D.O.G. Simple Approach for Dust Collection Ducting

Creating Better Dust Collection for Your Woodworking Power Tools If you have made an investment in a powerful dust collector, that is a great first step toward creating a healthy shop environment. For purposes of this article I will assume that you have worked with your vendor to choose a dust collector that is capable of delivering enough air flow (ideally 1000 cubic feet per minute at 4000 feet per minute) at each tool to remove all of the fine dust that it produces (bare minimum 2HP with 12″ impeller for 400 sq. ft. shop, but do yourself a favor and don’t skimp). Now you want to make sure that you are doing everything you can to get the most out of it. First, unless you want to jockey a hose from tool to tool each time you make a cut (don’t kid yourself; that’s a pain), you will need to set up ductwork to draw dust from each tool in your shop to your centralized dust collector. Proper duct design is perhaps the least understood topic related to dust collection, and it is critical that you study on this to get it right in your shop. I would argue that many of the products that are sold in this category are not up to the task of removing.

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Let the dust collector “do its thing”.

Proper ductwork is all about providing a network that allows air to be pulled from each tool individually at ample velocity, and moving enough air volume to remove both the chips and the very fine dust produced. The primary enemy of ideal dust collection is static pressure. In applied terms you can think of static pressure as the force that restricts air flow. The things that increase static pressure in dust collection include smaller ducts, longer distances, bends in the pipe and flexible tubing, so we will focus our efforts in minimizing those things that materially increase static pressure in our systems.

Dust collection duct design is a complex science, and I am going to intentionally oversimplify it because I think the basics can be lost in the gory detail, and by following a few basic guidelines it is easy enough to achieve air flow that is “good enough”. Toward my goal of oversimplification, I offer the “D.O.G. Simple” method of small shop dust collection ductwork design:

- D = Direct; keep your duct runs as short as possible. Longer runs create higher static pressure and poorer performance.

- O = Open; bigger diameter pipes allow more air movement and introduce less static pressure, assuming you have a dust collector that can move air fast enough through the pipe.

- G = Gentle; to make it easier for dust to travel through pipes, use smooth wall pipes (minimize flex pipe), and when turns are necessary, make them as gentle and gradual as possible.


First, choose your weapon: PVC or Metal

Creating Better Dust Collection for Your Woodworking Power ToolsPVC or Metal? First you need to choose a material for your duct work. Either PVC or metal will work well. If you choose metal, you should use 26 gauge or thicker so it doesn’t have the potential to collapse under suction pressure. Also, consider spiral pipe which is more durable and easier to seal, although more costly. The HVAC piping in most home centers is 30 gauge or thinner, so it is not a good choice for dust collection. You will need to buy from either a dust collection vendor or a HVAC vendor who carries heavier gauge ductwork. Buying local might provide savings due to the high shipping costs of large pipes.

If you choose PVC, be aware that there are different thicknesses on the market, and you should go with the thinnest stuff you can find. This will generally be referred to as “Sewer and Drain”, sometimes referred to as ASTM d-3034 or ASTM D-2729. The thinner and lighter the PVC, the easier to work with. Do not get schedule 40 or 80, because these are expensive and heavy, and all of the extra mass is wasted on dust collection which places extremely low pressure on PVC relative to plumbing applications which generally dictate schedule 40 or 80. To maximize your air flow, focus most of your design efforts around 6″ pipe, sometimes 4″ when you need to, but nothing smaller than that for stationary tools.


Creating Better Dust Collection for Your Woodworking Power ToolsI use PVC because I find it to be much cheaper in my area, and I prefer working with it over metal. But if I didn’t have good access to PVC pipe and fittings, I would be comfortable going with metal as well. To cut PVC I simply use a jig saw with whatever wood cutting blade I happen to have on the saw, and it zips right through it.

Does PVC need to be grounded (or can it be grounded)? These are hotly debated topics all over the internet. I have never heard of an actual example of a fire resulting from static discharge, but there is a potential that you may get static electricity shocks from your PVC duct system if you live in a dry climate. If this is your situation you can find many suggestions around the internet for grounding your PVC ductwork. I have never gotten a shock in 10 years of running PVC ducting in two different shops, so I have never bothered with grounding mine.


