dust collection ducts

[john mclane]

I just got the Jet 1100 C model with the Canister filter this weekend. The 2 collection ports are only 4" . I have a tablesaw, band saw, router, drill press and would like to get jointer next year. Both myselfs and sons are now using the shop on a pretty regular basis. I started looking at the 6" duct system but am having trouble finding the right connections and Y joints. I did find the metal pipes, connectors and joints in the Grizzley catalog but it looks like a 6" runs with 4" side runs to some of the machinery (TS and BS) is going to cost another additional $3-400.

Can I join a 6" main run to a 4" pail "cyclone" separator and 4" ports on the dust collector without problems?

Should I just stay with 4" mainlines and side lines?

Is there a good source of plastic PVC schedule 2 with appropriate joints and connectors.

Could I save some money and use the 4 or 6" flexible plastic ducts?

I included a rough diagram from visio. The room overall is about 14X28' stone walled cellar (6.5' ceilings). The heavy black line is the main run, the green 4" sidelines, and the red, 21/2" sidelines for hand tools.

[JayStPeter]

Pull off the 4" y-connector on the front and reveal a single 6" port.

[Jim Becker]

The trash can thingie likely isn't going to be happy with the increased airflow that the 6" duct is going to add to your system...it will likely remain "clean" and the chips will flow all the way to the DC.

[Ken Baker]

Go to Bill Pentz website - as far as I'm concerned he is the God of Dust Collection. You can spend forever reading it but bascially your goal is as straight of a line as you can between the DC and the unit. Make your turns as gradual as you can - i.e two 45s and a staright piece in the middle instead of a 90, eliminate resistance as much as possible. Flexible duct is real easy to install - but it adds resistance. Use it sparingly. He is a big advocate of 6" PVC sewer pipe - interior is very smooth.

I installed a Clear Vue Cyclone - 5HP motor, 14" impeller. From it I'm running 6" PVC pipe with gradual turns, I use blast gates as close to the main line as I can to not pressurize lines when they are not needed. My tablesaw has 6" PVC running to the bottom - with only a few feet of 6" flex and then into a 6" port on teh back - not the standard 4" port. You have to make your ports as big as possible. I took the unused 4" port and mounted it on top of my Biesemeyer Overhead guard in place of the 2 1/2 port they supply. I have 6" PVC coming overhead and then it changes to 6" flex to come down to the guard, and at the last connection I transition from the 6" Flex to 4".

You can get the 6" and 4" PCV Wyes and such at a landscaping supply. Your local Borg will have some HVAC metal fittings you can use to make certian connections - I.e. the 6" dust port on the back. And lastly you have to be a liitle creative - 6" Flex hose doesn't fit over 6" PVC - but take a 6" HVAC metal flexible elbow and it fits just fine between the two.

[Bob Dodge]

John,

Do you feel you need a permanent duct network? Are your other machines placed close to the dc? Unless you're using sanding-drums on your drill-press, do you really need dc at that machine?

Your main concern is your tablesaw at this point. I'm presuming you have a 10" table-saw. Ideally, 2-point collection will work best at that machine. An over-arm blade cover, will significantly reduce the amount of airborne dust from "above the kerf", especially if you work with sheet-goods like MDF, Malamine.

If your dc is close to the saw, you can connect one 4" pipe to your base, and the other 4" pipe to an overarm blade-cover. Small commercial units will have hood porting in the 2"-3" range. When you do a double-hook-up like that, using two 4" hoses, the static-pressure in both branches will "auto-balance". You'll pull more air through the base's 4" branch, because there will be less resistance. With your dc next to that saw, and with waste flowing downward, you don't have to concern yourself with transport velocities. If the dc is permantly located, and away from the saw, that's a different story.

The manner in which you run your pipe will also come into play. With a ceiling-hung main, you'll want to ensure you have adequate transport velocity in your drops as well as the main. A certain 'balance" is required. You don't want unnecessarily high velocity. 3,500 FPM is fine for the horizontal runs, and 4,000 FPM in the verticals.

"How much 6" pipe can I run?" Well, that depends on your network. If you have a single 4" drop at the end of a 6" main, you probably won't have enough suction to feed the main properly. That 6" main, would need at least 685 CFM in order to flow at 3,500 FPM. With an 11" impeller, your dc won't get there. To give you an example, a 2 HP Jet DC-1200 with twin 1-micron filters and a 12" impeller, flows only 525 CFM when connected to 20 feet of 6" pipe, then a reduction to 4 feet of 4" flex. Knowing that, you can plan your ceiling runs accordingly. In that situation, you could use 6" pipe from the dc, until you reach the ceiling-turn, then reduce to a 5" main.

Personally, if I were doing it, I'd place the dc close to the saw and jointer, then use a short floor-level run to your saw, with a 6" pipe, splitting to two 4" pipes at the saw. (base, and blade-cover). The downward flow into the 6" main would be non-critical, and as long as the twin 4" ducts feed a total of at least 685 CFM to the 6" main, that portion of your network will be fine. Your dc will flow it's maximum capacity.

Off that run, you can come off the 6" main with a 6" take-off, rising to your ceiling, and a 6" elbow for that turn towards your other machines. At that point, you can reduce to a 5" main, and that will handle the airflow from the 4" drops at your smaller-requirement machines.

As far as your jointer goes, if it's a 6" jointer, I'd go with a 5" drop, and reduce only at the hood if need be. If that machine can be served by a take-off from the saw's floor-level branch, all the better.

Good luck,

Bob

[Bob Dodge]

I should also mention that it would be a good idea to remove that double 4" wye adapter from your blower's 6" intake. Use that fitting at your saw's split if you want. You should always have at least a few feet of full-diameter straight-pipe at the dc's inlet. This will reduce the inlet turbulence that your impeller has to deal with. A nice laminar flow into the impeller, means your fan-wheel will get a better bite at the incoming air. 2 feet is not bad, but 3'-4' would be better.

[Lou Ferrarini]

The Blue Borg in my area carries 6" PVC and all the fittings. I have the same DC as you and am running a 4" main right now. After I expand my shop next year I am going to upgrade to the 6" pipe. One thing I did which you may want to consider, instead of gluing the pipe together, I used that foil metal duct tape to seal the joints. I makes a good seal and comes off easily if you need to rearrange your pipes.

[mike wise]

Most of what I have read suggests that you should use metal duct. The plastic duct increases the risk of static electricity in the system. Dust and static electricity can cause for one heck of an explosion. I suggest you read the information on Oniedia's web site with regard to sizing the duct and the type of duct.
Good luck.
Mike

[Al Willits]

Not having a clue, I was just wondering, are you going to be running more than one tool at a time?
If not, maybe you don't have much of a problem and should just see what happens?
If one or two, maybe see how it responds to two going at once.

Might be 3-400 bucks ya don't need to spend?

Al