A (maybe) new DC Duct Question

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Forum topic by kocgolf posted 06-05-2017 12:18 PM 1530 views 0 times favorited 15 replies Add to Favorites Watch
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408 posts in 2945 days

06-05-2017 12:18 PM

I realize these ducting questioning are done to death, but this might be a new one.

I have a huge outfeed assembly table. just more than 4×8. The family likes to play ping pong on it in the winter. I just roll the table saw out of the way.

Now, I am in the process of adding permanent ducts for a corner mounted Super Dust Deputy and HF powered system. It will either be 5” galvanized piping or 4” PVC. I prefer the 5”, but can’t find 5 inch metal wye’s anywhere. The bigger problem comes in when trying to figure out how to have a drop from ceiling for the table saw that can somehow be moved out of the way, or pivoted up or down to make room for ping pong.

I have considered a short flex section at the top where the drop starts, maybe just 6 inches. I could then use a rubber coupler at the bottom that I could loosen to detach and then pivot the whole “pipe stack” up to the ceiling. I want to stay away from flex tubing as much as possible, but a couple inches might be ok. I think the biggest problem with that is how to make the drop secure as it won’t be rigid and there will be a lot of weight hanging on that flex portion. I could maybe attach the bottom of the stack to the table with something, but it would still have to be removable somehow. If it was metal duct it wouldn’t be so heavy, but PVC seems a bit heavy to support this way.

This is weird, I know, and I bet the most common suggestion will be “forget the table tennis and focus on woodworking,” but it’s a fund family thing in the winter that makes the heated garage worth it for the whole family!

15 replies so far

View Mechanical_Max's profile


8 posts in 1131 days

#1 posted 06-05-2017 04:14 PM

I would look into some sort of hinge that you could mount to the ceiling and then secure the drop down piping to. You would still be using the flex section, but you would be able to support the weight of the drop down pipe with the hinge and then just install a rope loop or something to hold the end of the pipe in the up position. I’m not sure if my description is adequate, but hopefully you can understand what I mean. If not, let me know and I’ll try to explain better or draw something up. Hope this helps!

Best Regards,


View pintodeluxe's profile


6149 posts in 3580 days

#2 posted 06-05-2017 04:48 PM

The 5” metal pipe is just part of the game when playing ping pong at your house. Play around it! Play it as it lies, like in golf, right? We once rented a house on the coast and it had a badly warped ping pong table, presumably from being left outside occasionally. We had more fun playing on that table than the good one at home.

I would go with metal pipe though. I recently installed 6” pipe for my system and I have no regrets.
Plastic is the worst in regards to static shock. Even the longer lengths of flex hose I have needed to be grounded to the pipe to avoid static shock coming through the planer and sander. Even if you don’t believe the purported fire risk, the convenience of not getting zapped constantly while using your tools is worth it.

My 6” metal system costs the same as 4” PVC ductwork by the way. The key is to special order the fittings from a home center. They can get 26 gauge pipe, they just don’t stock it. Much, much, much less expensive than the specialty woodworking retailers.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View kocgolf's profile


408 posts in 2945 days

#3 posted 06-05-2017 06:12 PM

Thanks for the heads up on the metal vs pvc. It is the “great debate” afterall. I was leaning towards just doing 4” metal because of fittings, but I think I will call up some hvac and home centers and see what the options are for 5” wyes. The stuff from Oneida is just not doable for me at $35 per wye.

As it goes right now, I am starting to consider using the drop at the wall that is already planned and then laying the flex joint down right there at the wall and run 4 feet across the floor to the under the assembly table run. Yes, this poses a potential trip hazard, but realistically that is minimal, and it would be easier to access the pipe for disconnect and easier to fold up against a wall and keep all secure. It just seems to make more sense for my needs. Could always be changed later. Plus I am used to dodging the retractable hose right now as it as:)

View mrg's profile


866 posts in 3766 days

#4 posted 06-05-2017 08:10 PM

If you are using PVC don’t glue it at the drop. Put a couple of eye lids for bungie cords. Disconnect from table saw rotate pipe up and hold in place with bungie cords. The weight is minimal and the pipe will be out of the way for ping pong.

-- mrg

View AZWoody's profile


1477 posts in 1991 days

#5 posted 06-05-2017 08:25 PM

I would do as much searching as you can for 5”. I was very disappointed with 4” ducting and the HF dust collector when I had one.