The D.O.G. Simple Method in Detail

Creating Better Dust Collection for Your Woodworking Power Tools“D” is for Direct. Make your duct runs straight and direct with as few turns as possible. Arrange your tools in such a way that the bigger dust producers (table saw, planer, etc.) are closest to the dust collector, as airflow will be greatest on your shortest runs. One common mistake is to run ductwork that follows the perimeter of the room, which requires longer runs and more turns in the ductwork for some tools, and performance suffers as a result.

“O” is for Open. Size matters in dust collection. If your duct is too small, you won’t move adequate air volume to remove fine dust, but if it is too large, you won’t get sufficient air speed to remove anything. Therefore it is important to have your duct layout in mind when you buy your dust collector, and have your vendor suggest a model that can deliver enough suction at your tools. If you have chosen a dust collector with enough suction for your shop configuration, then the simplest approach with PVC is to run 6″ pipe wherever it is feasible, and 4″ pipe wherever you find it necessary. That means you will likely have to modify tool ports on some tools, which I will discuss a bit later in the article. It is not that hard, and it is well worth the effort. With metal ducting there are additional sizes available, and you can make more gradual steps down to potentially squeeze a bit more performance out of your system, but if you have appropriately sized your dust collector, you will be able to derive adequate air flow using 6″ and 4″ pipes.

“G” is for Gentle. The goal is to make long gentle transitions so that dust doesn’t slow down too much going around curves and through reductions in pipe size. Pretend you are designing a race car track, and you want to keep the cars going at high speeds into the turn, because once they slow down it is hard to get them moving fast again, and we want to avoid a pileup of cars, or in our case, dust. Specific choices that help promote gentle dust paths include:

Creating Better Dust Collection for Your Woodworking Power Tools45s not 90s. Rather than a short radius 90 degree turn, incorporate two 45 degree bends with a section of straight pipe in the middle, which will allow the particles to scream right through the turn. If you can find elbows that are specially designed as “long sweep” elbows, you can use these, but they are not commonly available in my area.
Creating Better Dust Collection for Your Woodworking Power ToolsWyes not Tees. For the same reason as the elbows discussion, when you need to split the pipe into multiple runs, use a wye fitting rather than a tee, followed by a section of straight pipe, and then another 45 degree turn if necessary. Again, this will allow the dust to move through here without slowing down as much and potentially building up in the pipe over time. I have particularly found this beneficial for my table saw, where I routinely get longer pieces (thin rips that fall through the throat plate) pulled through the ductwork.
Creating Better Dust Collection for Your Woodworking Power ToolsTapered vs. abrupt reducers. When you need to drop down to a smaller duct size in line, use a reducer with a smooth taper rather than an abrupt reduction. This will promote better air flow and reduce turbulence in the pipe.
Creating Better Dust Collection for Your Woodworking Power ToolsMinimize the flex pipe. Run hard pipe as close to the tool as possible, and use just the flex pipe you need for convenience in case you need to move the tool. Also, choose a good quality flex pipe with smooth interior walls that was designed specifically for dust collection. Some of the cheaper stuff I have used is extremely rigid, making it terrible to work with. Good flex pipe is expensive, so I am sufficiently motivated to minimize it for that reason as well.

Other ducting suggestions

Creating Better Dust Collection for Your Woodworking Power ToolsExtra ports. When you set up your ductwork consider installing additional ports at logical locations for possible future expansion. It is easier to do it now rather than pulling your ducts apart later. You can add a blast gate so you are ready to go, or simply place a cap on the pipe which is a bit cheaper. This can also provide a nice cleanout in a convenient location should something ever get lodged in your ductwork.
Creating Better Dust Collection for Your Woodworking Power ToolsSeal the joints? If you use PVC, particularly 6″ where there is so much overlap at the joints, you shouldn’t need to seal most of your joints. In a couple key areas, such as where the duct work connects to the dust collector, I use X-Treme tape to seal the joint. This tape does not leave glue residue, so when you rework your ducting it is easy to remove and does not require cleanup. I don’t like using duct tape, or caulk, on ducts as I feel it is not necessary on PVC. On metal you will likely need to seal the joints to minimize leaking.


