E16 misfire

[Chilly]

Well, I have an interesting problem and would like some input.

Last weekend I tried putting my LOC Weasel up on an E16-4 and had three misfires, all on copperheads. On the first try, the igniter lit and there was plenty of smoke, but the motor didn't light. Second try, it didn't look like the igniter fired at all. Third try same...no smoke, but it looked like the pyrogen either burned or flaked off the end.

So now I have an unused reload sitting in the casing. Should I try lighting it off again, or just unload the motor and trash it to be safe? And for that matter, unloading could be difficult. The delay grain is pretty tight in the forward closure and could be hard to remove. Any suggestions? It's a cheap reload and I'm tempted to just toss it.

 

[RocketboyG80]

Well, if I were you I would just loosen the aft closure a little bit and keep it for the next time I fly. Or if you don't plan to fly anytime soon maybe, you could just static fire it in your yard. Do you have any other igniters that you could try?

 

[Chilly]

I've got some Quickburst twiggys but the pyrogen will need to be shaved to fit thru the nozzle. I've already loosened the closures but am worried about residue inside the propellant grain causing a CATO.

 

[loopy]

You could disassemble the main part of it (leave the delay grain in the foreward closure and put it in a ziploc bag) and scrape out the top of the propellant grain to eliminate the residue from the igniters. This might also help the motor light easier next time.

Loopy

 

[jetra2]

I left an E16 completely assembled for the better part of four months, and when I went to fire it in my Mustang, it lit perfectly the first time, WITH a Copperhead! I would say, in your case, just loosen the closures a half a turn and store it in a plastic sandwich bag with all the air squeezed out to keep the propellant from oxidising too much.

About using the Twiggy. If you wanted to, you could take the aft closure, aft o-ring, and nozzle off, then feed the igniter into the grain, then put it back together. You shouldn't have to worry about anything jamming, because once the igniter burns, it's burned to a crisp for, most of the time, the length of the propellant grain. It'll slide right out of the nozzle, and what doesn't will vaporize itself.

Jason

 

[jetra2]

I forgot to mention, always sand the grains of the propellants slightly to remove any oxidation, no matter how old the reload is. This'll help it ignite easier no matter what.

You might want to examine the propellant grain, if you do decide to disassemble everything but the forward closure and see if any propellant burned away during the misfires.

Jason

 

[MarkABrown]

E16s are notoriously hard to light. I've launched a few where I had to try 4 or 5 times to get it to light. Keep trying.

 

[Chilly]

Thanks - that's good to know! Believe it or not, until now I've actually had 100% success with crapperheads. I'll try taking the aft closure off and stuffing a Twiggy in there. I'm nervous about it though...

 

[n3tjm]

Use a Magnelite . It fits in the nozzle, and works every time .

 

[astrowolf67]

As Jetra said, with White Lightening loads, I always run a piece of sand paper through the grains slot a couple of times before assembly. White Lightening propellant tends to form oxidation on the surface. Also, bend the tip of the copperhead ever so slightly, so that it's in contact with the propellant when lit.

 

[Chilly]

It lit!
I removed the aft closure, sanded inside the c-slot and stuffed a Quickburst Twiggy in there, then re-greased the o-ring and put the closure back on. The Weez flew great to about 500'. It was nice, loud and smoky, which is why I got this rocket/motor combination in the first place. It's a great way to scratch the itch until our HPR field is open again.

Thanks everyone for your advice. This is one of those "learning experiences" that turned out well.