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Way back, bulders recommended getting good quality vents for the instrument panel because some of the less expensive ones leaked air when they were closed. I picked up a pair of Wemac vents which are the SMOOTHEST pieces of hardware built by man. And if they leak then I can’t detect it with my sense of touch.
But they leak at speeds of 165 ktas and higher. You can’t feel it but hear it.
The vents create a Very LOUD high pitched buzzing sound, like a stall horn on 36 volts. The eyeball piece vibrates at a high frequency that makes a loud and alarming sound. I can’t feel any air leaking and no light is visible through the vent, but touching it lets you know its the culprit. The only things that stills the vibration is either slowing down or slightly opening the vent.
I have disassembled the vents, cleaned, and properly reassembled. I have tried sealing them to the panel with silicone. Neither made a difference.
Has anyone seen this before? Anyone know how to fix it? Stock NACA vents, Wemacs installed like the plans show.
Thanks
Andrew Anunson
Cozy MKIV #1273
Pound, VA
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My Cozy's vents don't squeal whistle or buzz but they sure make a lot of noise in the cockpit that messes with the intercom and COM audio. On someone's suggestion I tried stainless steel wool, scrubbing pads, stuffed in the vents. That seemed to help and didn't block much air. Try that, it may stop the resonance.
Del Schier
Cozy IV N197DL
Cannon Creek Airpark 15FL
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-----Original Message-----
From: canard-aviators@canardzone.groups.io <canard-aviators@canardzone.groups.io> On Behalf Of Andrew Anunson via groups.io
Sent: Wednesday, March 1, 2023 9:35 PM
To: Canard Aviators <canard-aviators@canardzone.groups.io>; Cozy Builders <cozy_builders@...>
Subject: [c-a] Vent Buzzing
Way back, bulders recommended getting good quality vents for the instrument panel because some of the less expensive ones leaked air when they were closed. I picked up a pair of Wemac vents which are the SMOOTHEST pieces of hardware built by man. And if they leak then I can’t detect it with my sense of touch.
But they leak at speeds of 165 ktas and higher. You can’t feel it but hear it.
The vents create a Very LOUD high pitched buzzing sound, like a stall horn on 36 volts. The eyeball piece vibrates at a high frequency that makes a loud and alarming sound. I can’t feel any air leaking and no light is visible through the vent, but touching it lets you know its the culprit. The only things that stills the vibration is either slowing down or slightly opening the vent.
I have disassembled the vents, cleaned, and properly reassembled. I have tried sealing them to the panel with silicone. Neither made a difference.
Has anyone seen this before? Anyone know how to fix it? Stock NACA vents, Wemacs installed like the plans show.
Thanks
Andrew Anunson
Cozy MKIV #1273
Pound, VA
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You sure it’s the vent? How are they installed? Scat tube, custom fiberglass tube? Where’s the inlet? I’ve heard of slot type leading edge inlets doing this.
Greg Norman
Way back, bulders recommended getting good quality vents for the instrument panel because some of the less expensive ones leaked air when they were closed. I picked up a pair of Wemac vents which are the SMOOTHEST pieces of hardware built by man. And if they leak then I can’t detect it with my sense of touch.
But they leak at speeds of 165 ktas and higher. You can’t feel it but hear it.
The vents create a Very LOUD high pitched buzzing sound, like a stall horn on 36 volts. The eyeball piece vibrates at a high frequency that makes a loud and alarming sound. I can’t feel any air leaking and no light is visible through the vent, but touching it lets you know its the culprit. The only things that stills the vibration is either slowing down or slightly opening the vent.
I have disassembled the vents, cleaned, and properly reassembled. I have tried sealing them to the panel with silicone. Neither made a difference.
Has anyone seen this before? Anyone know how to fix it? Stock NACA vents, Wemacs installed like the plans show.
