Another idea for shopmade blast gates

[zayd alle]

I meant to post about these years back when I made them, but clearing out shop reminded me that I never did. Yet another idea for shop made blast gates.

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Body:


1. I started by cutting a 6" PVC coupling in half. I did this on my 12" miter saw with a jig to hold it safely.
2. I cut PVC trim board (Azek is a common brand, available from the home centers) into body blanks -- two for each blast gate.
3. Using a fly cutter, I cut a hole to match the coupling OD in the body blanks.
4. Using PVC glue (sold by Azek also at the home centers), I glued the coupling halves into the blanks, one for each side, smooth side in.
5. I ripped thin pieces of Azek a hair over 3/16" to glue in as spacers between the body halves.
6. I assembled the halves using the spacers.


Gate: Just 3/16" hardboard cut to size and fly-cut for the 6" hole.


Ends: PVC cap material for the big 4'x8' sheets of PVC lattice at the home centers. They come in 8' lengths so one length of each color was all I needed for 6-8 gates. I chose different colors to be able to quickly tell open/close status. I slightly enlarged the slot of the caps at the table saw to fit over the 3/16" hardboard. A couple of drilled holes and screws attached them.


Tip: do your PVC cutting and drilling all together so you only have to go through that cleanup once. It clings to everything, but a shop vac helped here.


What I'd do differently: I put the factory ends of the couplings toward the inside so that I'd have clean transitions at the gate. But this meant I had to file the cut side slightly to fit my 6" PVC ducting, since the couplings have a very slight taper in the ID. I'd probably keep the factory ends out if I were to do it again.

[Allan Dozier]

Thanks. I like that idea of using PVC for the body so you can use PVC glue to attach the coupling. I'll be needing to make some soon.

[Bill Dufour]

I like the handle idea but I would only use one. Then you can pull the gate to clean any packed dust out of the slot easier. I like to draw a line on the slider when it is in the correct position for the gate to be wide open. that way i do not need the extra stop.
Bill

[Carl Kona]

Zayd,

Thanks for the post and the description. Is there a benefit or reason you used PVC vs. MDF for the body?

Thanks,

Carl

[zayd alle]

Thanks for the post and the description. Is there a benefit or reason you used PVC vs. MDF for the body?

Carl,

A few reasons. PVC is much more durable and unaffected by moisture swings (my shop is largely unconditioned). As Allan said, I could also glue the couplings directly into the PVC blanks without issue. I already knew I was using PVC for ducting, so it made sense to make PVC blast gates as well.

Bill, that is a consideration. Mine rarely required it though. I suppose I hit a nice sweet spot where the spacing was narrow enough to clear dust on its own with the open/close action but wide enough that the gate didn't stick. And pulling a handle off would have been quick anyway.

[Jim Dwight]

When I used a DC I had blast gates that were functionally equivalent to this but built mainly of plywood. I used half PVC couplings but bored holes in the plywood that were a tight fit for the half couplings. A little good caulk on the joint and it worked fine. I used a couple pieces of thin cardboard when I glued in the spacer for the slider and then a piece of the same plywood for the slider. I used everything from door skin plywood to about half inch for the slider and 1/2 or 3/4 for the body pieces. But the thickness isn't critical.

I used inexpensive plastic blast gates before I started making my own and they plugged with sawdust pretty quickly and wouldn't slide. I might have been able to install them different and get them to work but I think home made are better.