Sealing The PIK-20B Canopy

After reading all of the comments and advice about sealing a PIK-20B canopy,
here is what I did.

Keep in mind if a pneumatic (pump-up) seal is not used, the canopy design
dictates that the seals along the side rails and those that seal the front
and rear hoops be of different design.

FOR THE SIDE RAILS...
I removed the old pneumatic seal and removed the RTV silicone adhesive from
the groove. I then took 2 lengths of Frost King Rubber Weatherseal, Type
V25G, ($5.00 for 17 feet in the aviation aisle at Home Depot). This seal is
3/8" wide, 1/4" thick, quite soft and has a "D" shape cross-section with
adhesive on the flat side. I put the two lengths back-to-back forming a
somewhat oval cross-section. This fit the canopy groove perfectly. I used
rubber cement (RTV silicone is too difficult to remove) to glue this oval
seal into the groove. This I did on both side rails, and their length were
such that they just stopped short of where the rail begins to turn upward,
fore and aft. To see if the seal was making good contact, I sat in the
glider with a 0.020" machinists rule, I could not insert the rule between
the fuselage rail and the seal.

FOR THE FORE AND AFT HOOPS...
This was the challenging part because unless a pneumatic seal is used, the
grooves in the hoop areas are not usable. After experimenting with many
different materials, the best result was achieved using 1/4" thick, 1/2"
wide soft open-cell foam to seal these sections. The 1/2" dimension was a
little wide but it is easy to trim to the proper width. It did not matter
whether the seal was glued to the canopy or the fuselage, as long as the
seal engaged the surfaces outboard of the groove. The ends of each foam seal
were adjusted so that the oval side rail seals just overlapped the foam
seal.

RESULT...
The canopy closed and latched easily without distortion of the canopy frame.
There was no more noise or airflow coming from the canopy/fuselage junction.
The seals are inexpensive, easy to make and replace in the future.

PIK-20 owners may email me with any questions.

Paul