Thanks
Andrew Anunson
Cozy MKIV #1273
Pound, VA
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I've always used the cheap, black eyeball vents. They're perfectly funcional, but they do leak some because the "flappers" are not a perfect fit. To solve that problem I wax the inside of the "tube, then lay up two layers of 4 oz. bid over the "flappers". to touch the inside of the tube. After that they don't leak at all. They don't make any weird noises either.
On Sat, Mar 4, 2023 at 8:29 AM Greg Norman < gnorm76@...> wrote: You sure it’s the vent? How are they installed? Scat tube, custom fiberglass tube? Where’s the inlet? I’ve heard of slot type leading edge inlets doing this.
Greg Norman Way back, bulders recommended getting good quality vents for the instrument panel because some of the less expensive ones leaked air when they were closed. I picked up a pair of Wemac vents which are the SMOOTHEST pieces of hardware built by man. And if they leak then I can’t detect it with my sense of touch.
But they leak at speeds of 165 ktas and higher. You can’t feel it but hear it.
The vents create a Very LOUD high pitched buzzing sound, like a stall horn on 36 volts. The eyeball piece vibrates at a high frequency that makes a loud and alarming sound. I can’t feel any air leaking and no light is visible through the vent, but touching it lets you know its the culprit. The only things that stills the vibration is either slowing down or slightly opening the vent.
I have disassembled the vents, cleaned, and properly reassembled. I have tried sealing them to the panel with silicone. Neither made a difference.
Has anyone seen this before? Anyone know how to fix it? Stock NACA vents, Wemacs installed like the plans show.
Thanks
Andrew Anunson
Cozy MKIV #1273
Pound, VA
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Scott Fish
Bob,
How do you trim the bid after it cures? Did you have to sand the flapper to get the epoxy to stick to it?
Scott
On Mar 4, 2023, at 8:05 PM, Bob Holliston <bob.holliston@...> wrote:
I've always used the cheap, black eyeball vents. They're perfectly funcional, but they do leak some because the "flappers" are not a perfect fit. To solve that problem I wax the inside of the "tube, then lay up two layers of 4 oz. bid over the "flappers". to touch the inside of the tube. After that they don't leak at all. They don't make any weird noises either. On Sat, Mar 4, 2023 at 8:29 AM Greg Norman < gnorm76@...> wrote: You sure it’s the vent? How are they installed? Scat tube, custom fiberglass tube? Where’s the inlet? I’ve heard of slot type leading edge inlets doing this.
Greg Norman Way back, bulders recommended getting good quality vents for the instrument panel because some of the less expensive ones leaked air when they were closed. I picked up a pair of Wemac vents which are the SMOOTHEST pieces of hardware built by man. And if they leak then I can’t detect it with my sense of touch.
But they leak at speeds of 165 ktas and higher. You can’t feel it but hear it.
The vents create a Very LOUD high pitched buzzing sound, like a stall horn on 36 volts. The eyeball piece vibrates at a high frequency that makes a loud and alarming sound. I can’t feel any air leaking and no light is visible through the vent, but touching it lets you know its the culprit. The only things that stills the vibration is either slowing down or slightly opening the vent.
I have disassembled the vents, cleaned, and properly reassembled. I have tried sealing them to the panel with silicone. Neither made a difference.
Has anyone seen this before? Anyone know how to fix it? Stock NACA vents, Wemacs installed like the plans show.
Thanks
Andrew Anunson
Cozy MKIV #1273
Pound, VA
-- <vent 1.jpg><vent 2.jpg>
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Scott, I sand the flapper (on the incoming side) with 80 grit glued to the end of a 3/8" dowel chucked op in an angle drill, takes about 2 minutes. I don't trim the bid. If it curls up a tiny bit onto the sides of the tube, that's OK.
On Sun, Mar 5, 2023 at 4:17 AM Scott Fish < scottbcs@...> wrote: Bob,
How do you trim the bid after it cures? Did you have to sand the flapper to get the epoxy to stick to it?
