Salvage 20+Year-Old Motors ???

[kjhambrick]

All --

I still need to take an inventory but I've got a magazine full of 20+year old motors that I don't trust any more.

Yesterday I flew an Aerotech RMS-29/180 H128 W on a Level 1 re-cert flight that smoldered on the pad for 6-seconds before liftoff and then only produced something like 80-Nsec rather than the expected 178 N-sec.

I still need to analyse the Blue Raven Files to get a thrust curve but first things first and that's for another thread.

I bought all the motors in my Magazine at CA / NV Desert Launches so how they were handled before I bought them is beyond my control.

But since I've owned them, the motors have not been 'abused' -- I've kept them cool and dark in my Magazine for the past 20-years or so.

I've got White Lightning, Blue Thunder and a few Black Jack Motors along with a Kosdon L and a few I Motors.

Is there something I should look for on the RMS Grains to identify 'bad ones' ?

Is there a difference in the aging process of the different Propellant Types ( I imagine so ) ?

Finally, is there something I could do to restore the RMS Grains before attempting to build and fly these motors ?

In addition to H,I,J,K AT Reoads and a few Kosdon Motors, there are a bunch of Single Use G-Motors that may be beyond all redemption

Anyhow, I've tried to search the forums for a similar thread and haven't found a similar discussion ...

Thanks !

-- kjh

 

[Art Upton]

WL motors absorb water and have white salt looking stuff on them when old. Sanding that "salt" off the core and ends help.

 

[kjhambrick]

Thanks Art.

When I built the H128, I didn't see anything like white crystals on the grains but I only looked at the ends and not down the cores.

I need to edit my ( poor ) video down to a reasonable size before I post it but that is where I came up with the '6-seconds of smoldering' ...

I've had motors chuff in the past but this was different -- the motor literally smoldered before liftoff.

Thanks again !

-- kjh

 

[tsmith1315]

I've flown old (15-20) AT Green and BT motors with no trouble.

 

[kjhambrick]

Thanks Tim.

Got a few BT but none of the Green Motors.

I'll try a BT next after a thorough inspection as Art suggested

-- kjh

 

[tfish]

I've flown a few old motors in my day. In my experience...
The kosdon motors will be fine as is....as will the blue thunder. As others have said the white lightning will need some help. A light sanding to remove and expose fresh propellant helps. I also add a sliver of good propellant to the core of the top grain. This gets them going quicker then just the igniter..

Tony

 

[terryg]

I flew 25 year F52 blue thunder reload last month without problems. I have also flown older black jack reloads also. White lightning reloads are a different story. For those sand the grains and use them on saucers and the like.

 

[kjhambrick]

Thanks tfish and terryg.

Next flight will be an AT H220T that I've got on hand from 1999 or so.

Then I'll try with an AT H180W after inspecting and maybe cleaning up the grains and the core and definitely adding an ignition enhancer.

Nice thing about flying the Blue Raven ( or any good Accelerometer ) is that as long as it can detect liftoff, it should deploy at Apogee wherever that may be.

-- kjh

 

[Art Upton]

Thanks Art.

When I built the H128, I didn't see anything like white crystals on the grains but I only looked at the ends and not down the cores.

I need to edit my ( poor ) video down to a reasonable size before I post it but that is where I came up with the '6-seconds of smoldering' ...

I've had motors chuff in the past but this was different -- the motor literally smoldered before liftoff.

Thanks again !

-- kjh

That is what one old single use WL motor I had do

 

[Johnly]

I burned a 15 year old I300T on the test stand years ago and the motor and delay time were within NFPA 1125 specs.
Like you, I have a bunch of really old motors collected, and by far the worst aging motors I have used are the "red" propellant formulations.
Slivers of blue propellant or BKNO3 igniters are helpful with old WL motors after the grains surfaces have been abraded.

 

[Sooner Boomer]

My experience is that WL motors absorb water the worst. You get white granular stuff on the surface, and likely the (fuel) grains will swell. Unfortunately, this is a result of an irreversible reaction between a metal in the fuel and water. Even if you scrape the surface, the chemistry inside the grain has changed. I've had bad experiences. One - a G64 reload, chuffed and sputtered on the pad. It finally lit and took off, but by this time a significant portion of the delay grain had already burned. Fortunately, the thrust was very anemic, so the rocket didn't get vet high when the ejection went off early. The second example is from a bunch of 24mm reloads I was gifted. They were 20+ years old, but had been kept in an air-tight ammo box. I ground tested one. It was hard to light. I think it took three good igniters to light it. It had a very different sound (not the usual roar), and made very gray smoke instead of the white. This degradation is sad because I have some G55 motors I'd like to use.

