for the right product or explaining what you need accurately.

[Steven Wilson]

I'm reading the thread because I'm planning a run of 4" ductwork and found the negative reply by Steve Wilson regarding PVC ducting to be pointless and annoying.

Well Larry I'm glad you found my comments annoying. I try to make them annoying to folks' like yourself who are totally clueless.

I guess some people are duct snobs. It is not a down grade. It is smooth walled and is much more durable. It won't dent easy even though it is light and connections are simple and air tight with no special tools needed.

So Keith it's your expert opinion that Steve should run 4" PVC from his tools to the intake of his cyclone. Never mind that at best he'll get 300CFM from his machines and that his whole system will be neutured by following your asinine advice. Those with a brain choose their duct sizes to correspond with the CFM needs of their tools and the duct run they need to get from their collector to the tool. Rarely is 4" PVC (or metal) the answer. With PVC you're choices are 10", 8", 6", and 4" with 8" and 6" being the most usefull. Due to the lack of intermediate sizes you may run into velocity issues if you choose PVC, but of course you can design for that. But of course Keith Ouellete is the man and he says that 4" is all you need for whatever you want to do, anyone else is a duct snob. Thanks for you useless comments Keith and please keep displaying your ignorance. PVC isn't a problem, although it isn't as flexable as metal for designing or building your duct work, but suggesting to run 4" for everything is stupid.

[Steven Wilson]

Steve A.,
I got the "free" design from Oneida. It all looked great until I got to the page with the $$$$'s on it. The quote was $1845.89 for snap lock pipe in a 25x30 work area. For that price I can put another Gorilla at the other end and use flex hose.

Jim, Oneida is pretty good at sizing duct work based on your shop layout diagram. However, they rarely recommend changes to your shop layout that could result in much less expensive duct work. If you rework your shop layout a bit you might find that you can save a significant amount of money in your duct work. From the initial design Oneida did for me I was able to rework some items and ended up reducing my duct work costs by %40. One way I was able to save was staking up some wye's to make multi-drops (i.e. a 6" branch to a 6x5x5 then 5x5x5 wye's to get three 5" gates).

[Will Blick]

I like this concept of two 45's in lieu of a 90 deg elbow. I also like the fact it would be cheaper, but yet, when I checked the McMasters site, the cost of a 6" 45 deg. elbow was the same cost as a 6" 90 deg. elbow? What am I missing here?

Two other questions for PVC users...

1) I assume everyone is using Sched. 40?

2) I assume its best to use drain pipe, not sewer pipe?

TYIA

[Jim O'Dell]

I like this concept of two 45's in lieu of a 90 deg elbow. I also like the fact it would be cheaper, but yet, when I checked the McMasters site, the cost of a 6" 45 deg. elbow was the same cost as a 6" 90 deg. elbow? What am I missing here?

Two other questions for PVC users...

1) I assume everyone is using Sched. 40?

2) I assume its best to use drain pipe, not sewer pipe?

TYIA

Will, no the sewer and drain, ATSM 2729 thin wall gravity fed, is what to use. It doesn't have to hold pressure, and the PVC is plenty stout enough to handle the suction. S&D pipe is 1/10" thick and much lighter than schedule 40. Jim.

[Chris McKimson]

Will,

I'm not a PVC "user", but I believe that most who are using PVC for duct work are looking for sewer & drain (or ASTM 2729). The schedule 40 stuff is heavier and more expensive without any additional benefit.

Chris

[Will Blick]

Makes perfect sense.... why make it heavier than it needs to be.....

[Josiah Bartlett]

I run dust collection on my 22-580 planer. I have it mounted on a cart that is basically a plywood cube with casters on the bottom. I have a short length of 4" dust collection hose mounted from the hood to a 4" port on the box, then a 6" port on the other side of the box off to the dust collector. Since the Delta dust collection adaptor rides above the wood exiting the planer, anything bigger would rub the wood. I've never clogged it, it works great. I've even just run it for a short run without the 6" side connected and most of the chips just ended up in the box.

[Steve Sawyer]

Well Larry I'm glad you found my comments annoying. I try to make them annoying to folks' like yourself who are totally clueless...at best he'll get 300CFM from his machines and that his whole system will be neutured by following your asinine advice. Those with a brain choose their duct sizes to correspond with the CFM needs of their tools...Thanks for you useless comments Keith and please keep displaying your ignorance...but suggesting to run 4" for everything is stupid.

Steven - it seems to me that your points could be made without being rude. There are many who have systems that function adequately using 4" ducting. Note that I said "adequately" not "optimally". We're all here to share our experiences and knowledge to help one another make intelligent purchase and design decisions, most of which involve a trade-off of some kind between time, money, space and performance.

You have valid points to make that can help others make the right choice for their situation, but you devalue your own advice by being disrespectful of the advice and experience shared by others. They're not stupid, asinine, clueless or brainless - they simply have made different choices than you have, and as a result have different experiences to share.

[keith ouellette]

When i was inquiring about duct size i was warned away from using the larger pipe because of loosing pressure (or something to that effect, I can't remember the exact words). My system is a 1200 cfm and it pulls everything quite well. Is there any truth to what I was told? (I might have to get some 6in pvc)