RE: 1/6th A-6 Intruder Scratch Build
That was the problem that my old roommate and i had, because we used the same plans......We ended up using expandable foam in between the bulkheads, you do this by taking wax paper on one side of the jet, whethor it be top, bottom,,,etc. Put the wax paper and tape it to the bulkheads, and spray the foam in. It is MESSY, but quick, you dont have to worry about getting it perfect, when the foam is dry, take a razorsaw and hack most of the excess away. BE CAREFULL, A LITTLE BIT OF FOAM GOES A LONG WAY! You dont want to distort the bulkheads, also a good idea is the make some cross-connectors out of wood, it can be 1/4 by 1/4 balsa just to connect the bulkheads to one another, inside the plug, it will help from distortion....Just an idea.
After planking my Ziroli F-9 years ago, i will do anything in my power to never have to do that again!!!!!! It was like building a friggin boat man!