The International Cessna^® 170 Association

Has any one gone with a thicker plexiglass on side windows? What is the largest thickness you can use on a 170A?

Thanks.

Art

If you try thicker glass on the door side windows you will have problems with the rivet holes lining up......The window is assembled with cherry rivets. There is an easy way to remove them if you don't know ask for more info on that. I have been down this road....

You can use 1/8" on all the side windows but it's a snug fit. You'll probably want to use other than stock rubber seals. On the door windows I used some thin (1/16"?) foam tape on each side of the glass then exacto knife trimmed the excess after it was assembled. There is nothing wrong with using regular aluminum pop rivets to install the glass in the door windows.

You can cut your own and save money. Be sure to use cast acrylic not extruded. It's more money but is superior optically. A 4x4 foot piece will get all four windows.

Nothing like new glass.

Patrick Phillips wrote:If you try thicker glass on the door side windows you will have problems with the rivet holes lining up......The window is assembled with cherry rivets. There is an easy way to remove them if you don't know ask for more info on that. I have been down this road....

Patrick, don't be shy with any helpful hints! Jump right in, we're always interested!

I changed out all door and fuselage windows using 1/8" material. I had no problems with the door windows. I did drill a 1/4" hole on lower portion of frame to get the old rivet tails out so they wouldn't be rattling. Reassembled with Cherrymax p/n CR3213-4's. The lower side have a couple rivet heads that chafe on the door. I trimmed the heads attempting to provide adequate clearance. I may change 'em out with countersunk CR3212's as they still touch lightly. The original rivets chafed also. Reinstalled fuselage windows with AN470-3's. All was a "piece of cake" on mine.

Steve

I also had rivets (universal head)from the window frame chafe into the door frame on the bottom and forward edge.....I removed the cherries and installed counter sunk cherries problem solved....anyways more on removing cherry rivet removal....they are almost impossible to drill out the steel centers....the drill wonders off the the softer edgeof the rivet....what I do is use a dremel with a cut off wheel on its edge, grind the top skinny and then the steel center will punch out easy with a 1/16 " punch...then drill the rivet...

[quote="schefler"]Has any one gone with a thicker plexiglass on side windows? What is the largest thickness you can use on a 170A?

Thanks.

Art[/quote]

Art,
I have seen thicker windows installed in original Cessna window frames by starting with a thicker material cut to the original pattern and than run on router table to champher the outer 1/2" down to the thickness that fits under the window frame. I think you have to use Lexan for this to work as Plexiglass is to sensative to the stress risers created during the routering operation. The draw back with Lexan is that while it is tougher and resists scratching better than Plexiglass, scratches do not polish out of its surface as easily as they do in Plexiglass. When you do change the windows you will have to wear shades like this guy , the difference is that noticeable.
Johneb

steve grewing wrote: I did drill a 1/4" hole on lower portion of frame to get the old rivet tails out so they wouldn't be rattling. (clip) .Steve

There are two 1/4" holes on the bottom of the steel frame that are there to buck the rivets that hold the window latch piece. My rivet parts fell out of those with a little shaking. Also a great time to rivet the piece in and rid the window of a previously cobbed up "repair". Just pot a 1'4" rod or drill bit in the vise and slip the frame on it. You need three hands for this though.

Reviving this thread so the info is in one place.

What have others used for the actual seal that goes on the Plexi/Lexan on the edge in the window frame?

I replaced my windows with lexan it was a little over 1/8 thick and used a acetic acid free STV to seal in place . And used aluminium pop rivets to hold in place . It's my belief that Cessna didn't use cherry lock or cherry max rivets originally . There isn't any great stress on the windows in that configuration . I have flown many hours with my windows flapping in the breeze due to the heat of the surrounding area . The air flow holds them up against the wing . No issues after about 600hrs ..

What is STV?

STV is made by GE and is very clear ,I think is a derivative of a polyurethane . It even goes off under water and will stick to some thing that's wet. It's very expensive but I am blessed that I do not have to pay for it.it is given to as a trade sample. Boeing use it on there aircraft .

I have replaced the glass in 3934V and used the 1/4" windscreen, and 3/16" on the door windows, the door windows were the 4' bubble but the rear were flat. They when in with no big problems. tight fit, yes, impossible? no.

T.C. or anyone else,
Pros and Cons of the 4" bubble side windows???
I'm getting ready to do mine and thought us two big guys might fit a little better.
we are tight in the shoulders.
I had a crack in the right rear window finish up the other day and at 4500 ft alt. a 5"X"5"x5"
triangle shaped piece of the window went south. Just popped out with a loud crack like a gunshot.
In that area of the window there is a negative pressure with some buffeting.

I haven't rode in it with the 4 inch windows yet. I do know you can't allow it to open all the way, because they hit the wing.