Grain direction on plywood fins?

[firemanup]

I picked up some 1/8" ply today for a scratch built i'm working on, and was wondering if the grain direction really matters with plywood?

I'm kind of assuming that the plys would have the grain laid perpendicular to eachother and this would rule out having to worry about which way the grain is on the fins.?

Am I correct?

thanks

Jason

 

[sandman]

Jason,

It prob. doesn't make much difference but, I line up the grain with the leading edge anyway...just me.

Now if it's just gonna be A to C engine powered then, NAW! It won't make any diff.

sandman

 

[jflis]

Jason,

For strength, it doesn't matter (much). YOu will get a slightly stronger fin and less flutter if you follow generic grain direction rules (using the grain of the visible outter wood as your que), but not a whole lot.

What folloiwng the grain rule *does* do, however, is make for a much easier to finish fin, for the leading edge anyway.

so, I would recommend that you align the grain as though it were a section of balsa wood. fwiw