View kocgolf's profile


408 posts in 2945 days

#6 posted 06-05-2017 09:57 PM

Thanks mrg. That’s a great thought. I had heard if angles and lengths and fittings were right that glue may be unnecessary for pvc. I certainly appreciate what AZ and others have to add on going to 5”, I just can’t justify the cost. I spent the afternoon looking locally for 5” fittings, but after 4 HVAC places couldn’t find them, I give up. Best I can find online is about 30 each for wye fittings, plus shipping, and I just can’t justify it at this point.

View AZWoody's profile


1477 posts in 1991 days

#7 posted 06-05-2017 10:06 PM

If you are using PVC don t glue it at the drop. Put a couple of eye lids for bungie cords. Disconnect from table saw rotate pipe up and hold in place with bungie cords. The weight is minimal and the pipe will be out of the way for ping pong.

- mrg

One problem I have with pvc is that after setting for a while in my system, it is difficult to pull apart, even with no glue.
If the pipe is fully seated inside the fitting, it won’t swivel. The only thing I can think of is putting some kind of silicon lube or graphite spray when assembling.

I just did a big revamp of my tools and moved them around so that meant pulling apart a lot of the pvc ducting and many pieces of pipe had to be cut out of the fitting and all I did was slide the piece in and used a small screw to hold in place.

View kocgolf's profile


408 posts in 2945 days

#8 posted 06-05-2017 10:40 PM

You know, I just realized I have a Dust Rite connector that has full swivel. If I put that in-line in the straight section across the ceiling, than a 4” to 4” rubber coupler at the bottom near the table, all I have to do is disconnect at the button and then swivel the whole stack up to the ceiling. Might have to test that. I can see how the fittings might get too tight with pvc, so maybe “splurging” on a couple would worth it.

View jonah's profile


2119 posts in 4065 days

#9 posted 06-06-2017 12:05 AM

What about running the pipe along the floor at the midpoint of the table (where the fence is)? You might be tripping over it during normal use, but I imagine once you get used to it that’d stop pretty quick. It wouldn’t be in the way of ping pong at all. Basically drop down behind your band saw and across the walking path from there to the outfeed table.

View kocgolf's profile


408 posts in 2945 days

#10 posted 06-06-2017 01:31 AM

Yes, a short run across the floor would be the least labor intensive initially and also the least invasive at game time, but I just don’t know if I can deal with the trip hazard. I initially thought I could and that this would probably be the best option, but the more I think about it the more I realize how much I hate dodging the flex hose right now. Not to mention that it would have to lay either right where I stand to use the bandsaw or else right in the middle of the main area I am working from when assembling. I don’t know. I think I will try the center drop with rotation point, and if it just isn’t smooth or is too much work to unhook and secure each time, then I will give the floor run a try. Maybe I will even leave a capped pipe against the wall that I can run from in the future if it comes to that.

Just like to say how awesome LJ has always been when it comes to this types of questions. Always so many great suggestions and willing helpers! Thanks!

View jonah's profile


2119 posts in 4065 days

#11 posted 06-06-2017 02:23 AM

I spent a few years stepping over a flex hose in my last shop, so it doesn’t seem like a big deal to me. Your mileage, obviously, may vary.

View JBrow's profile


1368 posts in 1687 days

#12 posted 06-06-2017 01:37 PM


5” x 5” x 5”, 5” X 5” X 4”, and 5” X 4” X 4” sheet metal wyes can be found at…

A twist lock connector could possibly be used as a means to connect and disconnect rigid pipe that drops from the ceiling. However, some support of the down pipe might be required to reduce the strain on the J lock of the quick disconnect.

At one time, Penn State Industries carried metal J lock quick disconnects but buying it on-line may not be possible or it has been discontinued. A call to Penn State may be required to determine whether the metal disconnect is still available. Click on “Quick Disconnect” to get Penn State’s phone number.

The only alternative to the Penn State J Lock disconnect that I found is Fazlok. It is made of plastic so I am not sure how much weight or abuse it can tolerate.

A quick disconnect could even be shop-made with PVC or metal pipe. Plywood meeting plates mounted to the male and female pipes would interlock and keep the pipe connection together.