Creating Better Dust Collection for Your Woodworking Power ToolsAdd screws wherever needed to secure joints. On vertical runs, and some horizontal runs where connections are slightly loose, I put a couple #8 x 1/2″ self tapping sheet metal screws into the joint to hold it securely. These are easily removed when rearranging ducts.
Creating Better Dust Collection for Your Woodworking Power ToolsAttach ducts to a stud using plumber’s strapping. Regular old metal plumber’s strap provides an effective and economical means of securing ducts to your walls and ceiling. Attach using 1-1/4″ drywall screws. A couple straps per 10 feet of pipe should be adequate to hold everything solid.
Creating Better Dust Collection for Your Woodworking Power ToolsBlast gates and tool portsBlast gates. There are many different options out there. If you use metal ducts, then you should use metal blast gates. I use some metal ones on my PVC ducts as well because they are more durable than the cheap plastic ones. If I were starting from scratch I would use the blast gates from Clear Vue Cyclones for all of my 6″ ducts, because they are far better quality than the cheap plastic ones, and they provide better air flow than the metal ones because they sit on the outside of the pipe rather than the inside. I have also seen plans for shop made blast gates using PVC and plywood which are quite cool, but I haven’t been able to justify the time to build these.


Creating Better Dust Collection for Your Woodworking Power ToolsTool ports. I encourage you to accept the fact that most tools come with insufficient tool ports. In the last five years or so, this seems to be improving, but is still not great. Keeping in mind that ideally you will place a 6″ port as close to where the dust is being produced as possible, and I have never purchased a tool that had a standard 6″ port, or even an optional one for that matter. So, you will have to make your own ports, and in some cases, cut holes in your tools to accommodate the port. The picture shows a shop made 6″ port on a jointer, with a drill stuck in it to illustrate the massive size. That port allows massive air movement, and allows my dust collector to pull everything that is not attached to the tool.


Creating Better Dust Collection for Your Woodworking Power ToolsSimple to make. Take a 6″ piece of PVC, set it on a piece of plywood or MDF, trace a line around the outside of the pipe, and cut the hole. Set the PVC in the hole and caulk it on the outside. Then place ” foam weather stripping around the perimeter of the plywood, and use sheet metal screws to attach to your tool. If the stock port opening on the tool isn’t large enough, or isn’t there, use a jigsaw with appropriate metal cutting blade to modify or create the opening.
Creating Better Dust Collection for Your Woodworking Power ToolsQuick disconnect with standard PVC coupler. Here is an effective ways to make quick disconnect fittings for 4″ and 6″ PVC. Use a standard PVC coupler to slip easily over the opening on your shop made tool port. Then insert your flex pipe into the other end of the coupler. I have found this to be a perfect fit on both 4″ and 6″ ducting, requiring only a pressure fit to stay on, with little noticeable air leak. If the fit is a bit loose, you could use X-treme tape or duct tape to hold it solidly and seal it. I like these much better than commercially available quick disconnect systems, plus I have not seen commercially available quick disconnects for 6″ ducting. With a good system for quick disconnect, it is simple to share a duct between two tools if you prefer, and it allows you to keep your flex hose runs shorter to minimize static pressure because moving a tool for cleaning, maintenance, etc. only requires a simple disconnect process.

Summary. If you want to dive into more detail on this topic, some of the dust collection vendors offer guidelines and services in this area, and independent researchers such as Bill Pentz provide extensive information on this topic as well. For most small shop environments, however, I am confident that if you follow these basic guidelines to design your ductwork and power it with a dust collector that is capable of pulling through an adequate volume of air, you will be pleased (or even amazed) with the performance.

Once designed your system to deliver enough air flow, the next thing you need to think about is how to best corral the dust at each tool. Some tools provide adequate dust collection ports, while others (most) don’t and you will need to devise your own enhancements. In a separate article I will walk through the dust collection design at each tool in my shop to help you complete your dust collection system design.

Watch the next newsletter for specifics on how I optimized dust collection at various tools in my shop.

Photos By Author

Source:
X-Treme Tape, Self fusing silicone rubber tape 20 ft. roll, $14.99
www.xtremetape.com

800-867-8968

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  • Anonymous

    This is very interesting.

  • Anonymous

    This is very interesting.

