Making your Cessna-style windscreen watertight


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Well-Known Member
Jan 30, 2012
New Zealand
How do you normally go about making a clean and removable installation of a watertight windscreen?

I have been told first hand that your avionics are at risk if no water-sealing is used.

Sure, there is nothing to stop you just injecting a bunch of silicone or caulk around the edges, but that is not going to last forever or more importantly be easy to remove and replace.

I had planned to just use butanol rubber stripping around all the fairings, but now I wonder whether that is sufficient?

Max Torque

Well-Known Member
Dec 16, 2011
Arizona/Alaska/several nasty places around the glo
Down in Central & South America, where it rains a LOT and with diverse temperature extremes, we used a tape:

Polysulfide Sealant (MIL-S-1103E).
Black. Extruded Tape.​
-40° to 180°F (-40° to 82°C)​
Oil & aromatic hydrocarbon resistant sealant. Maintains bond even when submerged in solvent.
Will not craze plastics.​
Bonds to itself. Meets or exceeds MIL-S-1130E, TypeIII

GS™ # 424
Available from: General Sealants, 300 S. Turnbull Canyon Rd, City of Industry, California 91745.

Works great and remains flexible, but working with it after it has been laid down is not as clean as what's in the video. We used it on all our windows. Floorboards too as sealed them very well and kept the blood and gunk from the wounded/dead from creeping underneath and corroding things.

I use it on my planes too.


Dan Thomas

Well-Known Member
Sep 17, 2008
That Polysulfide tape will allow the windshield to shift a little in the airframe, as it needs to, without allowing leakage. Silicone tends to act more as an adhesive, which can cause cracking when cold weather makes the plastic shrink much more than the aluminum or composite airframe. I have seen windshields worn halfway through due to chafing against a flexing airframe when that tape, or some felt tape, wasn't used between the windshield and airframe.