Goonie Bird/CA question

The Rocketry Forum

Help Support The Rocketry Forum:

dragonshiprider

Well-Known Member
Joined
Feb 14, 2004
Messages
352
Reaction score
0
Hey all! I have a quick question regarding my Goonies.I am building two of Excelsior Rocketry's ultra-cool Goonies.The Goonie Max and the Goonie Bird Zero.Just a while ago I got the fins tacked onto the BT on the Max.Now I am pondering the notion of using CA for my fillets as apposed to epoxy or white glue.Will this be strong enough to handle C power?Just want some opinions on this before I do it.I've used CA on some of my smaller stuff including my mega fast Vector and Eclipse.
 

sandman

Well-Known Member
Joined
Jan 18, 2009
Messages
10,563
Reaction score
11
I wouldn't use CA for fillet.

CA gets brittle and weak after time. (well, most glues do that) but how would you smooth off the fill?

I wouldn't use my finger.:eek:

Elmer's is fine for the goonies.
 

powderburner

Well-Known Member
Joined
Jan 18, 2009
Messages
7,399
Reaction score
6
I think that a 'pure' CA joint would be too brittle--- maybe not.
At least, it would be relatively expensive. And quite stinky.

Put a white (Elmer's-type) or yellow (Titebond?) glue on the root full-strength for a structural root. These glues are tougher, and retain a small amount of flexibility. If you want a big fat fillet, thin a little bit of one of the water-based glues and stir in some balsa dust (we all SAVE our sandpaper by-products, don't we?). Apply in thin layers until you get the fillet you think looks good.

Note that with a good glue joint on the root, a fillet becomes a purely cosmetic thing. It really isn't very structural, and is not a necessary aerodynamic feature on a sport design like a Gooney. So whatever you think looks good is what you should build.
 

dragonshiprider

Well-Known Member
Joined
Feb 14, 2004
Messages
352
Reaction score
0
Thanks a bunch for the input y'all.Thing is that I had already attached (tacked) the fin on with a full length of CA.I've decided to just go with free hand beads of Elmers for the fillets.The first two are already laid down and drying.
I'm gonna post a summary of my technique in the TECHNIQUES section.
 
Top