Dust Collection Ductwork

[Steve Aiken]

I'm finally getting around to starting my ductwork installation for my Dust Gorilla. A couple questions....

1. Are Spiral pipe and snaplock pipe and fittings interchangeable? I notice on the Oneida site that they have both types of pipe, but they do not seem to have specific fittings for spiral pipe -e.g. lateral wyes, etc.

2. For anyone that has used the Oneida snaplock.... is there crimping on the parts more 'delicate' than the crimping found on standard HVAC fittings? It looks that way on the online catalogue, but it's hard to tell.

Steve

[keith ouellette]

I don't know how far you have gotten or if this is of use.
I use 4" pvc waist line. I figured the cost and it was much less than metal duct and is easy to cut. 4" gate fit on it with a adhesive caulk to hold the gate on air tight. If i remember it was half the price of the items your talking about. I never got around to grounding it and have no problems as of yet wit h static charge.

[Steven Wilson]

The crimping on the Oneida snaplock pipe is fine. It is helpful to have a crimper around when you're installing stuff though. Sometimes to get a good fit you may need to add a little extra crimp to the snaplock or the fittings, but that's not unique to Oneida's material.

As for 4" pvc, why would anyone want to downgrade their installation by going with 4" PVC?

[Larry Rasmussen]

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. Hopefully Steve Aiken you got your info on the crimping though, let us know how the installation goes. I'll probably still be procrastinating on mine.

Larry Rasmussen
Seattle

[keith ouellette]

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.

[Steve Aiken]

Are Spiral pipe and snaplock pipe and fittings interchangeable? I notice on the Oneida site that they have both types of pipe, but they do not seem to have specific fittings for spiral pipe -e.g. lateral wyes, etc.

It appears that there are 2 types of wyes available - those with crimping on one end, and those without. Are the 2 types interchangeable?

Steve

[Chris Padilla]

From all the research I've seen and done, one normally comes out better going with the larger 6" pipe versus 4". Go at least 5" if you can (but PVC isn't available in 5" if PVC is your material of choice).

I hemmed and hawed for several months over metal vs. PVC and finally went PVC. Everything I have is 6".

Crimpers can be had at Home Depot (that is where I got mine) as well as other helpful/special sheetmetal-working handtools.

[Chris McKimson]

Steve,

When I got my quotes from Onieda for both snap lock and spiral for my 3HP Gorilla, the spiral quote included some necessary adapters to transition between the spiral and the fittings. That and the lack of free shipping (included with the snap lock) drove the price of the spiral up quite a bit. I ended up getting spiral from Sprial Mfg. The cost of spiral + shipping from them was less than Onieda's snap lock and I feel I got a better product. I've included a pic of one of the runs.

I'm not sure Steve was dogging PVC per se, but I read that to mean why would you want to use 4" ducting of any kind with your Oneida cyclone. I went with a combination of 8", 7", 6" and 5" and reduced to 4" only at the tool when necessary.

[Bob Genovesi]

I don't know how far you have gotten or if this is of use.
I use 4" pvc waist line. I figured the cost and it was much less than metal duct and is easy to cut. 4" gate fit on it with a adhesive caulk to hold the gate on air tight. If i remember it was half the price of the items your talking about. I never got around to grounding it and have no problems as of yet wit h static charge.

I'll have to agree with this, I did the same thing and it works perfectly. The only connections I sealed was where I installed the blast gates. It is not noisy and I have never been zapped, not even once.

As for 4" pvc, why would anyone want to downgrade their installation by going with 4" PVC?

The answer is quite simple; It Works.....

[Jim Becker]

I'm not sure Steve was dogging PVC per se, but I read that to mean why would you want to use 4" ducting of any kind with your Oneida cyclone. I went with a combination of 8", 7", 6" and 5" and reduced to 4" only at the tool when necessary.

I agree with this. Properly sized duct work is essential to maintain system performance regardless of what material it is made of. The maximum CFM you can pull through a 4" duct at typical velocities is in the neighborhood of 300-350 CFM. Stepping up to even 5", which is often an ideal drop size, will get you closer to 600 CFM. 6" moves that up closer to 700-800 CFM. And these cyclones have every bit the ability to leverage that, especially when the machine hoods are also optimized.

To the OP, in case you didn't see it, spiral will use the same wyes and laterals, but a coupler/adapter is used for the connections. The same coupler is used between sections of straight pipe. If you can find a local source for spiral, it's great stuff; otherwise, 26 gage snap lock works just fine. You can often source the straight pipe from a local HVAC supplier, too...it's sometimes referred to as "stove pipe" as that is one of its applications.

[Steve Aiken]

I'm assuming that if you used a 45 degree lateral wye or tee-on-taper designed for spiral pipe (like this http://www.airhand.com/product.asp?C...bCategoryID=24) that you'd have to crimp the end closest to the dust collector. It looks like the advantage of Oneida's wyes and tees is that they come pre-crimped (http://store.oneida-air.com/item.asp?cID=0&PID=388).

I have decided that I will not be using PVC, and I will be using the ductwork plan that Oneida prepared for me to size the ducting.

Thanks for your help.

Steve

[Steve Sawyer]

I have been discussing this issue - both price and performance - with members of my local WW club.

My plans call for a 220v 2HP 1600 CFM unit, and after going 'round and 'round here's what I THINK I'm going to do - comments and criticisms welcome.

• PVC S&D pipe and fittings
• 6" from the chip separator (might upgrade to a cyclone someday, though with 80" ceilings that might not be possible) through about 15ft of horizontal run including one right-angle turn.
• 6" drop to a 4" flex hose for my mobile machinery (jointer, planer, band saw)
• 4" drop through a wye with 4" flex hose to the TS and a 3" port to the overarm guard.
• 6" drop to a home-made floor sweep.

As you can see I'm going with the larger-is-better philosophy. The area of the 4" TS port and overarm gaurd vacuum probably exceed that of the 6" pipe, but I'm hedging my bets by sticking with the 4" ports on the mobile machines. The chip discharge chute on the jointer is only about 4.5" wide, so I'm kinda stuck there. The port on the planer (DW735) is fixed at 4" (but has a built-in exhaust fan), and increasing the size of the port on the steel-frame band saw will require major surgery.

This is NOT going to be cheap - just the two 90 degree elbows and the three 6" wyes are going to run about $125. PVC fittings (even S&D) take a huge jump in price (about 4x) between 4" and 6".

However, I've decided that the smoothness of the surface, the ease of installation and sealing, and the somewhat lower cost make PVC a much better choice.

[Chris Padilla]

Mr. Sawyer,

That all sounds good to me but I'd take 6" as far as I could stand it. I understand that some machines are stuck at the dust port they were born with but you might try getting a taper fitting there. For my oddball 120 mm port on my MM FS-41Elite J/P, I had Oneida whip me up a nice taper for that to 6". With this, I'm necking down for about 8" or so and not several feet. Also, a taper is better than an abrupt change.

McMaster-Carr is a great source of S&D fitting for your 6" S&D: http://www.mcmaster.com/

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

No, this isn't cheap. Lottsa money in ductwork whether it is plastic or metal.

[Jim Becker]

Steve, you're likely to find that you're not going to be happy with a chip separator, unless it's actually a cyclone, with that DC unit...with 6" duct, the real CFM will (which is still much less than the rating from the manufacturer......like half) will clear all the material from the separator anyway. You can buy add-on cyclones which will fit in your space from Oneida, etc., or build them to suit.

[Mike Monroe]

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.