Cheap dust collection wye's and connectors?

[Dave Rosner]

I've been working on my central dust collection design for some time. I've read the works of bill pentz and sandor nagyszalanczy as well as many posts on this and other sites. I've decided to play it safe and go with 26g steel ductwork and calculated a 5" main with a few 4" branches. The cost difference between the metal and pvc pipe isn't all that much - maybe $75 in my case.

That said, I'm getting really stuck on the wye connectors that I need to transitions from my horizontal main to The vertical branches that go to the machines from above. At $45 each the total cost of the system is going to get out of control fast. I have a 2hp collector and I'm really not worried about collapsing a cheap wye connector. Can I just use the cheap Home Depot HVAC connectors with my 26g pipes? A hvac wye looks to be less than $10.

Or is this a fools errand and you either go pvc and deal with it's issues or cough up the big bucks for the metal connectors?

[mike mcilroy]

I bought these 2 years ago at HD in MI.http://www.homedepot.com/p/Master-Fl...X6X6/202258555
I think back then the ones I got were 26 gauge. These are 28g. I've used a couple of 30g adjustable 90 degree bends and they've held up under a 3hp cyclone no problem. I think the concern about collapse is more for straight runs of pipe. These are crimped in the proper orientation for a DC system as well. Almost 18 bucks per, but still a huge savings. I went with the 6" mains it doesn't really add much to the ductwork price and you might want to upsize the system later. If not, I did see 5x4x3 wyes 28g same orientation listed when I copied that link tonight. I was more concerned about collapse on the 30g wyes because of the length of straight pipe on them. I figured the elbows have basically no straight run and each joint is almost reinforced because of the male/female shaped bends that allow them to fit together yet move but I also only used two of these because I ran out and figured I would try instead of crossing the border for 2 pieces. Hope this helps.

[Larry Frank]

The reason I went with 6" DWV PVC is the cost of fittings. I did a comparison of the total cost including fittings, pipe and blast gates. The PVC was significantly cheaper and I made my own blast gates.

[Brian W Smith]

We make our own,any size...any configuration.They're nicer because we really stretch out the transitions,keeps more velocity compared to typical reducers'.A 6 or 8" with a 4" wye,centered(no offset),takes maybe 15 minutes.Even though we still use a "few" slip fit,male female joints....they are in the decline.It's about as fast to make a rolled edge joint.And if it needs to be a serviceable joint,sleeves and compression clamps are "it".True pantleg wyes are still a challenge,but am getting faster,haha.

Best of luck with your project.

[glenn bradley]

The reason I went with 6" DWV PVC is the cost of fittings. I did a comparison of the total cost including fittings, pipe and blast gates. The PVC was significantly cheaper and I made my own blast gates.

Ditto. I would do a total cost estimate for both solutions and then decide. I would also just go ahead and go to 6" mains as opposed to potentially forklift upgrading the whole thing later.

[Alan Bienlein]

I made all of my own wye's using the free pipe joint template software at www.harderwoods.com .

[Jim Becker]

Yes, you can use HVAC wyes, but you'll need to modify them as they will be "backwards" relative to the crimps and flow direction. They are also available in 26 gage if you hit up a supply house.

[Jim Finn]

I did like Allen did. Make your own. But I am a former sheet metal worker. His link to the self made wyes gives you the approximate hole shape to be made in the pipe.

[Dave Rosner]

Appreciate the responses - very helpful.

The reason I'm going with 5" main over 6" is because the main will run across the old barn floor above my shop. I need to add a subfloor over that old floor so I can insulated my shop ceiling without losing height. The first floor is maybe 9 feet to the ceiling boards and the second floor is more than 20' high. Plus that second floor is probably dangerous. So I figure I need to use 2x6s for the subfloor joists and the 5" pipe is the largest I can fit.

Im still debating if I run the main along the walls of the 20x20 shop dying 6" instead. Same number of turns but quite a bit more straight pipe with that design....

[William C Rogers]

I have been using 30ga (wye's are 28ga) for over a year. I did testing on the 30ga fittings and pipe with my 3hp DC. I found the pipe would collapse without reinforcement, but the fittings did just fine. There was no distortion at all. Note I am not recommending either 26ga or 30ga, just posting what I have done. I ended up using 30ga for both fittings and pipe. To use the pipe I needed to put plywood rings midway of the pipe to keep it from collapsing. Also the wye's need to have the crimp reversed for DC use.I have been running this system for over a year with no problems. Initially I thought it might have been better to have purchased 26ga pipe (about a $100 more). However now i feel I would have spent $100 more with no increase in performance or benefit.

Here are are links to my testing and system

http://www.sawmillcreek.org/showthre...ing&highlight=

http://www.sawmillcreek.org/showthre...hop&highlight=

[glenn bradley]

While you're debating 5 inch versus 6 inch consider that a 6 inch will carry something like 30% more volume.

[Dave Rosner]

Dumb question - how do I reverse the crimp? I haven't worked with this ducting before but I get that one side of pipe and fittings get crimped. If the fittings come crimped on the wrong end then I have to get a crimping tool and crimp the proper end. But what do about the original crimped end? How do I "uncrimp" it?

and....does the crimp go on the side closer to the blower I assume?

[Jim Andrew]

You put the crimped end into the plain end, toward the collector, so that a chip of wood will not catch in the joint. You can "uncrimp" a fitting by using a hammer to flatten the crimps. Back up the fitting with a piece of heavy steel pipe.

[William C Rogers]

Dumb question - how do I reverse the crimp? I haven't worked with this ducting before but I get that one side of pipe and fittings get crimped. If the fittings come crimped on the wrong end then I have to get a crimping tool and crimp the proper end. But what do about the original crimped end? How do I "uncrimp" it?

and....does the crimp go on the side closer to the blower I assume?

you can get a hand crimper for about $20

[Jim Finn]

One way to un-crimp a duct is to just cut the crimp off. Another way is to add a short piece of duct with both ends not crimped. This second method may give you a little constriction though.