# Blast gates



## Captspaulding (Dec 2, 2018)

So I've been moving my hose from one machine to another for a while. Thinking of something more permanent but realize I will lose some suction.

I have a simple jet 120v 1.5 hp with a separator. This is one level below my shop which is a dedicated 16×20. I will have one pipe go straight up into my woodshop with 1 split for table saw and misc small sanding. There will be another 16 foot run and straight up into the wood shop and this will split between my jointer, bandsaw and router table.

What's the best blast gate that tends to seal the best when closed?


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## wapakfred (Jul 29, 2011)

I would recommend shop built ones, but f you have to buy getting this kind would be better than this style. the reason why is the gate design. The one with the gate that slides all the way across the body won't have the dust build up problem that plagues the second one. On it the dust can gather in the back 2 corners where the gate slides in and prevent it from closing completely; thus it leaks. The are remedies, but why screw with them…just get some like the first ones (or build them yourself).


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## BattleRidge (Oct 22, 2017)

I went with 4" metal blast gates from Woodcraft, and they were a couple dollars cheaper then the Blast Gates at Rockler which appeared quite similar. I haven't messed around with them much to know about any leakage, though it appears to be minimal, at least compared to others at this price point.

I have a Grizzly G0548Z 2hp Dust Collector that is wyed into two lines of 4" PVC DWV (thin wall) pipe. One line has a blast gate at the end that is then wyed for the upper and lower dust ports for my Band Saw, and there is a wye midway in the pipe with a blast gate that runs to my Jointer. A second line has a blast gate at the end that runs to my Radial Arm Saw and there is a wye midway in the line that has a blast gate that is connected to a section of 4" flexible hose that I switch between my planer, table saw or other tools as needed. Basically my system is PVC pipe to the blast gates and 4" flexible hose from the blast gate to the machines.

Overall I have been trying to live within the budget and the two 4" lines were plumbed with PVC that I already had on hand from a previous project. I recently picked up a Super Dust Deputy (5" inlet / 6" outlet) at Woodcraft's scratch-and-dent sale for $25 (the box was damaged but the unit was in new condition) and would eventually like to upgrade my plumbing to 6" lines wyed off to the 4" blast gates and incorporate the Super Dust Deputy before the Grizzly, but the cost for 6" pipes and fittings are out of my budget at the present.

I typically only operate one machine at a time and will have the gate to the machine I am using fully open, and a second gate on the other line sometimes partially open to increase the overall flow rate through the system, and haven't been concerned as much about loss as I was about having sufficient flow volume (particularly with the 4" lines).

Depending on the projects I am working on and my work flow, I will at times leave the blast gates to two machines open to limit the delay of constantly opening and closing the units, and thus the reason I placed the individual machines I did on the individual line that I did, to have flow through each line simultaneously.

My dust collector has a 6" intake with a splitter to three 4" inlets, and my unused third inlet has a fixed cap on the end.

I am not an expert on the subject but I don't think that the leakage at the blast gates for your overall system should be a particularly critical concern, though can't say the same about the plastic or other gate options. If you had a smaller unit, I might be more worried, but I think that a 1-1/2 hp Jet should be a pretty capable unit. I'm not sure what you have for a separator or the effect that could have on the system though.


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## Captspaulding (Dec 2, 2018)

> I would recommend shop built ones, but f you have to buy getting this kind would be better than this style. the reason why is the gate design. The one with the gate that slides all the way across the body won t have the dust build up problem that plagues the second one. On it the dust can gather in the back 2 corners where the gate slides in and prevent it from closing completely; thus it leaks. The are remedies, but why screw with them…just get some like the first ones (or build them yourself).
> 
> - Fred Hargis


So I've seen many of the homemade ones. For the quantity I'm looking at the cost isn't a huge factor. Ironically I bought my collector used and I believe I got a tote with some of the bad gates you showed.

You suggest homemade ones, do you feel they perform better?


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## Captspaulding (Dec 2, 2018)

> I went with 4" metal blast gates from Woodcraft, and they were a couple dollars cheaper then the Blast Gates at Rockler which appeared quite similar. I haven t messed around with them much to know about any leakage, though it appears to be minimal, at least compared to others at this price point.
> 
> I have a Grizzly G0548Z 2hp Dust Collector that is wyed into two lines of 4" PVC DWV (thin wall) pipe. One line has a blast gate at the end that is then wyed for the upper and lower dust ports for my Band Saw, and there is a wye midway in the pipe with a blast gate that runs to my Jointer. A second line has a blast gate at the end that runs to my Radial Arm Saw and there is a wye midway in the line that has a blast gate that is connected to a section of 4" flexible hose that I switch between my planer, table saw or other tools as needed. Basically my system is PVC pipe to the blast gates and 4" flexible hose from the blast gate to the machines.
> 
> ...


