How to Build a Dust Collection System
If there’s one thing I like. It’s breathing.
It’s just not healthy to be working in a woodworking shop that doesn’t have adequate dust collection in place so I decided I would build something for my shop. I’m going to walk you through the whole thing so that you know all the different components I used. Even though I know every shop is a little different, I think you can still apply the same ideas.
Let’s start off with the actual pipes that I installed for the dust collection. What you need is DWV grade 6 inch PVC which will be mounted to the ceiling and 4 inch to the walls.
Anybody can build a PVC pipe central dust collection system, it’s not a big deal. The pipe comes from Home Depot, Menards, or Lowe’s. It’s less than $10.00 for a 10 foot long section. Step one is to make a diagram so that you can identify the long runs and the fittings that you will need. You should lay out the connectors and pipe on the floor before you start hanging things on the walls and ceiling. You’ll notice that, for example, you will probably have a strange shaped fitting coming off the vertical pipe at the top that is called a Y. This is a normal drainage fitting and it comes down at a 45 degree angle and then goes into another 45 degree connector. This way 2 horizontal runs can be connected together. You might say why not just use 90 degree connectors. Well the reason is we’re trying not to slow down the air that’s being moved. If you force the airflow through a 90 degree turn instead of two gentler 45° turns you put more restriction in the system. You want to make the turns gentle as opposed to sharp. This means that you should use 90 degree wide radius sweeps also found near the drainage pipe fittings.
One of the other things you might think about is if you were doing plumbing work you would be using solvent cement on the pipes and fittings to bind them together and when you do it’s permanent. You want all of the joints to be press fitted. You just basically shove them together as tight as you can because it’s good enough for the airflow. Where you will run into problems is coming out of the straight pipes and trying to adapt them to the vacuum set up because the pipes are different sizes.
Now one other thing to be aware of is there are two different types of PVC pipe. DWV drainage weight is lighter with a thinner wall. If you go to the store and you find two different PVC pipes and they have different prices. Pick them up and the schedule 40 is a lot heavier. Leave that one behind. Use the drainage weight one. This is basically a thinner material and it’s going to be a lot less weight to move. The thickness of this wall and the diameter both interior and exterior makes it a challenge for fitting to a standard dust collection system. What you have to do is look for specific pieces that will work. A 6 inch splice will go right inside a flex pipe the challenge is how to secure it. The splice is actually made to work with flex tubing. You take the 6 inch Flex tube and you can stretch it around the outside of the pipe then you use a stainless steel worm gear type clamp. You’ve probably seen these before, it’s a little pipe connector that you put around the outside of the flex pipe, and then you just tighten a screw. Now they also make a thumb screw type which I prefer dramatically because you don’t need a screwdriver you just use your finger to tighten it up. They are made by several companies such as Ideal, Lokman, Hydrofarm, Hitichi, and Tech Team https://www.techteamproducts.com/. We liked Tech Team’s 6” Duct and Dust Collector Clamps https://www.amazon.com/Clamps-Phillips-Automtive-Tech-Team/dp/B07GZYRTHK/ref=sr_1_6?ie=UTF8&qid=1546285417&sr=8-6&keywords=6+clamps+duct because they have a 9/16” wire band and all the others are only ½”.
The heart of our dust collection system is a ¾ horse power vacuum set up. These are made with many different brand names. I don’t know if they’ll come out of the same factory or if they are actually different but we’re going to use a shop vac because it’s the one they had at the store I trusted. The way this thing works is there is an intake on one side and there is an exhaust that goes into a bag. The bag is only capable of filtering down to 20 microns. However things that go down to one micron or sub-micron can be really harmful for your lungs. An aftermarket bag that goes down to five microns is the right choice. You will feel a lot better about capturing the dust at five microns on the first pass. Now we’re going to use a cylindrical looking trash can as a particle trap. That’s because we’re going to convert what was otherwise a single stage system into a 2 stage system. But the theory is this. We plug in our machinery along the collection piping then the airflow runs first through the particle trap, and when it enters the trap gravity drops the heavier materials to the bottom. And that means we don’t have to empty the bag as often. We will use tees and elbows on the 6” trunk line to establish ports along the center of the shop so that we can collect the dust from the various table saws, jointers, planers, and sanders. Since the collector only has enough air volume to operate one port at a time we need to close off the ports not in use. For this we will use a valve called a blast gate which seals off a given port and allows the suction to go to the other ports. Each of the ports is connected to a 4 inch flex pipe with a 4 inch thumb screw type stainless steel clamp, the same type you would use on a clothes dryer vent. Once again we used Tech Team’s 4” stainless steel clamp because it uses a thumb screw/toggle to tighten the clamp https://www.amazon.com/Band-Style-Key-Style-Stainless-Collection Clothes/dp/B079RSJCJN/ref=sr_1_7?ie=UTF8&qid=1546285381&sr=87&keywords=dryer+vent+clamp This flex hose then connects to each woodworking machine. And bingo the whole thing has been connected to a four inch high volume dust collection system with a 6 inch main trunk.