BRYAN AIRCRAFT, INC.
Williams County Airport
P.O. Box 488
Bryan, Ohio   43506

 

HP-14
MOUNTING PLEXIGLAS ON CANOPY FRAMES

1.    HP-14 canopies are designed so that no holes are drilled through the plastic.  This eliminates cracking from temperature change and shrinkage.

2.    Wrap each glass around its' frame and mark where trimming is necessary.  1/16" clearance is recommended around all edges for expansion.  Any trimming should be done with a file or sander while the paper is still on the glass.  Avoid any nicks in the edges as Plexiglas is notch sensitive and will crack easily when bent if the edges are rough.

3.    Clamp the angles over the glass and to the frame.  Trim ends and corners to fit.

4.    Drill and Cleco about 3/8 inch from the end of each angle and space others about six inches apart in vertical edges of hoops and bottom side of other sections.  Drill with #41 drill, enlarge holes to size and pop rivet per print.

5.    The rear canopy glass is not heated when bent to fit frame.  Rather sharp strain may result at the top of the tubes which pass over the wing spar.  Clamp the angles against the glass in this area and carefully pass a small flame from a Bernz Burner back and forth over the angle so that a little heat as possible strikes the glass.  When warmed enough, the glass will bend at the edge of the frame releaving any strains which might lead to cracking later.  The angles can then be riveted to the frame.

6.  We have blue transparent, green transparent and smoke gra transparent Plexiglas for rear canopy class.  Please state color you prefer when ordering if you have a choice.

CAUTION: Do not apply heat to forward canopy glass as it will distort out of shape.