radial mount firewall?

What thickness plywood and how did you reinforce the fire wall for a radial mounted .35/.40 engine?

I would use 1/4" ply and then reinforce with triangle stock behind the firewall once in the fuselage.

LAST EDITED ON Feb-25-04 AT 12:03 PM (CDT)
 
I do the same thing but add 3/4 oz glass & epoxy. I use 2 hour and blot out the excess to keep the weight down. The Gladiator in my avitar is .51 powered and its done the same way.

Also plywood come in different grades and differents layers. Example 3 layers or 6 layers and different wood. I try to pick the harder woods to get a solid mount that does not smash when the hardware is tightened.