Vent Tubes

[PilotMikeTX]

Alrighty! All done with the cleanup/restoration. There was some pitting and and scratches in the metal the spring button things were well rusted, so I didn't feel like leaving them naked so I powder coated them at the house. Also replaced all the toilet gaskets. Here are some before and after pictures.

[GAHorn]

Whooo-Hooo!

[170C]

PilotMikeTX, I don't know how you did he powder coating at home, but those sure look great. Wished mine looked that way. They looked a lot like yours did before you cleaned them up. I followed George's plan and got mine cleaned up, new felt and polished as much as they would do so. You could start yourself a small business since you can do powder coating on small items.

[PilotMikeTX]

I'd tell you my secrets, but I might need to get that business going since I've become a victim of the White House's "War on Corporate Aviation".

Powdercoating is actually really easy, and I've found that there are a lot of hobbyists who do it. Hot rodders and motorcycle folks mostly it seems.

That was actually my first attempt at it and it looks better than my best paint job. In fact I'm considering pulling my recently painted valve covers off and stripping them and hitting them with the powder. The best part is the overspray cleans up with the shop vac.

Oh, and my vents work great! I was hoping for no leaks, but I can only feel the smallest amount of air seeping out from the end where it should seal. It's certainly not blowing on my knee when its closed anymore.

[GAHorn]

I wouldn't blame the White House. I'd blame the stoopid auto execs and the media. (Besides it was congress that asked why they needed the money if they could ride around in jets.)

Ya gotta wonder how such stoopids came to be in charge of large coporations, ... if my brother came to my house in a limo to borrow money, I'd kick him out, even if I am a limo driver!

The crazy thing is, the public will not notice that the automakers will still run around in jets. They'll just charter from insiders instead. That's why Pentastar Aviaion was created back in the 80's. The recession at that time made Chrysler's flight dept look extravagant, so they spun it off into a separate profit-center.

[hilltop170]

Aviation takes another hit for whatever reason and the politicians still ride around in their tax-payer-paid jets!

[buzzlatka]

So I am getting ready to redo the vents and have a simple question that probably could be answered if I looked at the vents out at the hangar. Since I am in front of the computer I will ask. How do you remove the vents initially. When I pull them out to use them they seem to stop about three quarters of the way out. Do you just keep pulling a little harder or is there a trick.
Steve

[LBPilot82]

I also took George's advise and got some wool from a fabric store. Didn't have to come up with a clever excuse as to what it was for since nobody asked! I used some 3M adhesive spray with tape around where I didn't want any glue and it works like a charm. No more air leaks!!!

[GAHorn]

So I am getting ready to redo the vents and have a simple question that probably could be answered if I looked at the vents out at the hangar. Since I am in front of the computer I will ask. How do you remove the vents initially. When I pull them out to use them they seem to stop about three quarters of the way out. Do you just keep pulling a little harder or is there a trick.
Steve

When they get to the last of their open-position.... just wiggle-and-keep-puilling. They'll come out. YOu will see some small spring-loaded buttons that must be depressed to put them back in their outer-tubes when you're finished.

[buzzlatka]

Thats what I did, thanks. Those spring loaded buttons had corrosion and were a little sticky. I polished up the tubes and now will head out to the fabric store tomorow. The hardware store only had 1 1/4 inch wide. I need a little wider to make the circle dognut seal. I also have to clean out the inside of the tubes in the wing root.

[GAHorn]

Those vent-tube openings in the leading edge of the wing can be plugged with plastic dish-scrubbers to keep insects and mud-daubers out. If possible, get brightly-colored ones (off-brands) of a contrasting color, (red scrubbies on red airplanes don't stand-out) so they'll grab your attention during pre-flight. Of course, even if you forget them, no harm is done.

Get the extra-large ones for your sump-cooler opening and your cabin-air/heat openings. Tie a string to or thru them and a flag on the end of the string. This will allow the flag to drape out of your cowling, and the string is handy to pull the scrubby free during preflight.

