OLD Aerotech Reloads

[enderw88]

I made a rookie mistake a few months ago. A couple was at our club launch selling off their deceased uncles rocket stuff. I bought a bunch of E18W8 and F39 Aerotech reloads. Fast forward to last Saturday and I tried to use a few of them. That was when I noticed the date stamps on the labels were from 1997, yes, 17 year old reloads. The propellant grains were pretty swollen, but I could get igniters in. I tried to fly two, but neither ignited properly. They sputtered, put out just enough thrust to get off the launch rod but not enough to get stable. Needless to say, the flights were more exciting than I like. Knowledgeable folks at the club were surprised that they did so poorly even with their age. We surmised that the igniters weren't hot enough. (I did not use the copperheads that came with the reloads, I used newer Aerotech igniters from a recent batch of reloads).

Yesterday I loaded up a case with one of the old reloads and a copperhead igniter from the package. I made up a horizontal test stand to test the motor. Same problem. Motor sputtered for over ten seconds. The delay charge seemed spot on.

I have a batch of First Fire Jr. on the way and will conduct at least one more ground test. Should I just write these off to experience or are the reloads still useable with the right igniter?

 

[cavecentral]

F39s are blue thunder and might have the best chance. I have E18s that are giving me trouble after 6 years.

I wouldn't waste igniters you paid $$ for if they aren't lighting. I make enough of my own, that I can use 2-3 igniters to try them.

 

[5x7]

I have had great results with 20 year old F39s. Make sure to measure the delay lengths and check them against the aerotech delay reference pdf. I have no doubt F39s will fire fine for years to come. Swollen white lightning loads may work with varing degrees of sanding the ends and the slot to expose fresh propellant but I would use them in saucers.

 

[samb]

I would try one more test. Sand the heck out of the grain slot before you build the reload. Pick an igniter with a good amount of pyrogen and see if you get a better result.

 

[Buckeye]

A couple years ago, I burned several old H and I reloads of the same era - 1997. The hardware I bought with the reloads said "ISP." The delay assemblies were nothing like I had seen before, so I was very careful in building them and relied on electronic DD with motor as backup. The Blue Thunder loads were fine, and the White Lightning were more finicky. The motors chuffed for several seconds, seemingly going from H impulse to F impulse before finally leaving the pad! For igniters, they came with Crapperheads and a stick of thermalite. I tossed the Copperheads, but used the thermalite in conjunction with my home-brewed starters.

I suggest getting some of the igniters from Quickburst (they are called Gems, or something like that). They have the hottest burn that I have seen. Also, launch your motors in lightweight rockets such that they are still safe with fewer N-s of impulse.

 

[chadrog]

Sand the grain slots and faces of the white lightning motors, and lightly sand the delay grain faces. Make sure the stated delays are what's included in the package - I have a lot of old motors either mis-packaged or mis-labeled.
I sanded the slot of a G64 back open a while back, it had pretty much swollen completely shut. Lit it with the Copperhead provided, all aspects nominal.

 

[enderw88]

Sand the grain slots and faces of the white lightning motors, and lightly sand the delay grain faces. Make sure the stated delays are what's included in the package - I have a lot of old motors either mis-packaged or mis-labeled.
I sanded the slot of a G64 back open a while back, it had pretty much swollen completely shut. Lit it with the Copperhead provided, all aspects nominal.

Thanks for the advice. What do you use to open up the slots? I think i have a jeweler file that could get in there.

 

[chadrog]

Thanks for the advice. What do you use to open up the slots? I think i have a jeweler file that could get in there.

Just some 50 grit sand paper folded over a couple times, makes quick work of it.

 

[blackjack2564]

When dealing with old loads that are "iffy", the best route to follow: use them in saucer type rockets where delay accuracy doesn't matter.

Neither does "chuffing", any time during the flight........ they will still recover safely.

 

[shreadvector]

If the motor thrust is lower than the original spec (and longer burning), then using it in a saucer will result in a powered impact with the ground and possibly many seconds of flaming thrashing around setting wide areas on fire.

 

[blackjack2564]

If the motor thrust is lower than the original spec (and longer burning), then using it in a saucer will result in a powered impact with the ground and possibly many seconds of flaming thrashing around setting wide areas on fire.

Duly noted.

So far the ones I've dealt with have not met that criteria.
That's whats nice about this forum, stuff you have not encountered, is usually pointed out by some one else.

Thank you Fred.

PS when they are swollen to the point of forcing the starter in........ I throw the grains into the burn pile.

 

[new2hpr]

Slightly swollen grains - steal an emery board from the wife to open up the grain slot. Totally swollen shut? Use a hacksaw blade and open it back up. Either way, keep some of the dust in there for a little extra boost to ignition. You should have NO problem with the blue thunder loads.
-Ken

 

[bill_s]

If the motor thrust is lower than the original spec (and longer burning), then using it in a saucer will result in a powered impact with the ground and possibly many seconds of flaming thrashing around setting wide areas on fire.

I don't see why a saucer would be any worse -- due to low weight and high drag, it would behave the best if a motor operated unexpectedly with low thrust and long burn. The OP already said the thrust wasn't low enough to not leave the pad, with a conventional rocket.

 

[shreadvector]

Saucers are extremely dangerous with low thrust long burning motors as they tend to turn with the slightest breeze or cross wind and also from gravity.

