When folks are replacing the rear windows in Cessna 170/172/180/182..... type aircraft:

1. What are you using to waterproof them? My 170 will be outside in the rain so I'd rather not develop a leak.
I was thinking of butyl tape as a gasket to seal things up.

2. Screws or rivets? Mine is bare metal so paint isnt an issue. Should I just put the 3/32 rivets back in or is there benefit to screws?
One thing with screws is I could tighten it up over time to squeeze out the butyl rubber if I go that route.

These are the thicker panels from Great Lakes Aero.

tks

Replaced mine in a 172 over 10 years ago, no leaks yet and parked outside all year long. I used rivets and a rubber "C" channel from Aircraft Spruce. Don't remember the exact size of the channel, but I measured the old channel when I took it out and matched it.

Just did both rear windows and the forward ones as well with blister windows. Its early days yet but the u-channel from Spruce worked well, easy to shape as required. I used rivets again but your idea of screws has merit and worth considering next time. Just please DON'T do what the previous "rocket scientist" did on my 170 SILICONE jeepers creeper what a mess !!!!

We use the rivets on reassembly. Fills the holes properly and keeps them nice and tight. For sealing we use a window sealant from the local window shop. Put tape on the window where the sealant will come to, between 1/8-"1/4" in from the frame. Also put tape around the outside of the frame. Apply sealant, smooth with finger, remove tape.
Agree with maple, dont use silicone.
David

Ouch... Do NOT use fasteners for windows. Tell tale sign of a hack job for sure. LOL Take your time and buck the rivets.

RE: sealant. As has been said, do NOT use silicone. I use 3M Strip-Calk to bed the plexi. For the side windows, this should be enough to keep things dry. Its watertight and permanently playable. https://www.amazon.com/3M-08578-Black-Strip-Calk/dp/B000PEZ1L4/ref=sr_1_2?ie=UTF8&qid=1528292837&sr=8-2&keywords=3m+strip+caulk&dpID=41Q%252BZ6kHPjL&preST=_SX300_QL70_&dpSrc=srch

If you want to really do it right, you can use a polysulfide sealant like ProSeal on the outside. Run some fineline tape around the OD/ID and then apply. Pull the tape off for a nice finish. http://www.aircraftspruce.com/catalog/appages/ps890.php?gclid=Cj0KCQjwjN7YBRCOARIsAFCb936N7xtVg4s_svmBx03FiqkJq8SE09xMcMNEPKuKzZutcYLMfizj9asaAsrbEALw_wcB

3M Strip-Calk is butyl rubber which is what I was thinking about anyway (+1 vote for butyl rubber). If you bed it right, it will fill the gap and ooze out a little. It rolls off with your thumb easy enough leaving a water tight seal to the edge and never gets brittle.
I bought a bunch of the stuff for the lower windscreen attachment.

The reason I asked about screws or rivets is some folks think it's easier to replace a broken window later on. Specially if the plane is painted (not over the screws). But I think rivets in where rivets were is a good general philosophy.

Thanks everyone.

[quote="Bagarre"The reason I asked about screws....[/quote]

LOL. You are doing some of the nicest (and correct) work on your bird around . When I saw you suggested screws I about fell over. Hahahaha

I apologize in advance because it seems like I should already know this. What’s wrong with screws for attaching windows? That’s how it was done on my Luscombe so that’s how we did it on the Bearhawk. There was a couple places we needed to use rivets on the BH windows but while installing the rivets we broke the window. Since I have to remake the window I’d like to install it using best practices.

I dont really know anything about the Luscombe. I would be curious as to know if that's how they did it from the fatory, or that's how it was done by the previous mechanic.

In Cessna's, it was done with rivets. Im a bit of a snob so take it with a grain of salt, but when I see Cessnas with screws in the windows it tells me a lot about the quality of work to expect. LOL

As far as plexi, I would recommend going with thicker glass. Great Lakes sells a better option than stock.

I got the thicker windows from Great Lakes along with 4" bubbles in the doors and thicker strapless windscreen.

The windscreen lower will be put in with screws mostly because enough holes in the fairing are already sized up from the last installer
I made up aluminum strips with floating nutplates to make it an easier job and not wreck the boot cowl I just put on.

I don't think screws in the side windows implies poor workmanship unless they are painted over. I hate seeing painted over removable hardware.

I should say that my comment on use of screws is for side windows and skylights, not windscreens. Side windows are a no-no, but thats just me.

I installed the four inch blister windows in my 170B this Winter; they are a great addition, second only to the baggage door !!

Mapleflt

We have replaced all of the windows in several Cessnas with a 3m product recommended by Kenmore Air. I can’t remember the exact product number and would suggest that you call them and ask. It has to be just the one specific number and there are other 3m products that are close and will not work at all. The stuff they recommend is awesome and hasn’t had a single leak that I know of. Sorry I can’t remember but do give them a call, they are super helpful.

This is what I use. Works great as well. I use electrical tape instead of fine line because it basically does the same thing for a lot less money. It allows you to follow bends and contours pretty easily.
I like that link you provided Greg. Thanks, I'll get some of that for when I do all my 206 glass.

Bigrenna wrote:I dont really know anything about the Luscombe. I would be curious as to know if that's how they did it from the fatory, or that's how it was done by the previous mechanic.

In Cessna's, it was done with rivets. Im a bit of a snob so take it with a grain of salt, but when I see Cessnas with screws in the windows it tells me a lot about the quality of work to expect. LOL

I haven't been about to dig out my Luscombe parts manual so I don't not for sure how they installed the rear windows. I can say for sure that the factory used screws to install the skylight.

So, installing the windows with screws isn't necessarily inferior. It just isn't original. ?

Thanks to everyone. I went the butyl tape route.

1st try, I used some 1" wide gray which looked terrible. It didn't fill the whole gap and the color made it stand out too much (frames are painted black.)

I found some 2" wide butyl tape and figured I'd cut off the excess. As long as you pull sharp, it breaks mostly clean. Pull slow and it's a mess.


Fold it over the edge of the window, cleco everything in place and leave it over night for the rubber to settle and bed. The cleco tension will squeeze out what's not needed and the window frame seals up tight.





Using a semi-hard squeegee edge, run along the window frame to cut the butyl. Make sure the squeegee is softer than the acrylic window and CLEAN or you will score a nice line in your new windows.





Of all things, WD-40 cleans up the smudges and excess with a microfiber cloth.



And put your rivets back in.

In case the photos dont display, here's a link to the album.

https://photos.app.goo.gl/Q8rk9Lgpr8pZehnH9

cheers,