Q1 Plans Chapter 15 Page 15-3

Details

Category: Quickie Plans

Published: Monday, 12 May 2008 10:28

Written by Dan Yager

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With this framework now mounted securely in place, you can now begin the final trimming of the canopy. The various sketches in this section should be studied to help. Basically, the sides of the canopy should rest against the grey tape on the longerons, the aft canopy should fit flush with the aft canopy bulkhead, and the front part of the canopy should follow the contour of the front cockpit cover. Don’t be discouraged as you trim, cut, and sand several times. The better job you do here, the nicer the finished canopy will look.

If the main wing cover has already been made you might set that in place to judge the canopy height at the aft canopy bulkhead; if not, just remember that the cover is about .33” thick.

The aft end of the forward cockpit cover will have to be trimmed so that the edge conincides with the canopy edge. This is so that glass tapes can be wrapped around the corner joint later.

After you have established the final canopy trim line, place a layer of grey tape as shown, inside and out. This grey tape will help control the glass layup that you will be doing on the canopy. You won’t have to worry about the layup portion on the grey tape. Next, sand the plexiglass dull inside and out within that zone. Round all the edges of the plexiglass so that the glass will flow smoothly around the corners.

Bondo two wood sticks(nominally 1/2” square) across the canopy stiffeners, as shown. These sticks will prevent the stiffener from bowing in.

Next, Bondo a board(nominally 1-1/2” by 3/4”) to each side such that by wedging mixing sticks in between the board and the canopy, the canopy will be positioned against the stiffeners.

You will want to join the canopy to the stiffeners and the aft canopy bulkhead with micro. After fitting the canopy dry, you can mix up the micro, spread it on the stiffeners and bulkheads, and use the mixing sticks to force the plexiglass against the bulkhead and the stiffeners to get a good bond. Let the combination cure overnight. The purpose of this whole exercise is to secure the canopy to the frame so that when the whole works is removed, the alignment will not change.