  • texan63

    Great article and timely for me as I’m considering a dust collection system for my small workshop (one car garage stall) . The big issue is whether I should go with a bigger DC to support plumbing drops for each machine or a smaller DC unit and drag a hose around to each machine. Suggestions anyone??

  • texan63

    Great article and timely for me as I’m considering a dust collection system for my small workshop (one car garage stall) . The big issue is whether I should go with a bigger DC to support plumbing drops for each machine or a smaller DC unit and drag a hose around to each machine. Suggestions anyone??

  • Paul Mayer

    Hi texan,

    Thanks for the feedback. As to your question, you can probably guess what I would suggest which is a bigger DC and a ducting system. The benefits are significant. I go back and forth from tool to tool so frequently that I am nearly certain I would make many “quick cuts” without dust collection if I were setup that way. I also think that if you stick with woodworking long enough you will eventually upgrade your DC and add a ducting system, so if you believe that you will be doing woodworking in your current location for more than a year or two, I would consider biting the bullet now and getting into a system that will meet your needs for many years as it will actually save you money in the long run and give you a better experience up front. But I recognize the investment in time and $ is significant, so portable dust collection is a worthy consideration as well. If I were to get a portable system, I would do one of two things. Either buy one used from someone who has recently upgraded (there are lots of them out there in my area) or buy one that has enough power to collect from a ducting system if you decide to add that later. That way your investment is protected when you expand the system later, and all you need to buy are a bunch of plastic tubes and fittings.

  • Paul Mayer

    Hi texan,

    Thanks for the feedback. As to your question, you can probably guess what I would suggest which is a bigger DC and a ducting system. The benefits are significant. I go back and forth from tool to tool so frequently that I am nearly certain I would make many “quick cuts” without dust collection if I were setup that way. I also think that if you stick with woodworking long enough you will eventually upgrade your DC and add a ducting system, so if you believe that you will be doing woodworking in your current location for more than a year or two, I would consider biting the bullet now and getting into a system that will meet your needs for many years as it will actually save you money in the long run and give you a better experience up front. But I recognize the investment in time and $ is significant, so portable dust collection is a worthy consideration as well. If I were to get a portable system, I would do one of two things. Either buy one used from someone who has recently upgraded (there are lots of them out there in my area) or buy one that has enough power to collect from a ducting system if you decide to add that later. That way your investment is protected when you expand the system later, and all you need to buy are a bunch of plastic tubes and fittings.

  • standard

    I have used PVC for 15 years at least with no problem. I do recommend a direct connection to all machines and a open connection to portable machines that are used sometimes. every thing that is in the article is great, I made my blast gates from wood and metal with no problems, I use a first primary collection container before my dust bag to catch larger items so they do not go through my dist collection fan and you do not have to empty the dust bag as often. good luck

  • standard

    I have used PVC for 15 years at least with no problem. I do recommend a direct connection to all machines and a open connection to portable machines that are used sometimes. every thing that is in the article is great, I made my blast gates from wood and metal with no problems, I use a first primary collection container before my dust bag to catch larger items so they do not go through my dist collection fan and you do not have to empty the dust bag as often. good luck

  • Paul Mayer

    Standard,

    I would be interested in seeing your shop made blast gates if you are willing to post a photo of them in the Forum area.

  • Paul Mayer

    Standard,

    I would be interested in seeing your shop made blast gates if you are willing to post a photo of them in the Forum area.

  • Don

    I have been using a central dust collector system for over 10 years, utilizing both PVC and HVAC ducting. Great success with both. When using the HVAC ducting I recommend taping ALL joints and seams as this reduces air leaks and improves preformance.
    As ar as static discharge, living in the South it is typically humid, but there are some days I get zapped while using my orbital sander with the dust collection hose attached. Its fun.

  • Don

    I have been using a central dust collector system for over 10 years, utilizing both PVC and HVAC ducting. Great success with both. When using the HVAC ducting I recommend taping ALL joints and seams as this reduces air leaks and improves preformance.
    As ar as static discharge, living in the South it is typically humid, but there are some days I get zapped while using my orbital sander with the dust collection hose attached. Its fun.

