Papering SR-71 Fins

[smugglervt]

I'm working on my Estes SR-71 and I'm planning on papering the outer wings and top and bottom fins but was wondering if I should paper the balsa inner wing portion that the upper and lower cardstock body glues to. If I paper these inner wings will I have any issues with the cardstock not adhering as strongly to the paper as it would to the balsa? A little worried that the paper (I use self adhesive label paper for papering) may pull away from the balsa. I leave the paper away from the root edges of the wings and fins too ensure a good glue attachment. Does this makes sense or am I over-thinking the issue?

 

[Flyfalcons]

No need to paper that area.

 

[K'Tesh]

No need to paper that area.

I'm with Flyfalcons on this.

 

[smugglervt]

That's what I was leaning towards but nice to get some confirmation.

Thanks

 

[Mushtang]

Doesn't papering take the place of filling grains, and not really something that you'd ever do to balsa that doesn't show?

 

[K'Tesh]

Doesn't papering take the place of filling grains, and not really something that you'd ever do to balsa that doesn't show?

Paper also strengthens the fin, but that isn't the issue here.

 

[CORZERO]

No, it does not make sense. Yes, you are over-thinking this. However, if you do decide to go down that road, go ahead and paper the plastic nose cone while you're at it. Keep us posted!

 

[rharshberger]

Also remember that unless you have upgraded the motor mount to a 24mm that a C6 motor is the absolute minimum that a Estes SR-71 should be flown on, and even then they are marginal IMO. Definitely watch adding extra weight to them.

 

[Mushtang]

Speaking of weight, a little extra nose weight will help keep the plane from tipping shortly after take off and flying horizontal. There are a lot of stories of these doing just that. I've flown mine a dozen times and it's done this to me once, and after shoving more clay in there it never did it again.

 

[Micromeister]

I'm sure papering the outer wing tips and fins make save a little time filling grain.

You might also want to consider clustering this SR-71. I'm flying my 4th Estes SR-71 clustered version. My first clustered SR-71 used a C6-5 in the core with two B6-0 or C6-0 Booter motors in the outboard motor pods. Basic conversion really isn't difficult simply enlarging with plastic nozzles, addding 1/16th basswood intake cone bases with the aft end covered in at least two layers of either Aluminium Duct Sealing tape or Stainless Steel Tape. These two booster motors WILL eject at burn through no matter how much tape is used to secure them in the friction fit BT-20 motor tubes and that's PERFECTLY Fine. The only trouble with this set-up is if for some reason the Core C6-5 doesn't ignite at launch the BlackBird will make a very nice Up flight but suffer an awful core sampling return to earth. Yes my first SR-71 suffered such a Model ending flight.

To correct this I leaned to duct the two outer Booster tubes into the Main body tube through 4 pieces of soldered up 3/32" x 3/16" x .014" wall rectangular brass tubing.
These are epoxed into the 3/16" Balsa inner wing and into the BT-50 booster and Main BT-50 Body tube just ahead of the forward end of the main motor mount.
This type conversion does take a good amount of added Nose weight to bring the CG back to it's original location. I found adding all the added parts weight and the mass of one C6-7 motor does the trick.
These Clustered SR-71's can fly in B6-4 with two B6-6 in the pods or C6-5 core with a pair of C6-7's in the pods. Takes off like a bat! Recovers on a standard 18" plastic chute from WAY Up there

Hope these Mods at least gives you same ideas: Estes SR-71 are great semi-scale kits and a wonderful flying models. As others have mentioned if built straight from the kit, C6-3 should be the only motor used, I can't tell you how many I've seen eject after LawnDarting on B6-4, C6-5 & C6-7's over the years.