You don't want to build or strengthen to crash proof your airframe, you only need enough integrity to get the job done, just remember, the heavier the airframe is, the stronger it needs to be in order to carry the flight loads in the first place, and the higher the energy upon impact in the even of a crash, adding strength is adding weight and this is a vicious cycle, so be careful, weight goes on in grams and before you know it... []

ARF designs themselves are pretty good but in many cases they can show up on your doorstep from the manufacturer and have dry glue joints, they are already covered making things tough to get to at times, sometimes even joints that appear to be glued are dry or have voids in or under them, so thin C/A followed by medium in areas at this point are the only adhesives that will flow into these areas clearly making this your very best path to lightweight and structural joints.

I design and build my airframes exclusively utilizing C/A adhesives for the assembly of all wood substrates, and I use the methods of assembly that I earlier explained because I know them to work very efficiently and to be the lightest possible way to build as I have demonstrated in many of my on a diet documented build threads over the years, no matter what adhesive you decide to use don't start adding a bunch of thing you don't need, you will be sorry in the end...

Bob