# Dust collection host/duct/connection questions



## tfenne (Oct 7, 2011)

I've been lurking for a while now, mostly learning by reading existing posts on LJ, but I'm struggling with making some decisions about dust collection. Long story short I've read a ton of the information online and scared myself half to death about fine dust in the workshop and the damage it can do to your lungs. And since my shop is in the basement of my house, I could presumably be contaminating my whole house!

So I broke out my credit card and went shopping. Arriving in the next couple of days I have:
- a 3M 7500 series respirator with P100 filters
- a JDS air filtration unit
- a PSI 1.5HP dust collector with 1 micron canister

What I'm having hard time figuring out is the practical differences in how to connect the dust collector up to my table saw - my primary dust generator. I can position the dust collector about eight feet from the dust port on the table saw, which seems good. The collector has (much like most < 2HP connectors I've looked at) a single 6" inlet with a 2×4" wye attached. The table saw has a 4" dust port. Now for some questions!

1) A lot of literature seems to say that you need 6" duct/hose in order to have enough airflow to capture most of the fine dust. Given my collector and a single 8' run will I need 6" runs?
2) Is there any point to 6" runs if I don't upgrade the port on my table saw?
3) Any advice on what parts to use and where to find them to upgrade the port on my table saw to 6"? I've got a grizzly G0691 and it seems like I'd have to manufacture the port and cut a metal plate to open things up a bit…
4) Are metal ducts that much superior to pvc ducts and/or good flex hose?
5) Is it ok to mix flex hose with metal parts? E.g. the only 6" to 4" reducers I've been able to find are metal, so if I wanted to run 6" flex hose to the table saw and then reduce to 4" it seems like I'd have to mix

I guess all of the above really sums up to: I've bought what I think is a reasonable collector and have a short run to a table saw with a 4" port, what's the best way to connect the two without spending more than about $100 on connectors and host/ducts.

Chances are that I'll end up with more machines needing dust collection in the near future, but I'm only an occasional woodworking and don't see any problems with disconnecting the DC and moving it between tools as I need it.

Any and all advice gratefully received! Thanks,

-t


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## gfadvm (Jan 13, 2011)

With the short run you have the 4" should be fine. I don't have any 6" runs and I even have some 2 1/2 " runs which all function fine. I have mixed corrugated and PVC plumbing even though corrugated does decrease flow. Hope this helps.


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## LepelstatCrafts (Jan 16, 2011)

I went to the big box store and got some 4" out door black drainage pip. A few self taping screws 90 degrees to each other and everything is now hooked together. No problems with fine dust or the valleys stopping dust from being collected.


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## redryder (Nov 28, 2009)

*Long story short I've read a ton of the information online and scared myself half to death about fine dust in the workshop and the damage it can do to your lungs. *
I don't mean to come off too snarky but maybe you should take up another hobby. If your that worried about dust, go shake out one of your blankets and see what you get…...........


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## pete57 (Jan 22, 2009)

I build computer clean rooms at times and I know for a fact that you or no one else can get rid of dust. You can achieve a high level of CFM's, suction, and airflow, but you are going to have dust. Feel good that you are doing something about it. I usually open the garage doors and cut on a fan when cutting boards. I use an expensive dust mask when turning and basically building chairs is dust free. hand tools are fun for me right now.


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## ChefHDAN (Aug 7, 2010)

tfenne - Keep in mind that the risk is also compounded by the exposure, most of the facts/data is collected from industry and not exactly hobbists. In my modest opinion, a good DC and the JDS is an excellent step to protect yourself while working, and the respirator will be on hand for exceptionaly dusty tasks when you can't connect the DC to the tool.


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## topcat (Oct 2, 2011)

tfenne,
Not to minimize the negative effects of dust, but have fun. The fact is, none of us are making it out alive and while dust collection is important, the main point is don't worry. The dust is a part of the experience


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## tfenne (Oct 7, 2011)

gfadvm, Mike, pete57, ChefHDAN: thanks for the advice. It sounds like perhaps I should just start out with a short section of 4" hose or pvc duct and see how things go. I'm looking forward to a much less dusty basement 

redryder: perhaps I overstated the case - what I was trying to say was that I've read up a lot and have decided to take dust control seriously. From what I've read not all dust is created equal - most household dust is simply dead skin, something our lungs have presumably learnt to deal with over time, whereas fine wood dust can be far more damaging.


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## tfenne (Oct 7, 2011)

topcat: Thanks, and that's very true. On the other hand I'm only in my 30s and had respiratory problems as a kid, so I figure it's only sensible to control the amount of fine dust I'm breathing in in the workshop. The bigger stuff that's all over the floor isn't so much of a concern.


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## Cosmicsniper (Oct 2, 2009)

I think that more important than a single 6" port on the table saw is the ability to bring a second, smaller port at the blade guard itself. Most of the dust that concerns me on the table saw is the stuff that flies up…and even a 6" port might not capture that.

The ideal is 6" however. But in the case of a machine with only a 4" port, you will still see a benefit to keeping your main at 6" since it will improve overall static pressure. From there, you can determine the drop to each machine…and those ports you can't easily alter you can decide, at that point, to use 4".

If you run 4" straight from the DC, you lose the opportunity to do 6" at some machines. And make no mistake, the math shows that you won't capture all the fine dust at 4". At that point, it is up to the user to decide how much dust is too much. An efficient system at 4" coupled with secondary air purifier/filter might be just fine for you. It's certainly a highly individual thing…some people are more affected than others. People can work in coal mines, do wood working, and eat nothing but bacon all their lives and still live comfortably to 100. Others might dig an early grave.

I'd run a 6" main with a 4" drop to the TS and then make the decision from there whether it's good enough.


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## Cosmicsniper (Oct 2, 2009)

BTW, 5" ducting is better than 4". You have to use HVAC ducting for this, but it's probably worth it. Keep in mind that a 1.5 hp DC is right at the limit of being able to run 6" duct while maintaining enough velocity to still move larger chips. If you try it, you will certainly want to optimize your duct efficiency as much as possible, meaning good connections/transitions, gentle turns, and smooth ducts.


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## LeeBarker (Aug 6, 2010)

I think the tablesaw is pretty easy to control. Suck from the bottom and wear a mask, just a disposable is fine.

I'd work harder at controlling sanding dust, and for that I highly recommend a sanding table. There are kits that furnish the prewired guts and you just build the wood parts and install furnace filters. Well worth it!

DC is pretty easy to add to as you go. And while there are artistic setups out there, most of us have pieced them together with found stuff. Since it's suction, it's easy to seal up. Your highest planning efforts should go to placement of blast gates so it's easy to maximize the power to a specific site.

Kindly,

Lee


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