Here's the scoop:
You could use an aftermarket igniter with the Pro38's, as long as you are
diligent about making sure it is all the way up the core and in contact with
or in very close proximity to the igniter pellet. But don't use something
with 5 grams of thermonuclear goo on it, you won't change a thing about how
quickly the motor ignites. Just use something that will ignite the igniter
pellet, and that doesn't take much - your description of a nichrome-BP
igniter sounds suitable.
The reason we tell people not to use aftermarket igniters is as follows:
(1) It is unnecessary - properly installed, the supplied e-match will light
the igniter pellet every time.
(2) The main reason: Pyrogen dipped igniters will ignite the propellant
directly, the e-matches will not. Using an igniter with pyrogen overdip can
(and has) caused the occasional mid-port ignition and subsequent disaster.
One would think that with that easily ignited pellet at the top of the core,
that even if you accidentally touched off the propellant lower down the core
the darn thing would still go and the motor would function nominally. This
is true most of the time, however, there have been notable exceptions.
Stagnated cold gas in the core above the ignition event is far more stubborn
at allowing fire transfer than you might think - it is a far better
insulator than you'd suspect.
One fellow sent us the remains of a 6G casing and reload parts, with an odd
description of the event. What we recieved was the upper 2/3 of the casing,
a hardened puddle of aluminum slag, and the remains of the upper part of
the reload inert bits. Hmmm we thought... how did this happen. As he
decribed it, the button was pushed, there was a pop from the ignitor, then
nothing more than a road flare flame from the rear of the motor, that lasted
something like 1-1-/2 minutes. Eventually molten aluminum was seen to be
dripping from the rear of the motor..
We asked the usual questions, did you get the igniter all the way up the
core, did you use the supplied igniter, etc etc. Yes to all.
Baffled, I scratched my head overnight on the issue, wondering if the nozzle
had ejected at ignition, or if there was a blind drilled grain lower down,
or had we shipped a whole batch of propellant missing most of the oxidizer
(not likely), or what. But the problem was, as he described it the nozzle
did not blow out, and he had said he used the stock igniter which I knew, or
"knew" let's say from experience, would not ignitie the propellant directly.
I came to the conclusion that it must have suffered a mid to lower port
ignition somehow, sothought I that maybe the matches will on occasion ignite
the propellant directly. It is not unheard of that the match might snag
between grains and cause a misfire, it has happened a few times.
So, armed with some e-matches, a couple of 6G cases and J330 reloads I went
out to the test stand to play. I tried getting a midport igniton with the
stock e-match. Nothing, and in fact I have never successfully ignited Pro38
standard propellant directly with an e-match.
Next step - I rigged a pyrogen igniter using an Oxral match and about two
inches of double over igniter cord, and put this about 2" into the core.
A 2 minute road flare, and after about a minute the nozzle just sort of fell
out, and the bottom couple of inches of the casing melted away into a puddle
of aluminum. The motor never even came close to reaching operating pressure,
I doubt it would even have moved under its own power lying sideways on the
asphalt. The reamins were hard to tell apart from those sent to us by our
So, a quick email to the customer to report our findings. AHA! He confessed,
after thinking about it, that he had indeed used an aftermarket igniter, and
the conclusion was that it must have snagged in the core and felt like it
was all the way up.
We all laughed about this, because on the very positive side we had learned
something important from the event.
Now, all that said, in the installation instructions for the Oxral igniters
(now supplied with all Pro38 2G and larger reloads) I describe cutting off a
short piece of the red plastic tube used to shunt the bare leads, and
sliding this over the match head. This single feature increases igntion
reliabilty hugely - without the sleeve the output from the ematch goes in
all directions except straight back of course. Problem is, we want that
output to all go forwards towards the igniter pellet. The plastic sleeve
accomplishes this - I did witness paaper tests to prove the idea, plus some
hurried field testing when someone had problems with a Pro54 J. So do
yourselves a favor and don't skip this step - it is described on the little
paper instruction sheet accompanying the igniter. If this is done as
described, the match will ignite the propellant reliably even when separated
by a short standoff distance. But don't intentionally cause there to be a
standoff distance - get that igniter right up to the top.
FYI, we used to supply Daveyfire M28F's with all motors. Now, we only supply
them with the Pro38 1G G reloads, as they have nozzle throats too small for
the Oxral. Everything else gets Oxrals. These are the only two types of
igniters we provide.
Cesaroni Technology Incorporated
> Hello All,
> Sorry for the dumb question, but at the last launch I left behind a box
> 4 igniters that came with the Cesaroni pro38 reloads. I was told not to
> a "HOT" igniter to replace the lost ones, what would you recommend as a
> replacement e-match? I do not have an ATFE LTC so I'm stuck with few
> options, I however use nichrome/bp igniters for just about everything else
> they work with aerotech would they be ok? How about hotshot? Besides the
> starter grain, why would a pro-38 be any different then any other APCP