standard metal round duct work fits more cheaper..

 

Yeah, but it doesn't taste as good! :smile:

 

@johnyyB60

Welcome to the sad world of dust collection fittings. In contrast to plumbing where a 4" pipe is a 4" pipe regardless of where you buy it, in the world of DC, it is entirely dependent on the manufacturer. Perhaps it has to do with the abbreviation, "DC", as in Washington DC where nothing fits which gives us fits. Sorry couldn't resist that one.

Stick's point is well taken as with metal duct work you move back into the real world. However, you still have to pick the end fittings that mate to your devices. So, it is a headache but if you find a mfg that fits then stick with it.

 

Well in this case metal duct work will not solve the poorly made blast gate that does not close all the way and I have 6 more just like it.
I've been complaining for along time that I thought my system wasn't sucking all that well as the very first one I installed. It kept getting worst as I added more blast gates.

 

metal blast gates will tie/fit/couple right into metal duct...

 

I can't afford the metal ones. My system is large enough it needs that extra air for make-up air in the ducts. If I open one 4" gate, I need to open another in the same line to get maximum suction.
Herb

 

Herb, I kind of remember someone else mentioning something similar except I don't remember the details. I was just thinking that maybe there is some thought into preventing the blasts gates from closing all the way.

I have to say that after I plugged all the blast gates with pudding cups except for my Table Saw, I could hear the difference in air flow through the table saw insert.

 

Actually I do have one metal blast gate on my jointer and I know that it closes all the way, but I’m really not sure how well it seals because it’s a little sloppy. I bought a couple more metal one and haven’t installed them yet

I really love my 4” ABS drain pipe because everything fits to it real tight and there is a lot readily available locally except for the adaptor fittings. I will never change to metal.

 

have you got your system's air flow restricted... WHEW!!!
you need to go back and read the PDF's on how to design a system...
better metal gates seal well...

and what in blue blazes is that conglomeration in the 1st picture...

 

Oh I don't have a lot of room in my shop so i have my joiner under one wing of my table saw which I really love and my planner on wheels with flex hose to pull out when needed. Each has its own blast gate so I can open and close which ever tool I want to use.

 

I can cure your plastic blast gate problem.
I had the same problem and worked out a cure.

The sawdust collects in the sliding plate grooves, and every time you close the gate, you compact the dust into the bottom corners, eventually stopping the gate from closing.
I got fed up with having to dismantle the system and using a bent piece of wire to hook out the dust every time.

So take a small saw and cut the corners off of the ends of the top cover. like in this picture.

This has two benefits.
First, each time you close the gate the dust gets pushed out and you never have a sticking gate again.
second, if the pipe blocks anywhere, this produces a high pitched warning whistle so you know somethings gone wrong.

There is a very minor air leak obviously, but not enough to stop any system working properly

I showed this to my supplier, and he said he would talk to the manufacturers to try to get something done. But dont hold your breath for that one.

 

Bob, when I first started this thread, I was hoping for an answer such as yours. Thanks!

I was thinking about drilling holes, but then I thought maybe this is a fat as the door goes when I noticed all the plastic blast gates had the same problem. I am going to give this a try thanks again.

 

Blast doors can be designed better that current offerings, that is for sure.

 

Had the same problem with some cheap metal blast gates getting sawdust down in the slot preventing full closure. Found these from Lee Valley and they really do self clean and seal very well. Then even have a small tension knob to keep them from creeping open/closed, but I don't know that that has ever been a problem. An interesting solution to an annoying problem.
Self-Cleaning Blast Gates - Lee Valley Tools
My only criticism is the cuff for attaching the hose or fittings is a little short.
Mike

 

Thanks Mike, this is exactly what I have on my Jointer and it doesn't appear to have any problems, The only thing I don't like is having to bend over to tighten the screw to keep the door open every time I want to use it. Its more of a nuisance than anything, but i can live with it.

 

The "self cleaning" plastic blast gates from Woodcraft(and others) work great for me and they are only a couple of bucks more. The track never gets dust in it because there is always a part of the slide in it.

