Jabiru J450, Руководство конструктора

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Jabiru J450 Constructors Manual
General>Composite standard procedures
Tuesday, April 6, 2010 14 of 343
General>Composite standard procedures
Composite introduction
Composite construction techniques may seem mystifying to those who have never been
involved with composites before but they are straightforward and require only a few basic
procedures.
Composite surface preparation
For bonding composite-to-composite or composite-to-metal the surfaces must be prepared in
the following ways:
With peel cloth
Where it is known that a surface will be bonded to
another surface, peel cloth is usually incorporated in
the lay-up under the gelcoat to provide a bare, clean
„virgin‟ surface to aid the builder.
Typically peel cloth is included in the lay-up for all
structural components: vertical fin, horizontal
stabiliser, flaps, aileron pre-molds, etc.
To prepare the surface for bonding simply cut at the
edge of the peel cloth with a knife and peel the peel
cloth off as shown in the photo at right, then lightly
roughen the surface by sanding to provide a good
„key‟ for the epoxy to bond to.
Peel cloth is typically red in colour as shown, although other colours are sometimes used.
If you are in any doubt about the area that you intend to glass to, sand away the gelcoat and if
you see anything that is
not bare fibreglass then do not glass to it until it is bare fibreglass.
NEVER, NEVER , NEVER glass over the top of peel cloth!
Without peel cloth
Where there is no peel cloth for a bonding surface the surface must be free of gelcoat, grease
and contaminates and must be sanded lightly to provide a good „key‟ for the epoxy to bond to.
Metal
If it is necessary to bond to composite to metal, the metal surface must be degreased and
roughly sanded to provide a good „key‟ for the epoxy to bond to.
Summary
Careful surface preparation is extremely important when working with composites: all
surfaces to be bonded must be absolutely clean and must be roughened in order to provide a
good „key‟ for the epoxy to bond to.
Bare
surface
Peel
cloth
Gelcoat