  • MTAV

    I’m in the process of re-modelling my workshop and include a ducted system. I was just going to use 4″ duct as that is what is pushed by all the woodworking vendors on their sites and catalogs……now you have me thinking about 6″!!! I have a 2Hp 1200CFM DC. If 6″ is the way to go why then don’t the stores sell fittings for this size….go figure!

  • MTAV

    I’m in the process of re-modelling my workshop and include a ducted system. I was just going to use 4″ duct as that is what is pushed by all the woodworking vendors on their sites and catalogs……now you have me thinking about 6″!!! I have a 2Hp 1200CFM DC. If 6″ is the way to go why then don’t the stores sell fittings for this size….go figure!

  • Paul Mayer

    Hi MTAV,

    The lack of resources on this topic is disheartening. I think you will find that woodworking retailers are slowly getting up to speed on dust collection, but they are not on the cutting edge of research in this area. My guess is that 6″ PVC is so expensive and cumbersome for them to handle and ship, and it is relatively inexpensive at home centers, so it is hard for small retailers to get into this business. A 10′ length of 6″ PVC costs about $20 at a big box store, and it probably costs $100 to ship it to someone’s home. Companies that specialize in dust collection are much better versed on duct design, and in general where you find snaplock pipe they sell larger size pipe.

    As far as piping that dust collector for 6″, it depends on the actual CFM capability of the system (most DCs are rated much higher than they actually deliver), and the length of your duct runs. For short runs I think it will be fine, but for long runs you might not have the power to maintain 4000 fpm necessary to pull the finest dust. I would try to arrange your tools so that the big dust producers are closest to the DC, and pipe them using 6″. For tools that are farther away, you might need to drop down to 4″ to keep the air velocity up.

  • Paul Mayer

    Hi MTAV,

    The lack of resources on this topic is disheartening. I think you will find that woodworking retailers are slowly getting up to speed on dust collection, but they are not on the cutting edge of research in this area. My guess is that 6″ PVC is so expensive and cumbersome for them to handle and ship, and it is relatively inexpensive at home centers, so it is hard for small retailers to get into this business. A 10′ length of 6″ PVC costs about $20 at a big box store, and it probably costs $100 to ship it to someone’s home. Companies that specialize in dust collection are much better versed on duct design, and in general where you find snaplock pipe they sell larger size pipe.

    As far as piping that dust collector for 6″, it depends on the actual CFM capability of the system (most DCs are rated much higher than they actually deliver), and the length of your duct runs. For short runs I think it will be fine, but for long runs you might not have the power to maintain 4000 fpm necessary to pull the finest dust. I would try to arrange your tools so that the big dust producers are closest to the DC, and pipe them using 6″. For tools that are farther away, you might need to drop down to 4″ to keep the air velocity up.

  • Brent Stratton

    Hello Don, Great article! I currently have a 4 H.P. DC, with suction capacity of 3560 CFM and Static Pressure 16.8. It can be used with a 9 inch manifold with 4 – 4inch fittings or by removing the manifold and the connecting the DC directly to the main. My shop is located in a basement and space is tight so I have to use the manifold. I am planing to build a new dedicated shop and have many drawings of my tools placement and ducts layout. My plan is not to use the manifold and use a main instead. My question should I take advantage and use the largest duct I can find for the main then branch off of it with smaller ones? Or should I stick with the 6 inch ducts? I know the answer is basically on the length of the main and static pressure and design. I just keep going back and forth what to do off the main. In any case I am leaning heavily towards using PVC. In my research I found some web sites that may interest your readers. ‘Grounding PVC and Other Dust Collection Myths’ by Rod Cole: http://home.comcast.net/~rodec/woodworking/articles/DC_myths.html Source for those hard to find PVC fittings: http://www.pexsupply.com/PVC-Fittings-470000 Source self made blast gates: http://benchmark.20m.com/articles/BlastGate/blastgatebuilding.html Thanks, Brent

