Hmmm... I know all about launching from former cotton fields... (now cow pastures-- we used to farm cotton before it got too be too much of a rich man's game).
Sounds like you're running into some sort of coating issue... perhaps the solvents are attacking the coating or something and causing a problem-- hard to say for sure. My wife got us started on using "cleanbacks" (as she and her mother called them-- using paper a second time on the back, whether it be from mail, etc...) but when it comes to papering fins, I just use a clean sheet of printer paper. We buy the cheap printer paper (20 lb bond AFAIK) at Walmart and like I said, I've had ZERO issues and I've been doing papered fins for a long time that way.
Are you CA'ing the balsa fin stock BEFORE papering the fin?? If so, that'd cause problems, because the CA basically DOES turn the balsa to a composite material (in the basic sense of the term-- a composite being a fibrous substrate soaked with a hardened resin, with the balsa being the fiberous material and the resin in this case being the hardened CA.) Wood and white glues simply don't bond well to CA-- it's about like trying to glue on plastic fins with yellow carpenter's glue or white glue-- it just don't work! (not well, anyway)... Now, if you're papering the fins FIRST and allowing them to dry overnight, using a THIN layer of white glue to paper the fins, and THEN CA-ing over the paper, then that would work very well... I've done that a time or two myself-- no problems. Personally, I'd do the first pass of a double-glue joint over the root of the fin to give the wood glue it's "best hold" by giving it first crack at the raw balsa FIRST, let that dry, and THEN do the CA coat of the paper-- just to make sure... after all, if the wood glue has already been applied and soaked into the root edge grain, it's penetrated into the wood as far as it's going to go, and there's nothing to lose if the CA soaks into the wood grain right up to where the wood glue has already penetrated. In fact, that'll probably get you the strongest fin and joint possible.
To glue the fin on, just use the second half of the double-glue joint (that I've described with pics in several threads; but there's a tutorial on papering fins heavy with pics in the Dr. Zooch Vanguard Eagle Beta Build thread, and I think I did some stuff on double glue joints with pics in the Dr. Zooch EFT-1 Beta Build thread as well...) The double glue joints are ridiculously easy, give you the speed of a fin glued on with CA (but probably at least double the strength and no weak shear plane, and no brittleness with age unlike CA), and double glue joints make THE strongest wood glue joint you can get, period... In the Vanguard Eagle thread, there should be a pic of this, but I had the upper stage go a little wonky on me on the first flight, and the rocket turned 90 degrees in midair and impacted horizontally on hard packed clay ground (former cotton field) at high speed, with one fin pointing straight down-- it was right around burnout so I don't know if it was still under thrust or not, but it hit HARD... the front outer 1/4 of the papered fin (trapezoidal) from the leading edge back and tip edge in took the brunt of the impact and disintegrated-- the wood and paper were physically ground to dust-- and then the fin snapped off... More correctly, the glue joint did not fail... the fin didn't break-- the layers of the paper tube RIPPED OFF about halfway through the thickness of the tube... the fin root, dry yellow wood glue, and lightly sanded glassine layer of the tube were all perfectly intact, complete with the undamaged TMTG fillet-- the layers of the paper tube let go of one another and let the fin come off with half of it. Totally fixable, and flew again later without incident. Just had to cut and paper a new fin, and build up the missing layer of paper with wood glue, sand, and repaint the damaged areas.
Anyway, hope that gives you some ideas...
Good luck with your project!
Later! OL JR
