# DC questions



## UpstateNYdude (Dec 20, 2012)

So I recently purchased a 2HP Grizzly DC its rated at right around 1700CFM and has a 6inch main inlet, after scouting around I've realized that keeping it as 6inch runs will give me the best suctions I've already started building a tophat thien baffle collector for it but my questions are as follows…

1) Should I use PVC or Metal ducting I don't have very long runs planned maybe a straight pipe with some Y's out to the machines then flexible hose from there so maybe 20' in length.

2) If PVC do you need to use the double insulated as it is a type a vacuum and the single walled foam stuff isn't rated for any type of pressure.

3) Also if using PVC do I seriously need to ground it out as I can't find a definitive answer although I'm think I will just to be safe rather then sorry.

4) Where can I get good but cheap 6" flexible dust collector hosing

Thank you in advance


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## wapakfred (Jul 29, 2011)

Last question first: 6" hose is easy to find, but may not fit your definition of "cheap". Grizzly carries it, as does Woodworker's Supply and several other vendors. I bought mine at WWS and it's very good hose. As for metal versus PVC, I'd price the parts you need (with fittings) and get whichever is cheapest. My system is 6" PVC (except for a short length of 7" metal) and work very well. With PVC you do not have the wide range of size that metal offers. On the other hand, with metal it can be hard (or expensive) to find true wyes. If you wind up with snap lock for the straight sections, you'll have to seal the seams. I think PVC is more common due to costs, but it pays to check. If you do go with PVC, you want the Soil and Drain, which is also called "thinwall", DWV, and a soil pipe. To avoid confusion (especially with Skippy Stockboy at the box store) look for the markings "ASTM 2729". That has 3000# crush, so you won't suck it flat. BTW, if you go with snaplock stay away from the 30 gauge stuff, you can suck it flat. Lastly, grounding PVC is an urban myth that will not die. Save yourself some grief and money; if you go PVC skip the grounding. Should you choose to ground it, you will be sorry…but probably no safer.


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## PurpLev (May 30, 2008)

metal is preferred because it has less friction (air and debris), but if PVC is only available to you or more affordable, it will work just fine.


no need for double wall. the thinner walled pipes will work just fine - you are not creating a vacuum here, just passing a lot of air through them (think of straw - as thin as it's walls are - as long as it's open on both sides it will not collapse regardless of how much air you blow/suck through it)


no you do not NEED to ground PVC, but you CAN if you encounter static shocks often when working near it.. for starters I would stay away from grounding and adding interference to the airflow.


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## UpstateNYdude (Dec 20, 2012)

Alright so I realize with Metal I'll have to seal the part where it locks together on the pipe but what do you use to seal the connections or PVC or Metal fittings just that 1 time stick tape or will regular duct tape work just as good I don't want to glue the pipes together in case it clogs or something then I'd have to cut it all apart.

Is this the right pipe?
Not the same code numbers so I'm thinking with that crush rating you may be talking double insulated, but I'll check the local plumbing supply places and see what they say.

Thank fellas for the help


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## copcarcollector (Aug 8, 2012)

I have the Grizzly 3HP dual canister model. I used 6 inch HVAC ducting from Home Depot. These go to 4 inch reducers to blast gates, then 4 inch flex hose to the machines. For the joints, I used (a lot) of the aluminum duct tape (not the cloth stuff), but no fasteners. Works great so far. Have fun with your install!


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## Grandpa (Jan 28, 2011)

I bought 6 inch Spiral Wrap metal pipe for the same cost as they want for the PVC. Use the metal duct tape. I cannot remember the brand right now but I used a caulk that was recommended by ClearVue. I bought it at ACE hardware and it is easy to work with and not expensive. $3 or $4 a tube and it goes a long ways. Look up ClearVue CV 1800 and the installation instructions are on line. 
I like the looks of this valve built by one of our fellow Lumber Jocks. Any system might benefit from one of these.

http://lumberjocks.com/topics/47616


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## shawnmasterson (Jan 24, 2013)

copcarcollector: close all your blast gates and let me know what happens. I collapsed 25' of 7" before I could hit the remote.

PurpLev: " metal is preferred because it has less friction " I disagree with this statement. Pvc is seamless and smooth as glass. And the fittings all have their flaws whether metal or pvc.

as for pipe selection if you choose PVC I went with S&D it is thinner than what you posted. as for fittings I bought the fittings with the rubber in them. They are a tight seal but a total PITA to work with. I got my 6" flex at a local hose supplier for $7 a foot, but it is the heavy black stuff for leaf vacs. Here is what my system looks like.


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## copcarcollector (Aug 8, 2012)

copcarcollector: close all your blast gates and let me know what happens. I collapsed 25' of 7" before I could hit the remote.

Done and no issues, ran for about 5 minutes with all blast gates closed, no problems. However I did find some very minor leaks in the system, mostly at the Y adapters, so I have to seal those up a bit more!


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## UpstateNYdude (Dec 20, 2012)

Alright so I think copcarcollector reeled me into doing the metal pipe its at least half the price of the 6" PVC if I buy the sewer drain (green pipe) or the regular DWV 4396 (white pipe) not mention all the fittings and Y's are way cheaper also.

