Flying through rain canopy leaks

On a recent flight flying through an hour of mostly light and very occasional moderate rain I experienced a lot of water leakage from the front of the canopy, dripping down the instrument panel and avionics. The clearance at the front of the canopy skirt doesn?t allow for much material before making the canopy difficult to close. I?m thinking a neoprene type of material should block air and also not become waterlogged during prolonged flight through precip.

Has anyone had a successful experience sealing the front of the RV-4 canopy to prevent water leakage when flying through rain?

What I Did

As you indicated, there isn't very much room between the two forward mating surfaces to seal them without increasing the stress required to secure the canopy. So I went with an alternative route only used when flying in the rain (or expecting to prior to departure):

If your airplane was built according to plans, there should be approximately a 1/2" gap between the forward canopy frame bow and the instrument panel face. I got some EPDM 3/4" o.d. x 1/4" i.d. foam tubing, cut it slightly longer than the distance around the frame there (seems like it was around 30" or so), and "pushed" it up in that gap - letting the "squeezing" of the tubing from 3/4" to 1/2" there act as the seal.

It didn't seal all the water out - but it did direct away from the face of the panel whatever water got under the front "lip", and routed it down the sides until "leaking" onto the cockpit rails. At least it kept the instrument panel dry - I could live with a bit of water on the side rails.

I only used it when needed, and it was otherwise stored in my "tool box" under my seat. Available when needed, but not causing any undo stress on the closing mechanism when it wasn't.

YMMV

OBTW - As usual, it is available from the McMaster-Carr Aviation Division

I had the same experience a few years ago in my first moderate rain while IFR. I was really surprised how much water started coming in and it shorted out my GRT (was very happy I also had the Dynon!).

I tried a lot of different material but what has worked best is the really thin Urethane foam tape used for sealing windows. I put two rows of it side by side on the canopy lip. It will make it hard to close at first, but if you store the RV with the canopy down and locked it compresses enough to where it only takes a little pressure to get it closed. The adhesive on it doesn't hold up well so I use some very thin 3M double sided tape first then the foam tape after. I usually have to replace it about twice a year, but no water has made it's way in over the front since I've started using it

the only foolproof method of sealing ive found on my RV-4 is don't fly in the rain.

bob burns
Rv-4 N82RB