5 Ply vs. 7 Ply Plywood

[Bartman]

Hi Guys,

I bought a sheet of 3/8" birch plywood the other day but it's 5 ply instead of 7 ply. It's for a landing gear attach plate and a firewall. I think it's fine for the landing gear attach plate but what about the firewall? I only mention it because I noticed just now that the plans call for 7 ply but I'm thinking 3/8" 5 ply is still plenty for a 100cc if I use fender washers to prevent crushing on the back and a nice broad mount to help the bearing loads on the front side.

Opinions?

 

[dhal22]

Very minimal strength difference in my opinion. You will be fine.

 

[Terryscustom]

7 ply will crush less and add more weight. You will need to prepare for some crush when you install you engine but it's plenty strong as long as you have a four sided engine box. Use fender washers or similar and broad base engine standoffs like SWB sells. Landing gear plate as well, you will obviously have some more structure like aluminum angle or something there to support the gear anyway.

 

[Bartman]

ok, thanks for the replies, in it goes!