One option for keeping the meeting plates together is to make the upper (ceiling) meeting plate with a hole sized to slip over the outside of the pipe along with a pair of slots. The lower (down pipe) meeting plate would have a pair of carriage bolts secured with T nuts and that align with the upper meeting plate slots. The down pipe would slip into the ceiling-mounted pipe and the carriage bolts would slip through a pair of oversized holes drilled to allow the head of the carriage bolts to pass through the upper meeting plate. Then a twist of the down pipe would seat the carriage bolts in the slots where the heads of the carriage bolts would keep the connection together.

If you elect to try this shop-made disconnect with PVC pipe, a light coating of grease on the male end of the pipe would make connecting and disconnecting the pipe easier.

A second approach would be to create the upper meeting plate with slots into which the lower meeting plate slides. In this option, the pipes would need to be recessed into the meeting plates.

I suspect that any of these quick disconnect approaches will leak a little at the disconnect joint.

View kocgolf's profile


408 posts in 2945 days

#13 posted 06-06-2017 02:09 PM

JBrow, thank you! The twist lock method is not something I had even thought of. A definite possibly! Also, while I am not completely sure I follow what you are describing for the shop made version, your idea on it has the wheels turning in my head on how to do it a few different ways.

I had found KenCraft from a local friend suggestion. At this point I am just not sure that I want to add in that cost. I will need at least 6 or 7 wye connections from what I can tell. It might just be too much investment. I will definitely budget all these options out. If it seems reasonable, or at least not obscenely more, I will go with 5 inch. I don’t want to regret it later if I chose 4 inch to save 50 bucks.

I think at this point it is likely I will go with the 4” pvc, partly because of the easier adjustability. I will try a couple overhead drop methods, and if all are annoying to disconnect, or cause leakage, then I will experiment with the floor method. Heck, I might just lay a pipe in my way for a few months and see how much I notice it. If it doesn’t bother me, then I will probably go with that.

View Sark's profile


268 posts in 1127 days

#14 posted 06-11-2017 02:34 PM

I think PVC is great for a small shop…easy to install, modify and less expensive than metal, at least the thin schedule 20 stuff. I bought 6” pvc drain pipe and fittings from a local irrigation supplier. Static can be managed somewhat by running some metal tape along the outside, and grounding it. At least that’s how I did it at my shop which was 2300 sq. ft. I don’t know if 5” PVC is sold, but never looked for it. Metal is so hard to work with compared to PVC, I wouldn’t go down that path.

View TheFalconJetDriver's profile


5 posts in 1046 days

#15 posted 09-24-2017 04:44 AM

5 inch ducting solutions!
I too have the exact situation with ducting, I need to drop my 5 inch HVAC duct from the ceiling to my table saw with a wye one leg going to the bottom of the TS and the other going to the overhead D.C. For the TS.
I am in a small two car garage and a perminate drop from the ceiling would impead my ability to move large stock to the table saw, so the concept of a hinged swing up and out of the way duct just may work for me.
I also have a HF DC with a SDD Cyclone with a Wynn 35A filter. It all works well together
To see my setup look for my posting on “Another HF DC” I mounted the blower inline with The SDD by making a new cover plate for the fan section and using a 6 inch HVAC duct that fits directly into the 6 inch suction side of the SDD.
As for 5 inch WYES I found them at Woodcrafters for $14.99 each, a local Sheet metal shop offered to make make them for $30.00 each. I bought adjustable 90’s at a HVAC shop for $1.89 big box stores wanted $6.00
For couplings for 5 inch flex I found that Lowes has snap drain pipe connector ABS black plastic for gutter drains $1.99. With this coupling I knock out the tabs on the inside with a wood chisel the coupler then slides into the flex duct.
This same coupling is a perfect fit for the coupling connecting my output of the HF blower out put and the input of the
Circular ring my plastic bag hangs off of and the Wynn filter sitts on.
I also us this same coupling to reduce from 5 inch flex to a short 4 inches 4 inch flex connected to my tools.
I use a ASTM 2729 4 inch coupling this is light weight drain pipe. The two couplings fit inside of each other. Yes the od of the 4 inch is smaller than the od of the snap drain coupling. Using foil HVAC tape I tape the two couplings together. I did cut some short 3/8 by 1 inch shims to take up the slack between the two couplings.

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