I have had poor luck with wing bolts on large scale airplanes. I am flying Ziroli Bearcats and a 96" P-51. I am using steel bolts. I have had problems such as the wood stripping. I tried blind nuts, they would com loose and spin. I tried brass inserts and they would come out. Ocasionally the bolt would fall out on it's own from vibration. I couldn't dare use any locktight to keep it in.

The solution for me was to bend some metal I had and weld a blind nut onto it:



The plate is then attatched to the block with a srcew:



I know not everyone has access to a welder but this is what ultimately worked for me. By fixing the nut I can now use some mild locktight to keep the bolts from vibrating out or loosening up.