The ducting is finally in the shop. I’m determined to get this thing done by 24th of November (1 year from my move in date).
I’ve worked out a design to minimize the amount of ductwork I need. It wasn’t too easy due to the location of the cyclone (which was predetermined by space). I’ve got a main line with two wye branches coming off which supply the rest of the shop. All the ducting is 6″ right to the tools. I have lots of work to do on dust hoods, but I’ll do that on a tool by tool basis throughout the year. I just want to get the most used tools set up now.
Reading Bill Pentz, he recommends putting the blast gates as close to the main line as possible. In this case each branch supplies multiple tools, so I’d be killing an entire branch at a time (and I’d still have to have gates at each tool).
On one level this makes sense, as it minimizes the amount of pipe open to suction at any time. Minimizes the effect of leaks in unrelated parts of the system.
On the flip side, it seems like overkill. I can easily add 5 gates to my system this way… gates I may never use. It seems it may increase the chance that I may end up with no dust gates open. Further the dust is high, so I’d have to work out some system of opening them and closing them.
Replies
I have a gate at each tool and open/close them as I move around the shop. My system is 4" with an even mix of solid duct and flex duct. All seams in the solid duct was taped with electricians tape, as well as all joints.
My system works great - as long as I remember to close the gate of the last tool I used before firing up the next one. - lol
I've thought of doing some kind of "manifold" box near the DC with all the gates in one location and home runs to each tool. I doubt if I'll ever do that, however since it would probably take longer to switch from one tool tp the next.
Buster,
I have placed a blast gate at each tool as close as I could get to the tool. I would do the same again if I were starting over. The MUCH greater convenience overrides the reasoning for any other placement IMHO.
Best of luck with it!
Regards,
Mack
"Close enough for government work=measured with a micrometer, marked with chalk and cut with an axe"
Thanks guys. I'm wondering how much (if any) performance will be lost. My original plan was t pick up some cheap plastic gates. Then if I never used them I wasn't out anything. However cheap plastic gates are nowhere to be found in the city. I'm at the point now where I'd have to add at least one.I suspect that unless I get some responses saying YOU HAVE TO... Then I probably wont bother. I could always slide the sections apart later I guess.My wife is out tonight, so I'm watching the kids (they're already in bed), so I've got the night to think about it.Buster
Plastic ones probably wouldn't be much less than the Aluminum ones from the Blastgate Company.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
It's just a matter of finding the 6" blast gates locally. I'm tired of working on the shop, it's time to build! As well since I'm north of the border, I'd probably get dinged pretty hard on shipping.
All my usual suspects are out, the gates I bought are from Lee Valley (since I can just pick them up). But of course they're $16/gate. I bought 4, knowing I'd need a few more. In fact I need at least 4 more just for the tools, and if I block the branch runs an additional 3 ($48).
I'm thinking now I'll just leave a little flex in the system. Should I decide that the system will benefit from them, I'll add them later. The system itself is my 90% solution. I'm using regular HVAC fittings, due to their availability and cost. I figured the shop needs to 'season' a bit before I commit to anything truly expensive. I really need to invest some time in adjusting some of the dust hoods.
As others have stated... blast gate as close to the tool as possible. Use proper METALLIC Duct tape, not the el-cheepo cloth stuff. The metallic tape is a bit on the pricier side, but it works very well. It sticks like it has been contact cemented in place, and is flexible enough to neatly cover screws and pop rivets that were used to construct my system. I purchased it originally from MLCS (the router bit company) but I found it available at the local Home Despot.
SawdustSteve Long Island, NY
When I moved into my current house I went through and sealed all the seams that were open in the basement. The first day the AC turned on I thought the pipes might freeze down there.
I been using the stuff on all the joints and seems. On the advice from an HVAC buddy, any seams that may be under a little stress I run cover in the regular duct tape as well. His thought was that the aluminum tape rips to easily.
Any issues with the screws in the system? My buddy though they might catch material, but it's been my experience that most of the chips are fairly small. With the exception of plane shavings, that may get sucked up in the floor sweep. I've added a cleanout on the main run...
I used a combination of 1/4" sheet metal screws and pop rivets (the type used for rain gutters. I'm careful not to suck up any plastic bags as they COULD get hung up on the screws. I guess my hand-planing techniques are not that good as I don't get 6 foot long curls. The ones I produce go trhrough the system quite easily. Suspension from the ceiling was done with light-weight plumbers perforated strapping. A 100 foot roll goes a LONG way.
SawdustSteve
I've only got 4 gates and they're all at the branch points. No gates at the machines. This is for a primarily mobile base setup where tools get rolled out and connected to the drop lines. There's really not enough room to have more than 3 machines out and setup at the same time so there's only ever a single machine hooked up to a single drop at a time. So whichever machine has the power gets the duct opened for it's drop path back at the Wye. I do have to work 2 gates for two of the paths though as the first Wye has 1 side going to a 2nd Wye for 2 of the farthest duct runs.
If you build it he will come.
I have a penn state cyclone with( 6" dia. main and 4" branches) multiple gates for each tool. Once the gate is closed, it would seem that no air travels down that branch, so the placement of "close to branch vs. tool" wouldn't matter.
Although the gates aren't cheap (review Forest Girl's source), buy what you expect to need, since shipping isn't free either.
I have an Onieda Gorilla DC and 6" ducts going to the tools. I located my BG's near the tools. Yes, there may be some leakage along the way but so what? With 1 or 2 BGs open at a time there is more than enough vacuum and air flow at each open tool to handle everything including a 20" surface planer. I do have the planer located near the DC though.
The responses seems to be don't bother. So I didn't. No use in overanalysis. I was back in the shop last night and moved passed the point. There is enough wiggle in the system to add them later if I think I need to.
Thanks everybody for the responses.
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