Use upside-down "Dixie" cups (wax-paper cups) to stuff into your exhaust openings to keep moisture and insects out of your engine and mufflers. As your engine cools down after a flight, humid air is drawn into the cylinders of those which have stopped with an open exhaust valve. The cups prevent that. They also prevent mud-daubers from adding their restrictive-nests to your exhaust system. (Your closed throttle protects cyls with open intake valves.) The 3-oz. size cups work best in original tailpipes.

If you really feel motivated, a plastic scrubby with string can be stuffed up the carb-heat-exhaust of your airbox. I have personally witnessed the immediate aftermath of a Cessna's engine-failure on takeoff when mud-daubers built nests virtually overnight. Fortunately only minor injuries occured, but things could have been much worse, of course.

[HA]

hey George, you don'thave to ever bother to remove the potscrubbers, the air flows through just fine sans bugs of course. mine have been in there for about 20 yrs, 49 cents for the pair I remember.

when I redid my vent tubes, since there wasn't a fabric store within 100 miles (western ND is a little isolated) I used some felt wheel bearing seals that were laying around in the hangar. still working great, although the tubes can still blow open a tiny bit which won't bother you if you're in TX but can be a bit nippy in the winter up here. I'm still pondering solutions for a way to positively lock them closed without major mods or duct tape. but not pondering too hard, or I'd have fixed them by now, wouldn"t I.

[buzzlatka]

Used the weather seal for the main part but it was a little too thick. Had to trim it down with a razor blade. Used the real felt for the dognut seal. Worked great. If I did it over again I would just use the real felt for everything.

[Bruce Fenstermacher]

Just when I think I know about everything there is about the different 170 models I find something new. Well I've actually been looking right at this for quite some time but never put it together.

You see A models and '48s have a slightly different wing root vent tube. Actually the vent tube has one less part and it is a critical one if you want a good seal when the tube is closed. B model vent tubes have an extra cap in the end which has an additional felt seal.

This is the compete A model vent. Note no cap

A model vent tube.jpg (64.08 KiB) Viewed 10424 times

This is a B model vent tube. You can see the cap above the felt seal.

B model vent tube.jpeg (72.53 KiB) Viewed 10424 times

On the A model tube the felt seal donut which should be on the inside of the open end of the tube in the lip is much more critical. The B model tube also should have this seal.

I might have missed it but I don't believe any of these instructions address this felt seal. Has anyone made one? I imagine it's about 1/4" thick and so I have to find thicker felt to use to cut one out. Anyone have one of these felt seals that can post a picture of it so we can get an idea what we are trying to reproduce?

[GAHorn]

....I might have missed it but I don't believe any of these instructions address this felt seal. Has anyone made one? I imagine it's about 1/4" thick and so I have to find thicker felt to use to cut one out. Anyone have one of these felt seals that can post a picture of it so we can get an idea what we are trying to reproduce?

Perhaps you missed the downloadable "doc" file I attached to the first post in this thread, where I described the process?

Here's the pertinent section:



"...The lower seal will simply be cut about 1” wide by about 7 inches long. Shorten it as necessary when you wrap it around the tube. Make certain it completely surrounds the tube in order to make a complete seal. Then glue it in place with 3M brand 1300L adhesive or suitable substitute. ... After the adhesive is thoroughly dry hold the vent up to it’s receptacle tube and compare the felt thickness to the inside diameter of the receiving tube. You will probably have to remove some material to “thin” it down slightly, in order to get it to slide into the wing-root tube. This is easy to do with a wire wheel but can also be done with a hand-held wire brush. Don’t remove any more than absolutely necessary or the vent will not work properly. You want a fairly tight fit so the vent will remain closed by friction in flight against air pressure. It should be tight enough to require “wiggling” it into the wing-root tube. Remember to slightly depress the plungers to assist inserting the vent back into place...."

Of course, you could always simply order the seal from Cessna, PN 0413163-5, (supercedes to 0413163-43, for only $34.60 EACH ...plus tax and shipping.