Scott
I've always used the cheap, black eyeball vents. They're perfectly funcional, but they do leak some because the "flappers" are not a perfect fit. To solve that problem I wax the inside of the "tube, then lay up two layers of 4 oz. bid over the "flappers". to touch the inside of the tube. After that they don't leak at all. They don't make any weird noises either. On Sat, Mar 4, 2023 at 8:29 AM Greg Norman < gnorm76@...> wrote: You sure it’s the vent? How are they installed? Scat tube, custom fiberglass tube? Where’s the inlet? I’ve heard of slot type leading edge inlets doing this.
Greg Norman Way back, bulders recommended getting good quality vents for the instrument panel because some of the less expensive ones leaked air when they were closed. I picked up a pair of Wemac vents which are the SMOOTHEST pieces of hardware built by man. And if they leak then I can’t detect it with my sense of touch.
But they leak at speeds of 165 ktas and higher. You can’t feel it but hear it.
The vents create a Very LOUD high pitched buzzing sound, like a stall horn on 36 volts. The eyeball piece vibrates at a high frequency that makes a loud and alarming sound. I can’t feel any air leaking and no light is visible through the vent, but touching it lets you know its the culprit. The only things that stills the vibration is either slowing down or slightly opening the vent.
I have disassembled the vents, cleaned, and properly reassembled. I have tried sealing them to the panel with silicone. Neither made a difference.
Has anyone seen this before? Anyone know how to fix it? Stock NACA vents, Wemacs installed like the plans show.
Thanks
Andrew Anunson
Cozy MKIV #1273
Pound, VA
-- <vent 1.jpg><vent 2.jpg>
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Scott Fish
Got it.
The leaks are no issue in summer, but when it’s cold (rare here in Central TX) I just tape over the outside of the NACA. Would prefer to just have them not leak…
Thanks,
Scott
On Mar 5, 2023, at 10:25 AM, Bob Holliston <bob.holliston@...> wrote:
Scott, I sand the flapper (on the incoming side) with 80 grit glued to the end of a 3/8" dowel chucked op in an angle drill, takes about 2 minutes. I don't trim the bid. If it curls up a tiny bit onto the sides of the tube, that's OK. On Sun, Mar 5, 2023 at 4:17 AM Scott Fish < scottbcs@...> wrote: Bob,
How do you trim the bid after it cures? Did you have to sand the flapper to get the epoxy to stick to it?
Scott
I've always used the cheap, black eyeball vents. They're perfectly funcional, but they do leak some because the "flappers" are not a perfect fit. To solve that problem I wax the inside of the "tube, then lay up two layers of 4 oz. bid over the "flappers". to touch the inside of the tube. After that they don't leak at all. They don't make any weird noises either. On Sat, Mar 4, 2023 at 8:29 AM Greg Norman < gnorm76@...> wrote: You sure it’s the vent? How are they installed? Scat tube, custom fiberglass tube? Where’s the inlet? I’ve heard of slot type leading edge inlets doing this.
Greg Norman Way back, bulders recommended getting good quality vents for the instrument panel because some of the less expensive ones leaked air when they were closed. I picked up a pair of Wemac vents which are the SMOOTHEST pieces of hardware built by man. And if they leak then I can’t detect it with my sense of touch.
But they leak at speeds of 165 ktas and higher. You can’t feel it but hear it.
The vents create a Very LOUD high pitched buzzing sound, like a stall horn on 36 volts. The eyeball piece vibrates at a high frequency that makes a loud and alarming sound. I can’t feel any air leaking and no light is visible through the vent, but touching it lets you know its the culprit. The only things that stills the vibration is either slowing down or slightly opening the vent.
I have disassembled the vents, cleaned, and properly reassembled. I have tried sealing them to the panel with silicone. Neither made a difference.
Has anyone seen this before? Anyone know how to fix it? Stock NACA vents, Wemacs installed like the plans show.
Thanks
Andrew Anunson
Cozy MKIV #1273
Pound, VA
-- <vent 1.jpg><vent 2.jpg>
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