Once you burn the first igniter without lighting the motor, it is always harder
to light it with the second, and even harder with the third. The core gets
coated with soot which acts as an insulator. If you had the pyrodex pellet in
there, it is hard to imagine that not lighting. Maybe it did light but fail to
light the fuel. That would really coat the inside with soot.
Sent from my iPad
On Sep 5, 2017, at 4:44 PM, Dave M (Redacted sender "muldavea" for DMARC)
<dmarc-noreply@xxxxxxxxxxxxx> wrote:
No I was very careful next not to disturb anything. And the epoxy dries so
quickly that I didn't think it would have any chance to soak thru anywhere.
Sent from my iPhone
On Sep 5, 2017, at 4:36 PM, Gregory Lyzenga <lyzenga@xxxxxxxxx> wrote:
On Sep 5, 2017, at 4:22 PM, Dave M (Redacted sender "muldavea" for DMARC)
<dmarc-noreply@xxxxxxxxxxxxx> wrote:
A while back, I had two Cesaroni motors that were not plugged but I didnt
want the motor to blow the BP charge. So I removed the BP and filled up
with epoxy. Problem was, in each case, it took maybe three attempts to
launch. Kept burning out igniters. Any thoughts?
In the process of removing the ejection charge, did you disturb or damage
the igniter pellet at the top of the grain? Since Cesaroni igniters are
basically just e-matches without a bunch of pyrogen, there is a pyrodex
pellet at the top of the motor to get the ignition going. If the epoxy ran
onto that, it might explain your problem. But on second thought that seems
unlikely, since there would be a delay grain between it and the ejection
charge well. Hmmm… I’m not sure...
- Greg
----------------------------------------------------------
Gregory A. Lyzenga <lyzenga@xxxxxxx>
Dept. of Physics, Harvey Mudd College (909) 621-8378
Claremont, CA 91711-5990 mobile (626) 808-5314
