the 'packaging foam' or styrene foam planes are not meant to be durable, but are easily fixable. I started on a GWS Tiger Moth that was nearly 25% epoxy by the time I retired it. I couldn't count the number of prangs and fixes it had.<div>And of course I was adding more power all the time, went from NiMh to LiPo, then to a DIY brushless when I got sick of replacing the brushed motors after half a dozen flights.</div><div>But no matter how badly I ploughed the farm with the airframe it was fixable.</div><div>Each repair gives you a chance to add more strength to the airframe. </div><div>I ended up with not just a single carbon spar in the lower wing, but top and bottom carbon spars in both wings, plus flying wires (they made ALL the difference on a bipe), carbon spar down the fuse (each side eventually).</div><div>All this added weight but I just added more power. The plane actually became more stable and better to fly as a consequence.</div><div>When I purchased a second one, I built it from scratch with all the mods and strengthening I had used in the first one, and without the weight of all that epoxy it was the meanest quickest foamy at the field.</div><div>
</div><div>The Multiplex EPP foam is probably about the most durable on the market, although it is more flexible than styrene, but doesn't break like styrene, and you can use standard CA for construction and repairs.</div>