April 6, 2002
I took the SkyPirate to the Dallas
Area Rocket Society's monthly club meeting. After the
meeting, some of us went out for dinner and an anticipated problem,
thermal expansion of the PML Quantum tube, revealed itself in an
There are dozens of posts
on RMR about Quantum tube and thermal expansion. Typically the posts
concern the ejection piston not fitting right because of temperature
fluctuations changing the diameter of the Quantum tube. So what
temperatures, I left the rocket in the car while dining.
When I came back to the car, I was surprised to discover
the epoxy joints between the strakes and main wings
had split. What I had not considered was that the
Quantum tube would expand lengthwise as well.
This both surprised and
concerned me. First, my project was extremely well built. Two centering
rings were used ahead of the fins and tons of epoxy reinforced with
microfibers, were used for the internal and external fillets. Second,
these were mild temperatures and Texas can get a lot hotter.
My solution to the strake/wing separation was a two
phase process. Phase 1 was rebonding the pieces. This
time I baked the rocket in the car, letting the joints
expand and break apart as much as possible. I then
removed the rocket from the car and did a quick epoxy
application to the joint and returned the rocket to
the car for to cure.
applied a thin layer of fiberglass over the joint.
Hopefully, this will hide any future cracking.
The external fillets,
got a layer of Elmer's Fill'n'Finish, which was then sanded down
as smooth as possible.
Primered the SkyPirate. I tried something different
on the primer. The first coat was Krylon primer and
the second coat was DupliColor primer. Additional
work has been set aside until I'm finished moving.
Look for updates in July.