Questions for Delta 50-760 (or similar) DC users

[David Croteau]

I’m trying to get my little Delta DC hooked up to some basic ductwork in my 2-garage shop (short runs, minimum turns, etc) and am running into some dilemmas. Any thoughts from your experience?

1. Everything I’ve read in the archives suggests using 6” S&D PVC for the first part of a main line, even with a small DC like this. However, the port for the Delta is only 5” (or a double 4” wye). PVC isn’t available in 5” sizes, how can I do the transition from 5” to 6”?

2. Is there a way to go back down to 5” for machine ports or do I need to go down to 4”?

3. I have a lip from the block foundation (see diagram) that is a natural spot for me to attach much of the ductwork with minimal floor space loss. (I’ll go overhead for the TS out in the middle of the floor.) Is there any reason why I shouldn’t do this? Everyone seems to go overhead, so I’m wondering if I’m missing something.

Thanks!

[Bill Pentz]

I’m trying to get my little Delta DC hooked up to some basic ductwork in my 2-garage shop (short runs, minimum turns, etc) and am running into some dilemmas. Any thoughts from your experience? David, I have for more than six years been answering this same set of concerns from far too many who buy smaller cyclones and dust collectors. I just finished an email this morning from an engineer who has an identical unit to you. Here is what he asked and my response.


Bill, I am not a happy camper. I read your pages and the posts from the other air experts on the woodworking forums and followed your advice. I bought a new Delta 1.5 hp 1200 CFM dust collector. I tossed the wye with two 4” outlets and opened its 5” port to 6”. I carefully plumbed my shop with the all 6” metal HVAC duct you recommend from the local box store for those of us who do not have ready inexpensive sources of PVC. I went through the pain of cutting bigger holes in my tools to provide larger ports and remade the hoods. All worked like a champ for a couple of months then I noticed it was no longer collecting effectively from my Performax sander and I was getting piles in my mains that kept slamming around when they broke loose.

As an engineer I then bought a Dwyer Magnehelic gauge with pitot tube and followed your testing instructions on your Measurement page. My dust collector with no filter and a test pipe moves over 1200 CFM just like Delta promised, but with the filter off and just the longest run open to my planer about 12’ away, I’m only getting 640 CFM airflow. If I put the just cleaned filter back on my airflow drops to only 540 CFM. I know you recommend at least 800 and would prefer 1000 at our larger tools. What is going on?


It sounds like you did a great job on all we have to go through for good fine dust collection, except you listened to someone else's advice for your choice of collector and filtering. I do not recommend these sized dust collectors nor their fine bag type filters. In fact, I have been arguing against both, just as I have been trying to talk people out of undersized cyclones for more than six years.

The bottom line here is as your filter built up a cake of dust particles in the filter strands plus you added your ducting, you increased the resistance. I suspect if you measure the resistance of your ducting and filter, then look at a fan curve for your blower it is performing exactly as expected. This just is not enough blower for what you are asking it to drive to get more than good “chip collection” at these airflows. When it comes to picking up the fine dust, just as you learned the hard way, it just can’t move enough air. I take people through the steps to picking enough blower for their shops on my Deciding Needs web pages (http://billpentz.com/woodworking/cyclone/DecidingNeeds.cfm). I had similar problems with both my 1.5 hp dust collector and larger cyclone. I ended up changing my dust collector over to a portable unit with large fine cartridge filter and replacing my cyclone with one that had ample blower to drive my ducting and filters.



1. Everything I’ve read in the archives suggests using 6” S&D PVC for the first part of a main line, even with a small DC like this. However, the port for the Delta is only 5” (or a double 4” wye). PVC isn’t available in 5” sizes, how can I do the transition from 5” to 6”? With the prices of PVC soaring with energy costs, I often recommend people use steel duct. I like the NordFab, but the heavier 26-gauge snap lock pipe from the box stores works well. See my ducting pages for more detail. You probably should open your dust collector and replace its 5" port with a 6" HVAC flange. If you open your blower ports, do not run your dust collector without the ducting because you can move more air than you motor can support. Always verify with an amp meter that you are not hurting your motor.


2. Is there a way to go back down to 5” for machine ports or do I need to go down to 4”?Air at typical dust collection pressures is like water, virtually will not compress at all. Your small ports will hurt your airflow, but I am not sure your dust collector can support 6" ducting.


3. I have a lip from the block foundation (see diagram) that is a natural spot for me to attach much of the ductwork with minimal floor space loss. (I’ll go overhead for the TS out in the middle of the floor.) Is there any reason why I shouldn’t do this? Everyone seems to go overhead, so I’m wondering if I’m missing something.This is a great solution and saves the overhead of having long vertical runs. Most of us give too much away having to pull our equipment out from the walls to use your approach.


Thanks!

bill

[David Croteau]

Thanks, Bill. From having looked at your site, I know this is far from the ideal set-up. But I'm trying to make it work as best as I can for my modest needs without a major investment. I take the health issues seriously and am diligent about dust masks and open windows/doors whenever possible. Just now, though, I'm trying to tweak what I've already got to maximize my chip collection. Any ductwork is a step up for me since I've been wheeling my Delta around for a couple of years now.

