Herex V.S Rohacell?

Hi,

I`m about to order a new plane and have the choice between Herex and Rohacell. The modell will be a strong F3F modell. I know that the Herex is cheaper. So far I have built all of my own models with Herex. Is Rohacell only chosen for the lighter weight or is it other reasons why I should go for it? I want the strongest wing skins, and not nessesary the lightest wing. On my Avatar Jiri used Herex C70.75 on the D-box and Rohacell behind it, the wing is light and strong for the layup. You may answer in German.

Kind Regards

Kjell-Sture.

I personally would always choose Airex over Rohacell because of its increased robustness. Closed-cell, cross-linked PVC foams like Airex C70.75 (the change in product designation was made over 10 years ago) are less prone to delamination at impact, which is a most likely scenario at F3F. The mechanical properties of Rohacell are far more superior, including a much higher service temperature, but at increased costs, which is probably the major drawback. Super light applications, like for instance in F3K, mostly use Rohacell just because of the extremely low density the material is available at (and surely because the milling is much easier to do with).

Thanks Stefan,

This was what I had heard at some point, but wasen`t sure.