 

[Sandy H.]

I also believe using a good hot/long burning igniter can help. I don't have any specific recommendations as to which one to use, but when I have trouble lighting old motors, usually a club member or onsite vendor will get me an igniter that gets the motor going.

I don't trust delays on very old motors, so they either get replaced with fresh delays or flown in a saucer or with electronics.

The only motors I scrap are motors where the grains are obviously swollen and won't fit in the liner. If its just the ends that are bulging a little bit, I sand them flush and fly in a saucer.

[edit] Sooner Boomer posted while I was. I agree that old White Lightning motors do seem to under-perform a bit once they have a lot of that white salt oxidation. I rarely fly near the limit, so it doesn't necessarily cause any issues for me if electronics are involved. [/edit]

 

[StreuB1]

I've had no issues flying motors that are nearly 30 years old. I flew them often actually and none have any issues. One thing to mention, older motors should use augmented igniters. I always tape a sliver of BT propellant to the igniter and have no issues.

I think your motor was an anomaly or the igniter fell down in the grain perforation causing an ignition in the middle or aft of the grain.

 

[DabCat]

Where are you flying them?

 

[kjhambrick]

Thanks for all the info to all !

Dabcat --

I live near Austin TX now and I will be flying out here.

I didn't keep track of where I acquired the motors but I am sure some of them came from one or more ROC Stocks that I attended back in the late-90s or in 2000.

-- kjh

 

[DabCat]

Thanks for all the info to all !

Dabcat --

I live near Austin TX now and I will be flying out here now

I didn't keep track of where I acquired the motors but I am sure some of them came from one or more ROC Stocks that I attended.

-- kjh

Darn. If you fly at ROC still, I could show you my methods for getting old reloads to light well. I've got some special ignitors too that can light dirt.

 

[Art Upton]

Darn. If you fly at ROC still, I could show you my methods for getting old reloads to light well. I've got some special ignitors too that can light dirt.

You mean the special powder that will lite dirt? A famous Rocketeer , that has been on Discovery TV a few times, got his thumb burnt with it. They grafted skin from his backside to fix it.

In several posts back in the day , he would say "Kiss My Thumb"

 

[Johnly]

You mean the special powder that will lite dirt? A famous Rocketeer , that has been on Discovery TV a few times, got his thumb burnt with it. They grafted skin from his backside to fix it.

In several posts back in the day , he would say "Kiss My Thumb"

I know who that is.....

 

[DabCat]

You mean the special powder that will lite dirt? A famous Rocketeer , that has been on Discovery TV a few times, got his thumb burnt with it. They grafted skin from his backside to fix it.

In several posts back in the day , he would say "Kiss My Thumb"

Actually, it isn't. Its my drag racing secret, so don't spill the beans... I use the leftover propellant spirals from drilling the cores of propellant grains for EX motors. I stick them in containers with a desiccant and they'll light anything. Stick them in the top of a motor or on an ematch wrapped with dental floss and everything lights. Nearly instantly.

 

[Art Upton]

Actually, it isn't. Its my drag racing secret, so don't spill the beans... I use the leftover propellant spirals from drilling the cores of propellant grains for EX motors. I stick them in containers with a desiccant and they'll light anything. Stick them in the top of a motor or on an ematch wrapped with dental floss and everything lights. Nearly instantly.

So your propellant you are drilling out has that purple looking copper material added to it? You know what makes super blue thunder?

I made a motor I test fired with it, it pushed the Loki Nozzle out of the snap ring but it did not CATO, only broke the nozzle. I don't make EX any more and sold or gave away my materials.

 

[kjhambrick]

Actually, it isn't. Its my drag racing secret, so don't spill the beans... I use the leftover propellant spirals from drilling the cores of propellant grains for EX motors. I stick them in containers with a desiccant and they'll light anything. Stick them in the top of a motor or on an ematch wrapped with dental floss and everything lights. Nearly instantly.

Great ideas DabCat.

I tried to use masking tape to attach about an inch of an 'enhancer' from the olden days to the head of my ematch.

Either the tape wrap was too wide to fit or the tape bond was too flimsy to go thru the nozzle of the RMS-29/180 H128.

I believe it would have stayed attached and it would have gone thru easily with a dental floss wrap.

Adding some to my Range Box for single use motors or just in case I feel the need to enhance the enhancer that I'll be building into my reloads

Thanks !

I will also be adding some dessicant packs to my magazine ...

Thanks again !

-- kjh