  • Brent Stratton

    Hello Don, Great article! I currently have a 4 H.P. DC, with suction capacity of 3560 CFM and Static Pressure 16.8. It can be used with a 9 inch manifold with 4 – 4inch fittings or by removing the manifold and the connecting the DC directly to the main. My shop is located in a basement and space is tight so I have to use the manifold. I am planing to build a new dedicated shop and have many drawings of my tools placement and ducts layout. My plan is not to use the manifold and use a main instead. My question should I take advantage and use the largest duct I can find for the main then branch off of it with smaller ones? Or should I stick with the 6 inch ducts? I know the answer is basically on the length of the main and static pressure and design. I just keep going back and forth what to do off the main. In any case I am leaning heavily towards using PVC. In my research I found some web sites that may interest your readers. ‘Grounding PVC and Other Dust Collection Myths’ by Rod Cole: http://home.comcast.net/~rodec/woodworking/articles/DC_myths.html Source for those hard to find PVC fittings: http://www.pexsupply.com/PVC-Fittings-470000 Source self made blast gates: http://benchmark.20m.com/articles/BlastGate/blastgatebuilding.html Thanks, Brent

  • Paul Mayer

    Hi Brent, I would be skeptical of a CFM rating that high on a 4hp machine, as many manufacturers use highly inflated CFM ratings which are probably based on a theoretical max, or something like that. I would encourage you to do some research on the specific machine to see if any owners are using pipe larger than 6″, and see how their performance is. Look for someone who can provide both FPM and CFM. You need to keep the air velocity up or dust will settle in the pipe and build up over time, which is the risk of oversizing the pipe. But if you can maintain adequate FPM through a larger trunk, and branch off to tools with smaller pipe, that is a winner. You might also try getting an air flow meter and experimenting with some various size pipes to see what you find. If you start dipping below 4000 FPM, you should reduce the size of pipe. Bigger is better until you get below that threshold. The results were quite interesting when I tested before & after my Clear Vue upgrade: http://www.wwgoa.com/articles/product-reviews/stepping-up-to-better-dust-collection/

  • Paul Mayer

    Hi Brent, I would be skeptical of a CFM rating that high on a 4hp machine, as many manufacturers use highly inflated CFM ratings which are probably based on a theoretical max, or something like that. I would encourage you to do some research on the specific machine to see if any owners are using pipe larger than 6″, and see how their performance is. Look for someone who can provide both FPM and CFM. You need to keep the air velocity up or dust will settle in the pipe and build up over time, which is the risk of oversizing the pipe. But if you can maintain adequate FPM through a larger trunk, and branch off to tools with smaller pipe, that is a winner. You might also try getting an air flow meter and experimenting with some various size pipes to see what you find. If you start dipping below 4000 FPM, you should reduce the size of pipe. Bigger is better until you get below that threshold. The results were quite interesting when I tested before & after my Clear Vue upgrade: http://www.wwgoa.com/articles/product-reviews/stepping-up-to-better-dust-collection/

  • texan63

    Hi Paul; here’s an update on my comment from a month ago. I took yours and others’ advice and purchased a system with capacity for the future: a 3HP cyclone type that I’ll use with a 5 inch dia. hose for now, but will be able to plumb in drops in the future if I move to a larger shop. The unit has lots of capacity, a very high MERV rating for the filter and low noise rating (75 dbA at 10 ft.). Thanks so much for your advice! Travis

  • texan63

    Hi Paul; here’s an update on my comment from a month ago. I took yours and others’ advice and purchased a system with capacity for the future: a 3HP cyclone type that I’ll use with a 5 inch dia. hose for now, but will be able to plumb in drops in the future if I move to a larger shop. The unit has lots of capacity, a very high MERV rating for the filter and low noise rating (75 dbA at 10 ft.). Thanks so much for your advice! Travis

  • paul

    Hi Travis,

    Cool! Sounds like a great system and really quiet. Would love to see a pic once you are up and running…

    Paul

  • paul

    Hi Travis,

    Cool! Sounds like a great system and really quiet. Would love to see a pic once you are up and running…

    Paul

  • ptgibbs

    Hey Paul – best article on setting up DC I’ve read yet! I was also wondering how you configured the on/off system for your tools? Did you integrate the switches in your equipment? Do you have a remote? Paul

  • ptgibbs

    Hey Paul – best article on setting up DC I’ve read yet! I was also wondering how you configured the on/off system for your tools? Did you integrate the switches in your equipment? Do you have a remote? Paul

  • Paul Mayer

    Hi ptgibbs,

    Thanks for the feedback. I use a remote control that was provided as an accessory from Clear Vue Cyclones. I bought a few extra remotes and I have them mounted near all of my primary tools.

