Fuselage Firewall and Bracing


Once the fuselage is level and anchored, the first operation is to get the firewall cut and mounted.  This operation is probably the single best reason for the fast build kit.  The plywood which I received with the kit had both warped and bowed which required some real work to get it right.  I first cut and shapped the firewall close to the final shape.  Next, I glassed the face with a single bid and placed the panel between a 3/4 inch plywood board and a very solid and flat glass panel and weighed it down.  This seemed to work fairly well and got rid of some of the problem.  The panel warped again during installation however and required additional work to get straight.  

Vertical level for sitting firewall.  Note the
fuselage spacers to hold fuselage shape.
Firewall cut and shapped with horiz & vert
alignment lines.  Initial bonding operation.
Squaring the firewall to the fuselage.  I used
an 8 ft. straight edge to improve accuracy.
The bonding of the firewall is complete on
the front side and now ready for inside.

Firewall has been initially bonded into
place and bracing tacked in place.
Note the horz and vert alignment lines.  The
two holes are for nylon strap to hold tape
measure for one handed measurements.

Once the firewall is correctly positioned and squared, plywood braces are positioned and these are then glassed into place.  Each of  the lower braces are positioned just inside of the engine mount holes.  The upper bracing brackets the upper engine mounts.  The cross brace adds support for the nose gear.  The glass work for the inside of the firewall is probably the most difficult you will do.  This involves multiple layups with the individual layups having multiple overlaps.