A

alcladrv

Well Known Member
On my -7A, in moderate rain, my slider canopy leaks somewhat in 3 places.

At the base of the windshield: A small amount of water will bubble under the windshield onto the glareshield. It seems the forward fuselage deck flexes enough to break adhesion with the formed in place fibreglass fairing. What's a good sealant to stop it? I tried a little silicone under the fibreglass outside. It seemed to slow it down. My plane's unpainted, so how will the presence of some silicone sealant affect the paint in this area?

Around the canopy lock handle: The small drop forms every 30 second or so around the shaft that goes through to the outside handle. Anyone found an o-ring or rubber washer that help would seal better?

Under the top canopy skirt and "doghouse": This area allows a lot more water in. If I hang anything clothing on the canopy rail brace at the top of the aft baggage bulkhead, it will get soaked. I heard the area behind the canopy is a "high pressure" area. What have other's used to better seal this area?

Other than a few leaks, the plane flies just as well in rain as clear air.

Thanks for your help,

Mike
 
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Sorry to say that it is not a good idea to place silicone anywhere near where you expect to paint. Paint will not adhere to silicone at all. Proseal or Lexal would have been better choices.

Can't help you regarding the leaks. The way I prevent them is to not fly in the rain. I'm too chicken to get near weather........
 
I won't comment one the other two leaks, but I did seal the area around the back bow very well. Knowing that the area is a high pressure area, I took some vinyl (actually I covered the rear skirt where it closes on the rear deck) and left the back 3/8" or so unglued. In other words, decorative vinyl is attached to the slider rear skirt, but the very back edge is loose. That edge is touching the fuselage. When the higher pressure moves into the slight void, it gets between the skirt and vinyl and presses the vinyl down on the fuselage. The seal is so good no air comes in at all. Water should be blocked, but I haven't flown in the rain since I did this.

Bob Kelly
 
alcladrv said:
On my -7A, in moderate rain, my slider canopy leaks somewhat in 3 places.

At the base of the windshield: A small amount of water will bubble under the windshield onto the glareshield. It seems the forward fuselage deck flexes enough to break adhesion with the formed in place fibreglass fairing.

Mike
Click to expand...

This causes me a bit of concern.
The fiberglass fillet around the base of the canopy is somewhat structural in nature for the attachment of the windshield to the airframe. If you have an area that has unbonded enough to allow in water, I would be be somewhat concerned that you have a potential for it all coming unbonded. When the surface is properly prepared and the layup is done properly, major effort should be required to get the layup to release from the aluminum skin.
 
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