Foam Nose Ribs vs Warping

[Kamcoman77]

Has anyone that installed one, or two foam nose ribs between each of their ply nose ribs noticed any nose ply warping? I'm trying to decide if I should install a single foam rib, or use two between the ply ribs. I don't want to use two, if one will do the job.

[CHARLES DEBOER]

Some members have dampened the ply before closing the nose of the leading edge and had little or no dimpling. IMHO use one foam rib between each rib before closing the leading edge.  I had what I considered a lot of dimpling because, I think, I didn't dampen the ply. So I cut foam ribs and squeezed them into the leading edge area through the lightening holes in the spar by slicing them in half and applying epoxy just before installation.  This actually improved the shape and removed most of the dimples.

[Kamcoman77]

Thank you. I made a form to hold my wet nose ply in so it would dry in a curved shape. I have some 1"-wide foam that I will make extra nose ribs with. Hopefully, one foam rib in the middle of each station will prevent dimpling.

[Chuck in Indiana]

I wet mine, etc. and they were fine..until it went below zero in the winter. Gaaa! All of them dimpled except the bay where I got the extra piece from Aircraft Spruce. I'm guessing there was something different in the wood that came with the materials kit. Dunno. At any rate, it doesn't seem to affect the way it flies, just looks bad.
I *think* one would do it, Keith. (shrug)

[Kamcoman77]

Thanks for the advice. After reading a lot of other threads, I decided to put one foam rib between each ply one. In addition, I'll be water soaking my ply and letting it dry in a form for a few days before installing.

[pappyadkins]

That looks good... I added 1/8" rib every 12" - next one I may even try every 8"... those 1/8" ribs weight nothing & then 1/4" every 48" for the glue joints... this way I didn't even have to trim the plywood width...