[chris del]

I have the exact same Delta dc you have..... Ran a total of over 50' of 4" PVC piping to 4 machines (TS, jointer, BS and planer)
System works amazing, tonnes of suction even at the end of the line.
Can see why anyone would go the expense to use 6" pipe.
If I had a larger shop with a much larger DC I would consider it but not for a little 1.5hp 1200cfm unit....

My 50-760 is in the far right.... note the overhead line connected to the planner.


http://i75.photobucket.com/albums/i309/pickeringwoodworker/Picture384.jpg

[David Croteau]

Can see why anyone would go the expense to use 6" pipe.
If I had a larger shop with a much larger DC I would consider it but not for a little 1.5hp 1200cfm unit....


From Bill's site: "To get the needed 800 CFM that larger tools need for good fine dust collection through a 4" duct or hose you need about 9,000 FPM that takes a monster impeller and huge motor. That's why knowledgeable woodworkers use 6" ducts and 6" flex right to their larger machines even with portable dust collectors. Without a monster blower, if your duct is smaller than 6" to your larger machines, then it will not move enough air to capture the fine, most unhealthy dust."

Nice looking shop, Chris. Thanks for sharing your experience. That's exacty the sort of reality check I'm looking for. Sometimes I feel like the more I read, the more confusing it gets!

[chris del]

David......

I myself tend to reasearch things to death often never being satisfied with what I learn.....
My wife calls me MR Overkill as I tend to do things 10 times better and more costly than what they need to be.
I am not a engineer, so I dont care about CFM, static pressure or resistance. My system works using 4" and works well. Thats all I care about.
Good luck and be sure to ground plastic pipe (if you use it)

Thanks for the nice comment about my shop.

[Bill Pentz]

David and Chris,

Each of us has to make our own decisions on what is enough fine dust collection. With most dust related damage and health problems needing a few decades to appear, most never know what actually causes our problems when they appear and we often end up blaming smoking or something else. The medical research and forty years of insurance data is pretty clear that 100% of commercial woodworker are adversely affected but only about one in eight really seriously. The OSHA testing shows that since most of these shops blow their fine dust away outside unlike most small shop woodworkers, so we generally have higher fine dust exposures even when doing less woodworking.

Chris, I don't doubt at all that your system works like a champ. I was proud as punch of my Oneida-Air cyclone that I upgraded with finer filters, plus fancy looking ducting that used 4" down drops to all my larger tools. My shop stayed spotless with barely any fine dust on the tops of my tools. Who could argue with that? Unfortunately, I soon got to go to the hospital with fine dust triggered serious respiratory problems and found myself arguing with my new respiratory doctor, also a hobbyist woodworker. I took his challenge and a medical air quality test run on my shop. I ate a lot of crow because my clean looking shop was nothing but a false sense of security.

If I had just kept blowing out my shop well, all would have probably been fine. Instead, with that shop looking near perfect, the fine dust that the airflow to my tools missed collecting, plus the particles that went through my so called fine filter bags just kept building. My tools kept launching that previously made dust airborne and my body finally called time. Mine did earlier than most because of prior injuries, but the more I read and studied, the worse things looked. Wanting to protect my family and return to woodworking, I eventually upgraded. Doing so was a lot of work as much of what I had to do was not "common" knowlege and the parts were expensive.

Just my two cents worth.

bill

[Alan Tolchinsky]

I'm hearing you guys and that's why I don't trust ANY dust collector to get all the small most dangerous dust particles. I wear a respirator almost all the time when producing fine dust and always while sanding. Why take the chance with your lungs.

[Bill Pentz]

I'm hearing you guys and that's why I don't trust ANY dust collector to get all the small most dangerous dust particles. I wear a respirator almost all the time when producing fine dust and always while sanding. Why take the chance with your lungs.

Allan,

I fully agree with you and regularly wear a good mask when making fine dust, preferably working outside.

Unfortunately,one of my big upsets was learning what kicked my tail was previously made fine dust that my dust collection, tools, and air compressor launched while I was not making fine dust and not wearing my mask. If you have your dust collector or cyclone filters inside, then that residual dust either has to be gotten rid of, or we need to leave the mask on when working in the shop. Now I am so sensitive to wood dust I don't need a gauge or particle counter. Just a couple minutes in a friend's shop with a nice cyclone and I told him he needed new cartridge filters and I needed my asthma spray. We tested the pressure and sure enough his fine filters that were only about four months old were already shot. It turns out he had been cleaning them with his air compressor hose with the pressure far above the 40 pounds that most filter makers say is the max.

Additionally, with the fine dust spreading so quickly in shared air and so easily carried on our skin, clothes, and hair, unless we are collecting it at the source, we are probably contaminating our homes, vehicles and anywhere else we go while woodworking. That ends up with an even bigger problem because we get 24/7 exposure. For most woods that is probably not a big deal, but with cocobolo, walnut, rosewood, red cedar, and other woods known to be very irritating, this can be a big deal.

bill