Buy Dust Collection Fitting, Self Clearing Blast Gate, ABS, 4-inch OD at Woodcraft.com JimE

 

What flavor pudding works best?

HJ

 

I like tapioca John, :grin::grin:

 

When i first noticed this problem, I didnt want to keep stripping out all the gates to check them. (I have 5 plastic gates) So I used a blue magic marker pen and scribbled a long blue line across the slide with the gate open. Then closed the gate tight, and removed all the visible blue marker.

then, as the gate started to jam, the blue line became visible. When the blue line was a solid 1/4" showing, the gate no longer sealed, so then I had to strip it.
But damn I'm lazy. i just felt I shouldnt have to be doing this, and thats when I cut the corners off.

This pic shows how far the gate had jammed open the first time i realised I had a problem.
Multiply that gap by 4 gates, and the system wasnt working at all.

 

This must be a royal pain in the derriere.

If you were to alter the orientation of the gates from vertical to horizontal (if that's possible???) would that help at all?

Do you remember those office messaging systems that used the tubes to carry a container from one place to another? How did they keep the air from leaking? Admittedly it has been a few years since I saw one of those, but they definitely worked.

 

I read about rotating the gate orientation to stop the dust being jammed in the grooves. I moved them all, and it made not the slightest difference. up, down, sideways, they all jammed.

The old messaging systems didnt jam cos they didnt have to contend with massive quantities of dust.

 

I use quality metal gate to very cheap plastic gates and all quality in between. Some of my plastic gates stick, some fall, some fall and stick, some just wont stay where I put them at all. They look very similar to what you are showing. Nothing I did ever fixed them, I got tired of it and started replacing them all one by one as they started to fail. This happened mostly to the thin plastic type of gates I purchased 10 and 15 years ago from various place like Peaches, Rockler etc. Its possible you just cant fix them, it drove me nuts.

 

my fix IS a fix. its permanent and works.
I wasnt prepared to spend loads of money replacing them all.
Of course the gates may eventually fail, but i would think I would wear out before they do.

 

The plastic ones I bought from Peachtree Woodworking slide all the way to where they bend for the handle (in the full closed position)... I've had no issues with these clogging, so far.... If they fail to "click" when closed at some point, I'll know they're up for cleaning....
There's no brand name on 'em, so don't know who the maker is.... The part number is 398 ....They're very thick plastic, and married perfectly to the stove pipe I used for the system....

 

I often have to eat a whole box full of icecream just so I can use the box to keep stuff in, hard work but someone has to do it. N

 

Anyone doing or contemplating building a dust Collection System will soon find that everything in this thread is true. I ended up with enough fittings to do another system after installing mine. This was the second time too. Nothing fits, there is no standard. 4" can mean inside or outside, or 3 7/8" or 4 1/4". All flex hose is not equal either.

Thank goodness for coffee cans and stove pipe. I took snaplock stove pipe and cut short pieces and pop riveted them together the right diameter.

Some coffee cans work too, some of the neoprene no-hub cast iron pipe connectors work too.
The best blastgates I have are made by Clear View Cyclone Company. They cost around $16. and handmade from clear acrylic. they have a small hole in the corners to suck air in and keep them clean like was suggested above. Trouble is the only come in 6" diameter.

A person just has to use their head and figure out the best way to hook things together.

Herb

 

Johnny,
I mounted mine sideways and then they do not creep and I don't have to use the tension screw. Is that a possibility on your jointer?
Mike

 

Mike, I guess the vibration has a lot to do with, but it’s so loose that I have to hold it up just to tighten it. I probably should have turned it sideways.

I converted the jointer to dust collection by making a sheet metal pan.

I originally tried a plastic blast gate, but had some problems and I don’t remember now what they were.

But the metal one fit a whole lot better

Only problem was that I had to add an elbow because the cross bar for the wheels was in the way.

 

Some good ideas in this thread.

There are a number of plans out there to make your own BGs. They all seem to be the open bottom type that don't clog with dust. Anyone ever made one? I like the idea that you can pick your pipe size(s) for the fittings.