Where do you have the valve located btw copcarcollector?


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## mporter (May 5, 2011)

I think I have the same DC as you, the one with the canister filter on top? I ran my shop with 4 inch pvc pipe. I left the 3 way way on and hooked the DC to 6 tools. It has worked great for two years now. Even through the 4 inch pipe it pulls all the chips from my grizzly saw all the way across my shop. I know there will be people that tell you that you have to use 6 inch pipe, but I didn't and it has worked for me. Running the pipes out right and running them smartly will do more good than spending more money for the 6 inch. The 4 inch stuff will run you about 1/5 the cost of 6 inch by the way.

I have never had any static shocks with the system, although it does make some static electricity. If it is running and you are right next to a pipe the hair on your arm will raise up.

It is impossible to ground pvc pipe, so don't even try it. I don't know how this tale got started, but you can't ground an insulator.

Do yourself a favor and turn that handle on top of the machine twice a day. I didn't do that for a while and I must have cleaned 30 lbs of dust out of the filter! It will amaze you how much dust it will hold.


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## copcarcollector (Aug 8, 2012)

Where do you have the valve located btw copcarcollector?

Valve-? What valve?


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## kizerpea (Dec 2, 2011)

Captferd has the same grizz collector all plumbed up in his projects..check his out.


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## UpstateNYdude (Dec 20, 2012)

The safety valve Grandpa posted but maybe I misread your post and you don't have one? If that's the case you have a good size leak somewhere for it not to collapse that 30 gauge pipe.


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## wapakfred (Jul 29, 2011)

That PVC you linked above is schedule 40, really heavy stuff. Like I said, there is a confusing mix of names…and being called DWV doesn't make it the PVC you want (if you wind up using it). The spec I listed above is the one you want (again, if you choose PVC). It's light enough to be able to hang easily (don't try hanging the schedule 40 by yourself). It can be tough to find, but I got mine at a regional lumber yard called Carter's Lumber for about $16 for a 10' stick. Some box stores carry it, some don't…you almost have to check individually. To repeat something else, consider the costs with the fittings….the straight part is probably actually the cheapest of the total system.


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## shawnmasterson (Jan 24, 2013)

Thank you upstate thats what I am saying, or that just proves that it is not doesn't move what it claims.

+1 for fred. I got mine at a plumbing supply house. the pipe was $2 a foot, and the fittings were well over $10 each and I think the Y's were like $18-$20. the fitting will be the most costly part of the venture.

If I were you I would check the size of the impeller on your DC. if it is 12" or less it will never move 1700 cfm. you may be served well by 4" pipe depending on how long the run is. there is a point of to large of a pipe. The larger the pipe the slower the air moves, to a certain point. I am offering you a link to Bill Pentz's page. I am not saying his page is gospel but there is a lot of factual information in one place. It all depends on what you are in search of. If you want 100% collection, or just a fairly clean place to work.


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## Perrison (Jul 27, 2012)

you guys should check out these links here and here


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## copcarcollector (Aug 8, 2012)

No safety valve, never heard of that before. No good size leak, just a couple of small ones at a couple of Y fittings, all of which will be sealed asap!


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## mporter (May 5, 2011)

copcarcollector,

I like the setup in your picture, but for your setup to run as efficiently as possible you need to get rid of as much of the extra flex hose as you can. You have way too much going to your tools. Just some advise, take it if you want.


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## copcarcollector (Aug 8, 2012)

Thanks Mporter, I was trying to keep the blast gates at a nice operating height… I will make adjustments when I get the time!


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## mporter (May 5, 2011)

Copcarcollector, 
Now that you said that, I do like the blast gate heights. I have to bend over to get to mine. Hey if it works-then it works. You have more hp in your system than I do.


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## UpstateNYdude (Dec 20, 2012)

This is my DC it has a 12 3/4" impeller which from what I've read and researched is more then adequate for pulling down 1600-1700cfm suction capacity granted that's in an airtight seamless system with perfect runs I'm sure but I'm sure it could at the very least reach 1500.

As for the cost I fully understand the fittings will be the bulk of my price, well that and flex hose.

But I cannot find any of the thin wall any place or someone special is working at the 3 local plumbing supply places I've called (although one the guy said they were out and wouldn't have any for a week) so I'm thinking I may just go with the HVAC ducting like copcar but I dunno we'll see this weekend what I can find, there are a couple places farther south that have bigger plumbing supply distributors.

I plan to make my own blast gates as a friend has a CNC and can do the repetitive cuts for me, I'll hopefully get this sorted this weekend and come up with a plan.


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## shawnmasterson (Jan 24, 2013)

I realize the specs say 1600-1700, but thats not possible. It is really just logic. A clearvue CV1800 only pulls 1,442cfm and it has a 5HP with a 15" impeller. How could a 2HP with a 12 3/4" impeller pull 1600-1700 cfm??

IMHO with the DC you linked I would set it up center so you could run a 4" line left and right to pick up the whole shop. I think this would give you better performance.


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## copcarcollector (Aug 8, 2012)

Another reason for the excess flex hose is those machines are on mobile bases, so I can shift them around as needed and they are still hooked into the dust collection system…


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