Repairing a loose motor mount on a.40 size foam CORSAIR

[Frank v B]

Mark bought a foam Corsair at a swap meet for a song.  It has had issues with limited power output and a perpetually loose motor mount.

1) Limited Power output- 1) one magnet appears to have been chipped and the piece was loose inside the   
                        bell. See green arrow photo 29.
                        2) one of the 3 wire connectors broke off.  It looks about 2/3 of the strands
                        had broken off.  It could have broken during the less than perfect landing on           
                        its last flight. See green arrow photo 32.

2) To secure the motor- Mark had built up a plywood structure to secure the motor but it still shook itself loose.
 
My approach: secure Mark's reinforcement with fibreglass and epoxy and spread the load significantly via the full circumference of the large round fuselage.

step 1- take off the motor and the metal motor offset. photo 28.
step 2- dig out the firewall so it is flush with the plywood plate. Used an #11 blade. photo 30, 31.
step 3- apply diluted epoxy to the plywood and the foam around it to seal off the foam. Photo 34.
step 4- add fibreglass cloth over the entire circular firewall: foam and plywood. Add a second layer if more stiffness is required after the first layer has cured. Still to be done.

Frank

[Frank v B]

Glassing.

- add a drop of oil to the screw hole so errant epoxy will not stick to it. photo 35
- put a toothpick in each screw hole.
- cut the fibreglass cloth to size.
- add the fibreglass cloth and brush on diluted 5 minute epoxy (thinned 50% with rubbing alcohol). 
   Photo 37
- put the metal motor mount back in place over the toothpicks so the glass stays flat while it cures.
   Photo 38
- fill the entire area with epoxy to strengthen. (reduce flex)

Frank