Using old Aerotech composite motors...

[RocketSquirrel]

These motors i purchased from a guy clearing out a storage unit so no idea of the condition they were stored in. It was only 20 bucks for about 15 composite motors and a bunch of rocket gear. Looks like the Aerotech composite motors are from the 90's. I tested 2 of the E30's, first one went great but second one just popped and my rocket on fire. The F motors seem to be unusable because when you look at the propellant through the nozzle its swelled and you cant fit an ignitor in. What would you do with them lol

 

[Art Upton]

The White motors are going to be swelled. Not being a reload not much you can do with it for a rocket.

The Blue Thunder Motors might still work, but expect long delays , a 6 may turn into a 14 over the years.

 

[RocketSquirrel]

The White motors are going to be swelled. Not being a reload not much you can do with it for a rocket.

The Blue Thunder Motors might still work, but expect long delays , a 6 may turn into a 14 over the years.

Perfect i was planning to use electronics anyway. But it does concern me one i tried bursted into flames... is that typical of old motors or just par for the course, sometimes that happens

 

[Art Upton]

I've only suffered bonus delays or can't get an ignitor in it.

But others may have had bursts, I've run out of old motors I plan to ever fly. Only collectables left.

 

[Steve Shannon]

Perfect i was planning to use electronics anyway. But it does concern me one i tried bursted into flames... is that typical of old motors or just par for the course, sometimes that happens

It sometimes happens even with new motors.
I have had one forward closure failure on an old motor, resulting in torching a rocket on the pad, but I’ve flown many more old AT composite motors without ill effect. Inspect them first. Don’t be surprised if the old copperhead igniters don’t work. I now use firstfire jr igniters when I can.

 

[gldknght]

If you can't get an igniter in the motor, I'd say it's unusable. You might re-drill the cores if you have a suitable drill bit, but it would be almost impossible to get the core size right. Also this would qualify as a modification to a commercial motor. The safety codes do not permit this, and could be REALLY dangerous. I DO NOT recommend this.

That said, I don't know what you should do with any unusable motors. Just throwing them away doesn't seem safe either.

 

[SolarYellow]

I believe the accepted disposal method is to bury them in the ground with the nozzles sticking straight up and a cleared area around them and light them.

 

[Azamiryou]

I believe the accepted disposal method is to bury them in the ground with the nozzles sticking straight up and a cleared area around them and light them.

How do you light them if you can't get an igniter in?

 

[SolarYellow]

If it was my problem to solve, I would look into disassembly.

 

[OzHybrid]

If you're not worried about the delays, just wrap some heavy nichrome around the end of a bit of shooters wire and connect to shooters wire. Like the igniter making technique but with heavier nichrome. Clean out propellant in motor with a suitable length drill which will expose a bit of fresher propellant. Push your new heater/igniter up to top. Ignition is a push and hold till it lights.
The stuff I use is 32 Guage I think. 28Gauge Nichrome(found it) The label has fallen off.
Put it on a pad a bit further out....

 

[RocketSquirrel]

If you can't get an igniter in the motor, I'd say it's unusable. You might re-drill the cores if you have a suitable drill bit, but it would be almost impossible to get the core size right. Also this would qualify as a modification to a commercial motor. The safety codes do not permit this, and could be REALLY dangerous. I DO NOT recommend this.

That said, I don't know what you should do with any unusable motors. Just throwing them away doesn't seem safe either.

I might as well throw them away. I was able to get the ignitor in one, the core hadn't swelled up. I hit the launch button fire shot out the top of the rocket and its ashes now lol it was probably $5 in material so whatever, but yeah. Not safe.

 

[burkefj]

I've personally found you wind up spending more money in time and igniters trying to get small older motors to light and if you do thrust profile is off, chuffing, risk of getting barely off the rod and land shark or ground fire is high.

 

[ENTERPRISE NCC-1701]

The correct disposal method is to soak the engines in a bucket of water overnight. The dampness will make the propellant fall apart into a sludge. It is then safe to dispose of.

If you can't get an igniter in the motor, I'd say it's unusable. You might re-drill the cores if you have a suitable drill bit, but it would be almost impossible to get the core size right. Also this would qualify as a modification to a commercial motor. The safety codes do not permit this, and could be REALLY dangerous. I DO NOT recommend this.

That said, I don't know what you should do with any unusable motors. Just throwing them away doesn't seem safe either.

 

[Art Upton]

The correct disposal method is to soak the engines in a bucket of water overnight. The dampness will make the propellant fall apart into a sludge. It is then safe to dispose of.

That works for black powder motors, not sure of APCP?

 

[gldknght]

That works for black powder motors, not sure of APCP?

Since Aerotech motor casings are not made of cardboard, they won't dissolve in water.
Solaryellow in post #7 might have the right idea. And have a ABC fire extinguisher right next to you.

 

[ENTERPRISE NCC-1701]

Since Aerotech motor casings are not made of cardboard, they won't dissolve in water.
Solaryellow in post #7 might have the right idea. And have a ABC fire extinguisher right next to you.

You’re right! Ammonium Perchlorate has particular problems when disposing of. After reading the Hazmat precautions regarding this rocket fuel, the chemical composition only dissolves in water when it does not have the binder mixed with it. I forgot about that part

 

[Art Upton]

I recall in the PAST, that AP motors said to dig a hole , put nozzle up, fill hole up to nozzle; and ignite it from a safe distance to dispose of. This is what Solar likely was referring to.

 

[prfesser]

Generally, I would hand-saw most of the way thru the casing, the whole way around, snap it in half, then ignite in a hole as described. An alternative that I haven't tried but might work: pull off the paper retaining cap and dump out the BP. A small drill bit through the hole in the epoxy, and spin the bit by hand to drill the whole way through the delay propellant and into the WL propellant. Then put a really good starter in the hole and push the button.

 

[Rschub]

Then put a really good starter in the hole and push the button.

In other words, SOP?

 

[Alan15578]

Generally, I would hand-saw most of the way thru the casing, the whole way around, snap it in half, then ignite in a hole as described. An alternative that I haven't tried but might work: pull off the paper retaining cap and dump out the BP. A small drill bit through the hole in the epoxy, and spin the bit by hand to drill the whole way through the delay propellant and into the WL propellant. Then put a really good starter in the hole and push the button.

I'd be tempted to do a complete disassembly and autopsy, before cremating the remains, but that is a lot of work. I'd probably just put it in the city hazardous waste stream and watch them puzzle over it.

 

[prfesser]

In other words, SOP?

No, igniting from the forward end. Even if the drill only exposes clean delay mixture, that might be enough for it to ignite, and the flame from the delay would provide several seconds of pretty hot combustion products.

The hole in the epoxy used to pot the delay will melt and enlarge, which will slow down the burn.

If a long drill bit of the nozzle size is available, drilling from the aft end might be feasible, but I think you'd need to expose a lot of clean propellant surface, as WL propellant generates surface crud a lot more readily than delay material.