  • Paul Mayer

    Hi ptgibbs,

    Thanks for the feedback. I use a remote control that was provided as an accessory from Clear Vue Cyclones. I bought a few extra remotes and I have them mounted near all of my primary tools.

  • Chuck

    Paul, I am also about to set up a 6″ system. I looked thru your pics and text and don’t see anywhere where you have 6″ flex over PVC pipe, only inside PVC fittings. Does the flex not fit over the pipe? This would mean I will need a fitting (at least a coupling) everywhere I want to use flex hose. Any guidance would be appreciated. Thanks.

  • Chuck

    Paul, I am also about to set up a 6″ system. I looked thru your pics and text and don’t see anywhere where you have 6″ flex over PVC pipe, only inside PVC fittings. Does the flex not fit over the pipe? This would mean I will need a fitting (at least a coupling) everywhere I want to use flex hose. Any guidance would be appreciated. Thanks.

  • paul mayer

    Hi Chuck,

    Yes, you can get it over the top of PVC, but I like the flexibility of using the couplers because it provides a great quick disconnect system. If you have trouble slipping the flex tube over the PVC just cut some slits into the PVC as you see shown in the 2nd picture in this article. Then apply a band clamp to compress the PVC so that it will easily slip down into the flex tube. If it is still tight you can warm up the flex tube a bit with a heat gun.

  • paul mayer

    Hi Chuck,

    Yes, you can get it over the top of PVC, but I like the flexibility of using the couplers because it provides a great quick disconnect system. If you have trouble slipping the flex tube over the PVC just cut some slits into the PVC as you see shown in the 2nd picture in this article. Then apply a band clamp to compress the PVC so that it will easily slip down into the flex tube. If it is still tight you can warm up the flex tube a bit with a heat gun.

  • Chuck

    Thanks, Paul. I’m still flip-flopping over which piece of PVC (pipe or fitting) I want attached to the flex, based on what is going where in the shop and how much moving will happen. I am just finishing up my separator, so I will probably start running duct tomorrow, but that still gives me some time to decide before I start cutting pipes to length. How do you attach the flex inside the coupling?

  • Chuck

    Thanks, Paul. I’m still flip-flopping over which piece of PVC (pipe or fitting) I want attached to the flex, based on what is going where in the shop and how much moving will happen. I am just finishing up my separator, so I will probably start running duct tomorrow, but that still gives me some time to decide before I start cutting pipes to length. How do you attach the flex inside the coupling?

  • Paul Mayer

    Chuck,

    One option might be to attach a coupler, and then you would have multiple options to attach to that depending upon which tool you were using it on. You could configure a reducer and piece of 4″ flex hose for 4″ ports, and connect directly to the 6″ ports with the coupler.

    As far as attaching the flex pipe to the coupler, I just tuck it inside and there is enough friction to hold it on place. On the 4″ it is a bit looser, so I have used duct tape to secure it. Another way to do the quick disconnect is to use the bell connection at the end of the PVC pipe, rather than the coupler. In the second picture in the article, the green PVC is actually the bell coupler at the end of the pipe. I slip the PVC over the small end, and then the bell slips over the dust port on the tool. This approach provides enough friction to hold them solidly.

  • Paul Mayer

    Chuck,

    One option might be to attach a coupler, and then you would have multiple options to attach to that depending upon which tool you were using it on. You could configure a reducer and piece of 4″ flex hose for 4″ ports, and connect directly to the 6″ ports with the coupler.

    As far as attaching the flex pipe to the coupler, I just tuck it inside and there is enough friction to hold it on place. On the 4″ it is a bit looser, so I have used duct tape to secure it. Another way to do the quick disconnect is to use the bell connection at the end of the PVC pipe, rather than the coupler. In the second picture in the article, the green PVC is actually the bell coupler at the end of the pipe. I slip the PVC over the small end, and then the bell slips over the dust port on the tool. This approach provides enough friction to hold them solidly.

  • Chuck

    Paul, I just got around to trying a friction fit with the 6″ coupling and the flex. Geez, my machine tool teacher would call that an Interference Fit. I think this will definitely be the way to go.

