There are many options for dust collection. There are some very expensive metal ducting options that are designed specifically for dust collection. There’s flexible hosing options too. And then there’s PVC. Every home improvement center on the planet sells PVC pipe! That seems like the way to go. Until you realize every woodworking store and website (Rockler, WoodCraft, etc) all sell PVC adapters for Schedule 20 PVC pipe, but that Home Depot and Lowe’s only sell Schedule 40 PVC pipe. The two are not compatible!
Where to Buy Schedule 20 PVC Pipe Locally
If you went online, or went to a local woodworking retailer and bought some PVC dust collection fittings (adapters), then you probably realized almost immediately afterwards that you couldn’t find any Schedule 20 PVC pipe. Probably right after you went to your local Home Depot, Lowe’s, and Ace Hardware only to be told “Schedule 20 doesn’t meet local plumbing code so we don’t sell it.” No kidding! In most areas of the country Schedule 20 is no longer allowed in new construction, or as a repair in older homes. The correct material to use is Schedule 40, but it costs in many cases twice as much as Schedule 20 pipe.
I recently faced this exact dilemma. Rockler sent me an entire dust collection system for the shop, but I couldn’t find any PVC pipe that it would connect to!
My Search to Find Schedule 20 PVC Pipe Locally
I looked in several places including my local big box stores. I also looked on-line. On-line was a giant waste of time (more-so than locally). PVC pipe in 4in x 10ft lengths was pretty affordable, but most came with minimum order quantities of 20 or more pipe and included shipping costs from $50 to $100 because it was too large for UPS to deliver.
I was in my local Home Depot and I ran into a really grumpy old sales guy who said “Schedule 20 doesn’t meet code! Don’t use that junk!” I let him know as nicely as I could that I was aware of that fact and that I was using it for a vacuum system in a wood shop. He had no idea what I was talking about, but after a few back and forths he said “You know, there’s an old feed store here in Keller up off of Johnson Road called McDonnell Hardware and Feed. I think I saw some Schedule 20 on their lot one time. I was almost in awe because I had driven by this place at least 100 times in my life and had no idea they sold more than feed for cattle. So I immediately headed there!
My Visit to McDonnell Hardware and Feed
McDonnell’s was a wild place. When I pulled into the parking lot it was like I went back in time 50 years. This place is like an old saloon that sells tools and home improvement stuff. And of course, farm equipment and cattle feed. As I walked inside there was an old man helping customers and some younger guys checking people out at the registers. They had quite the business going on!
I asked the old man if they sell Schedule 20 PVC pipe and he snarks back quickly in his very thick Texas accent “You don’t want that junk! It won’t pass code anymore.” I reply “I need it for a dust collection system in a wood shop.” He snaps back “Oh! Well that’s exactly the stuff you want! Walk this way.” He takes me back past shelf after shelf of tools and hardware items you would never find at a Home Depot and out into the yard. We walk past bin after bin of all kinds of different metal and plastic pipes, chain link fence, barbed wire fence, and then we stop. We stop at the mother load of Schedule 20 4″ PVC pipe! I could barely contain myself.
He looks at me and says “Here it is. Help yourself. Feel free to pull your truck around and load up. They are $6 each.” I say thanks. He then stops, turns around and says “Hey. I sell a ton of this stuff to pool companies all over the place. They like the cheap stuff. Keep any eye out if you ever build a pool.” Good to know! I loaded up on Schedule 20 4″x10′, and a ton of fittings and headed home.
Your Search for Schedule 20 PVC Pipe
You should be able to find Schedule 20 PVC pipe for your dust collection system at a plumbing supply house. If you don’t have one look for local farm store (note: Tractor Supply does not sell Schedule 20). Apparently you can also get some from your local pool company (frown).
Why not just use Schedule 40 PVC Pipe?
Many people ask, “Why not just use the better SCH 40 pipe for your dust collection system?” There are several problems with Schedule 40. First, it costs almost twice as much. And that makes sense because it is a lot stronger pipe. But even so it is overkill for a dust collection system. Second, and most importantly, all of the fittings these woodworking retailers are selling will not fit the diameter of schedule 40 pipe.
The long term solution in my mind is for these woodworking retailers to switch their adapters over to work with SCH40 pipe. Even though it costs more and is overkill for the purpose, it readily available at every home improvement center across the nation.
Safety warning: When using PVC pipe for dust collection it must be properly grounded. It represents a significant danger of static electricity build up which could result in fire or explosion.
I read your entire column hoping to find a place that sells adapters that take me from 4″ schedule 40 PVC to 4″ flexible dust collection hose. I agree the big box stores don’t sell anything I can use. I just ordered adapters from Woodcraft only to find they would only fit schedule 20. I’m sending them back Monday.
I too need to know where to find 4″ SCH20 PVC in near Rowlett TX area.
Yes, find a farm supply.
Good article, except grounding a PVC dust collector pipe is pointless. PVC is an insulator, so if you ground it in one point, the rest of the pipe will still be charged.
I’m not trying to be rude, but your statement means you don’t really understand the problem and why it is grounded. It has nothing to do with the material of the pipe.