My separator is homemade design. Two inlets over a 55 gallon plastic drum. Not sure if I loose any suction, but I'm thinking about 95-98% ends up in the drum.


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## wapakfred (Jul 29, 2011)

> You suggest homemade ones, do you feel they perform better?
> 
> - Captspaulding


Not necessarily, but maybe. If you build them your self, they'll will be a little cheaper and they might have a larger ID than the store bought ones. Most of the store bought 4" gates are really closer to 3 1/2" ID. Worse, the first one I linked above will have a small portion of the blast obstructing that smaller ID. Building 4" gates out of 4" PVC with the better gate design might give you more air flow, and will probably be easier to hook up to the 4" ductwork in the rest of your system (except the flex hose, it never seems to fit anything).


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## MikeDilday (Feb 21, 2017)

I would go with the metal blast gates. I have about a dozen and they seem to seal pretty good. If you are running down a wall make sure you get the gates that do not go out the back when closed.

These go out the back

https://www.amazon.com/POWERTEC-70135-4-Inch-Aluminum-Collector/dp/B00LPPF0S6/ref=sr_1_1?ie=UTF8&qid=1544395708&sr=8-1&keywords=blast+gate

These do not go out the back

https://www.amazon.com/Jet-JW1142-4-Inch-Aluminum-Blastgate/dp/B00005A1IV/ref=sr_1_5?ie=UTF8&qid=1544395708&sr=8-5&keywords=blast+gate


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## Lazyman (Aug 8, 2014)

I haven't made one yet, but when I do, this is the design I would use.


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## RobS888 (May 7, 2013)

> I would go with the metal blast gates. I have about a dozen and they seem to seal pretty good. If you are running down a wall make sure you get the gates that do not go out the back when closed.
> 
> These go out the back
> 
> ...


I have 4 of the powertec metal ones. no complaints at all.


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## Captspaulding (Dec 2, 2018)

I appreciate all the thoughtful replies and suggestions, probably have all the material to construct the blast gates including plastic sheet goods that should seal well. But not sure if I'd rather spend the time building them or not. I am about 3-4 projects to start after I finish the current one, and unfortunately I only have the weekends to spend in the shop. So I guess the time is more valuable in the long run.


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## MikeDilday (Feb 21, 2017)

The metal blast gates seal fine and they are not too expensive. I have never had one clog like the plastic gates do.


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## wapakfred (Jul 29, 2011)

> I appreciate all the thoughtful replies and suggestions, probably have all the material to construct the blast gates including plastic sheet goods that should seal well. But not sure if I d rather spend the time building them or not. I am about 3-4 projects to start after I finish the current one, and unfortunately I only have the weekends to spend in the shop. So I guess the time is more valuable in the long run.
> 
> - Captspaulding


Completely understandable. You can go back and redo the gates later if the ones you use aren't performing the way you want.


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## t3steve (Sep 14, 2018)

Those shop made pivoting gates are great, I going to build some.


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## MPython (Nov 30, 2018)

I built my blast gates form a design similar to the one Lazyman is considering. They work great. I've been using them for almost 8 years and have never had a moment's difficulty with them. I incorporated magnetic reed switches wired in parallel to activate a relay at the cyclone to turn it on and off when I open and close a blast gate. The switch is designed for home security systems and is used to trigger an alarm when a window or door is opened. They are very inexpensive, last forever and are simple to install. I used a thin sheet of PSA gasket material to seal the gate when it's open so there is zero pressure loss.


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## t3steve (Sep 14, 2018)

MPython do you have plans for your gates they look really well designed.


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## MPython (Nov 30, 2018)

> MPython do you have plans for your gates they look really well designed.
> 
> - t3steve


I don't have plans, but I have a spare gate. I would be happy to use it to make some drawings for you. I probably can't get to it until after the holidays. Let me know. 
The switches are actually "magnetic reed switches," not butterfly switches as I said in my post. I'll fix the post. Here is an Amazon link to them: https://www.amazon.com/Window-Contact-Security-Magnetic-Switch/dp/B07FFM93JG/ref=sr_1_28?s=security-surveillance&ie=UTF8&qid=1544547650&sr=1-28&keywords=magnetic+reed+switch

Hank


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## t3steve (Sep 14, 2018)

That would be very much appreciated, I am new to woodworking so working from plans is a lot easier for me that try to figure out the details myself.

Steve


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## MPython (Nov 30, 2018)

> That would be very much appreciated, I am new to woodworking so working from plans is a lot easier for me that try to figure out the details myself.
> 
> Steve
> 
> - t3steve


Steve, Check your messages.


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