    Ummm, any suggestions on getting the flex into the coupling? :-)

  • Chuck

    Paul, I just got around to trying a friction fit with the 6″ coupling and the flex. Geez, my machine tool teacher would call that an Interference Fit. I think this will definitely be the way to go.

    Ummm, any suggestions on getting the flex into the coupling? :-)

  • paul mayer

    Hi Chuck,

    Are you saying that it is a tight fit but it is difficult to slip the flex pipe into the coupler? Mine was not difficult to get in there. I just tucked one side in, and then reached through the other end of the coupler and pull the flex pipe into the coupler. If it is super tight I would cut a slit into the flex, cutting through a couple strands of the wire that wraps around it, and that should help you get it started. Once it is started hopefully it will slide the rest of the way in without a problem. If that doesn’t give you enough wiggle room you might need to either try different flex pipe that might have a different diameter. Another option would be to make your own coupler out of plywood or MDF. Or, use the bell end of the pipe as a coupler using the approach that I described previously. It’s not as quick as using the coupler, but it is not too bad.

  • paul mayer

    Hi Chuck,

    Are you saying that it is a tight fit but it is difficult to slip the flex pipe into the coupler? Mine was not difficult to get in there. I just tucked one side in, and then reached through the other end of the coupler and pull the flex pipe into the coupler. If it is super tight I would cut a slit into the flex, cutting through a couple strands of the wire that wraps around it, and that should help you get it started. Once it is started hopefully it will slide the rest of the way in without a problem. If that doesn’t give you enough wiggle room you might need to either try different flex pipe that might have a different diameter. Another option would be to make your own coupler out of plywood or MDF. Or, use the bell end of the pipe as a coupler using the approach that I described previously. It’s not as quick as using the coupler, but it is not too bad.

  • Chuck

    Paul – Yes, my flex is a very tight fit into the coupling. I have one bell end of pipe that I managed to get flex onto, though if I wanted it to connect more deeply I would have needed a heat gun. I did figure out how to help with the couplings – I remembered back thirty-#$%^#@& years ago and replacing the handlebar grips on my bicycle. Remove the old ones with a razor knife, then lube up the new ones with a little liquid dish soap. It’s slippery enough, and once it dries it’s stickier than using nothing. A win-win. Gonna give it a try in a day or two. SWMBO just returned from visiting relatives for a few weeks and giving up a little shop time this week should help me to maintain tranquility. Thanks for all your help this week.

  • Chuck

    Paul – Yes, my flex is a very tight fit into the coupling. I have one bell end of pipe that I managed to get flex onto, though if I wanted it to connect more deeply I would have needed a heat gun. I did figure out how to help with the couplings – I remembered back thirty-#$%^#@& years ago and replacing the handlebar grips on my bicycle. Remove the old ones with a razor knife, then lube up the new ones with a little liquid dish soap. It’s slippery enough, and once it dries it’s stickier than using nothing. A win-win. Gonna give it a try in a day or two. SWMBO just returned from visiting relatives for a few weeks and giving up a little shop time this week should help me to maintain tranquility. Thanks for all your help this week.

  • Paul Mayer

    The soap seems like a worthwhile trick to try. I’d be interested in hearing how it works.

  • Paul Mayer

    The soap seems like a worthwhile trick to try. I’d be interested in hearing how it works.

  • Chuck

    SWMBO first, soap… eventually. I will let you know, though.

  • Chuck

    SWMBO first, soap… eventually. I will let you know, though.

  • Paul Mayer

    Good call, Chuck. :)

  • Paul Mayer

    Good call, Chuck. :)

  • http://www.dust-extraction-systems.co.uk/ Dust Extraction

    I have never gotten a shock in 10 years of running PVC ducting in two
    different shops, so I have never bothered with grounding mine.

  • paul mayer

    Since upgrading to a more powerful dust collector I have gotten some minor shocks at the tools during the dry MN winter, but nothing to be concerned about. I did receive a major shock when I overfilled my plastic dust collector and ran it for a while before I realized it. All those wood shavings swirling in a plastic funnel was a wicked combination. When I reached out to touch it, the spark arched about 6″ and snapped quite loudly. So I wrapped a ground wire around the dust collector a couple times and grounded it. I have overfilled the dust collector a few times since, but no more shocks of that magnitude.