This is something that I noticed during the final stages of my Orion cloning. I don't really like working with epoxy, so I tend to save up all the projects that need it and get them done in one fell swoop. The Orion was one that I swooped a couple of weeks back. Since the nose cone is resin, and Mike (Moldin' Oldies) cautioned not to trust the original recovery loops that exist on the reproduction, I've taken to strategically epoxying a screw eye into the bottom of the cone so I have something to attach the recovery system to. Since I was mounting a screw eye in the bottom of the cone, I decided to epoxy the six pod cones in place for the sake of security. I spread the epoxy around the inside rims of the tubes at both the top and bottom, then slid the cones in and pushed them in as far as they would go. The next day when I went to pack up for the launch, I noticed that several of the cones had risen up slightly so that they were no longer sitting flush with the top of the body tube. I figured that there must have been some heat created during the curing process which caused the expansion. I showed this to Scott McCrate at the launch that day, and he came up with the same explanation. (But HE had a big fancy word for it.) I meant to try to get a picture of it tonight at home, but I got busy elsewhere. I tried to blow it up some. This is the best I could do.

Attached Thumbnails

 

__________________
Bill Eichelberger
NAR 79563

http://wallyum.blogspot.com/

I miss being SAM 0058

Build floor: Centuri Mini Dactyl Estes - Low Boom SST Semroc - Marauder, Shrike, SST Shuttle

In paint: Canaroc Starfighter Scorpion Estes F-22 Air Superiority Fighter, Multi-Roc, Solar Sailer II Semroc Cyber III

Ready to fly: Estes - Solar Sailer II Semroc - Earmark, Groonie Der V 1/2

I used epoxy for gluing the cone on my X-24 Bug with no problem. I'm probably just being Mr. Obvious here, but I think the problem you see on your Orion is because the tubes were completely sealed and the heat of the epoxy curing expanded the air in the tube. If you were to have made a small pin hole in each tube somewhere that wouldn't have been noticed to let the air escape, this probably wouldn't happen.

BTW, I mix my (5 min) epoxy in small plastic mixing cups and the unused portion makes the cup very warm to the touch. (I also use this excess to gauge when I can stop holding parts in place by how much it's set up.)

__________________
John Lance Ladd
Yoyodyne Propulsion Systems
Grovers Mill, NJ
Established 1938
lladd.netau.net

I was thinking along the same lines myself, and perhaps the pin holes could have been run along the line where the pods would attach to the pylons. Also, I tend to "butter" both mating surfaces with epoxy to get a better "grip". Epoxy is such a heavy adhesive, you only want to use as much as it absolutely takes...

I don't use 5 minute epoxy; I prefer a slower-cure (20- or 30-minute) epoxy as it is much stronger after curing, and the exothermic reaction is less (it doesn't generate nearly as much heat from the chemical action...).

__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635

I could also have attached them one at a time. Or used CA.
BTW, Exothermic was the $5 word that Scott used.

__________________
Bill Eichelberger
NAR 79563

http://wallyum.blogspot.com/

I miss being SAM 0058

Build floor: Centuri Mini Dactyl Estes - Low Boom SST Semroc - Marauder, Shrike, SST Shuttle

In paint: Canaroc Starfighter Scorpion Estes F-22 Air Superiority Fighter, Multi-Roc, Solar Sailer II Semroc Cyber III

Ready to fly: Estes - Solar Sailer II Semroc - Earmark, Groonie Der V 1/2