It’s a myth…look it up. You can’t ground an insulator.
You don’t understand whats happening. You need to look it up. Science and physics do not care about the transport medium.
Ryan the whole “myth” that you don’t need to ground dust collection has been busted so many times its laughable! Stop posting fud! Static electricity is generated by the particles and air bouncing around inside the tube. This is exactly why the geek pub has screws that PENETRATE the plastic so they can absorb the static electricity INSIDE the tube. Please stop spreading fud!! It is very important to ground your dust collection system no matter what material your pipe is made of.
MYTH?????????? Facepalm. YOU ARE NOT GROUNDING THE PIPE anymore than a lightning rod grounds the house. You are giving the static electricity generated inside the pipe (same principle as a vandegraph) a place to go, rather than continuing to build up a larger and larger charge which can lead to a fire at worst, or a very nasty bite when you touch a tool at the least.
Hi Mike, you must live near Keller, or Watauga, I did live in Colleyville and I have been to Mcdonells several times over the years. I am now it Abilene:-) very few wood working sources here. I am having the same issue of connecting a supper dust deputy to my D.C. System,
here in Abilene you can find schedule 20 pvc at Bible Hardware. The tip on pool company’s is a good one too.
I agree with you on the static grounding on the pvc. I will say it for you.
To discharge the static build up spiral bare wire around the outside of the
Pvc pipe. Or you can run the wire on the inside of the pipe drill an exit hole for the wire seal it with RTV and ground one end of the wire. Static issue has been mitigated.
I need schedule 20 3″ PVC Pipe for an insect trap and I can’t find it anywhere. I live somewhat near Keller so I’m going to give McDonnell’s a call. Thanks for your post!
I used Sch 40 pvc pipe, all you need to do is use some adapters, aka Sleeves that are a 4″ OD, beause SCH 40 pipe is 4″ ID. and the hose will slide right on the sleeve. that was pretty easy to figure out after I bought 100 feet of PVC and 20 fittings, and the puny woodoworking fittings wouldn’t fit, easy fix.
Not sure if this works in every region, but try asking for “sewer and drain” pipe. I own a small hardware store in Maine where the thin-walled pipe is approved for exterior drainage and septic leech fields, but not for use inside a building.
In CA you can find this as sewer and drain pipe. Some big box stores carry it, but otherwise check with plumbing supply stores. I have used it extensively in my large home shop.
Another advantage is the thin wall PVC is easy to reshape to adapt to different size fittings and hoses. Heat it up with a torch or a heat gun. While the pipe is hot, use hose clamps to compress it or force it over the fitting. Saves lots of $$$ over premade adaptors. Check YouTube for tutorials.
Look in an electrical supply stores. One of the plumbing stores I called told me schedule 20 pipes are used as vacuum pipe or conduit in electrical applications. Sure enough my local store (Electrical Wholesalers in Framingham MA) had it in stock.
Lowes sells PVC schedule 20 and the fittings! They just don’t call it schedule 20. They call it sewer and drain piping. I went to two Lowes and they both had it near Charlotte, NC. I brought a dust collection fitting that I purchased from Woodcraft and it fit perfectly.
i NEED SCH 20 4′ x10′ VENT PIPE FOR MY VERTICAL PLANT ING TOWERS THERE WILL NOT BE ANY TRAFFIC OR WATER PRESSURE INVOLVED.
First, I admit that real-world tests win out over any speculation. So, I am curious if you have been able to test to see if the internal pipe accumulates static electricity after use, and that adding the metal screw solves the problem. Perhaps you can test a system with/without the screw, to know.
I don’t think that a grounded metal screw, even if it reaches the inside of the pipe is a solution. If the pipe is not electrically conductive, you will still accumulate static electric. Any internal arcing could potentially set the fine dust on fire.
But perhaps the screw could work if dust particles pick up the static electricity from earlier in the pipe, and then discharge it on the screw. Perhaps enough of that process happens, to keep the system at a low level of static charge.
I wonder if occasionally using an anti-static spray, and allowing the vacuum to suck some spray into itself may also be a potential solution.
I was able to find the 4” sewer and drain pipe at Mills FleetFarm. They carry both green and white which are not the same. The green is the one I found that worked with my blast gates and dust collection fittings. The green is spec SDR355, the white is ASTMD2729, the green has the thicker wall and will gives the fittings a nice snug fit. OD is the same on each
Great story, another reason those independent, old time hardware stores are where we should spend our cash first, before Lowes/HomeDot/etc. I’d add a plus one to the above comments about finding Schedule 20 in those electrical supply companies, who often sell at fair prices. I’m on the other side of the country on a heavily wooded lot where leaf matter enjoys clogging gutters, which need to be cleaned 20+ times a year. Twenty foot of 2″OD Central Vacuum Schedule 20 hooked up to a 6HP 2″ shop vacuum cleans all gutters in less than 20 minutes. Schedule 20 is key because twenty foot of Schedule 40 would be far too heavy to walk around with. Also, these are good reasons to give those small forgotten stores our business; the little guy who the big box stores have not yet put out of business.