Normal rockets with a good thrust to weight ratio and the proper launch guide will leave the pad with enough airspeed for the fins to keep the rocket going in the direction the rod or rail was pointed unless there is a high cross wind relative to the velocity of the conventional rocket.


Saucers go slower in general, and using a low thrust motor will result in it going very slow and it will arc over and it will hit the ground and it will bounce and thrash around on the ground. It might also do the flaming thrashing on the ground in the middle of the spectators or the parking area or the vendor area.

I don't see why a saucer would be any worse -- due to low weight and high drag, it would behave the best if a motor operated unexpectedly with low thrust and long burn. The OP already said the thrust wasn't low enough to not leave the pad, with a conventional rocket.

 

[bill_s]

^^-- I'm just saying that, for example, with a 3 oz. saucer running off a motor that could fly a 30 oz. rocket, there's a lot of margin for thrust reduction. I guess they're a little more unpredictable, they also don't go as fast or far. In any event, good point that these motors should be used only in a large non-flammable environment with heads up, in any rocket.

If the motor doesn't go up to pressure, it won't burn proportionately longer, it will have less total impulse. So don't expect full performance and yet be prepared enough for it.

 

[tightwad]

On swollen white lightning grains, I have used an exacto knife and recut the C slot to expose fresh propellant and then sanded the ends of the grains if not bulging too much. If the ends have a large bulge and makes it hard to seat it properly into the casing, trim flat with the exacto knife. My swollen loads loads performed normally and came up to thrust without cuffing. Save the trimmings to use starter as fodder.

 

[dshmel]

My swollen loads loads performed normally and came up to thrust

Sorry, I read this differently and chuckled. Too much chocolate.

 

[Swissyhawk]

I'm sure hoping old aerotech reloads work. I recently received a box of them. The smaller motors date back to 91 and the H's and I's date back to 94. It also came with some Dr. Rocket hardware which I hadn't heard of before.

 

[5x7]

I would try to use the WL loads first. Get the White lightning loads into a sealed container with dessicant packs, the others should be fine. What are the reloads there?

 

[Swissyhawk]

"What are the reloads there?"

Here's the list without any duplicates or ones that just have different delays.

I161W, I154J, I357T, I300T, I284W, I211W
H123W, H73J, H242T
H180W, H97J, H128W
G75J, G104T, G64-7W
F37W, F62T, F40-7W, F22-7J, F24-7W

 

[5x7]

Fantastic. that is a ton of fun there. I flew an I161 this summer that was in older packaging than what you have. The unwrapped grain was pretty oxidized, but I sanded the oxidation a bit and used it as the aft grain (away from the igniter), and it burned great for a nice flight.

 

[fyrwrxz]

I just flew a 19 year old G-80/10 to 4k and it worked perfectly. You really have to worry about the ejection charges sneaking past that paper crimp cap and leaving you no deployment.
(yeah I know it's a single use, but I had to tell everybody because I was so surprised at it myself)

 

[fyrwrxz]

I'm sure hoping old aerotech reloads work. I recently received a box of them. The smaller motors date back to 91 and the H's and I's date back to 94. It also came with some Dr. Rocket hardware which I hadn't heard of before.

View attachment 245733

And that, my felow TRF'ers. is how you make new friends real fast here! Congrats on the score, buddy!

 

[DJDeadParrot]

I bought a pack of D9-4s from 1997. The first one I tried took 4 attempts to light it, even after sanding the propellant slot to expose 'fresh' propellant. The second one only took one attempt. Both chuffed a bit, but not too bad.

I haven't flown the third one yet because the second flight took the rocket beyond a treeline last month. I'm going back tomorrow to see if I can spot it now that most foliage is gone.

 

[bill2654]

And that, my felow TRF'ers. is how you make new friends real fast here! Congrats on the score, buddy!

That is one HECK of a score!

 

[Swissyhawk]

Now I don't think it turned out to be a very good score!

I tested a couple of the motors today at a club launch.

The propellant grains were very swollen as shown in the first photo.



I sanded the grains a lot so an ignitor would fit in it. I was using fastfire jrs.

My first rocket was an AT ARCAS with a G64. There was a several second delay before the motor ignited. Then the rocket flew right off the pad and went up very well. Unfortunately, the ejection charge never activated and the rocket nosed over and came straight down. Inspection of the motor after the flight showed that the delay charge had burned up. Maybe the BP was bad. In case someone asks, the steel mesh typically found in AT rockets wasn't plugged up because I didn't use that in this rocket.



Unfortunately my altimeter didn't survive. That kind of hurt. I thought they were rated for 25g's.



My second attempt was an AT Warthog on an F40. This time I replaced the BP with fresh BP. There was a couple of second delay before motor ignition and then it chuffed and puffed all the way up the launch rail. It cleared the rail but then it arced over at about 45 degrees. It flew across the field and nosed into the ground. I had a 7 sec. delay on it. I believe it buried itself before the ejection charge should have gone off.



I was impressed with the strength of the Warthog. I just need a new nose cone and it will be ready to fly again.

At this point I'm thinking that I won't be using anymore of those engines. The potential for slow erratic liftoffs really bothers me from a safety point of view. And of course, trashing a rocket on every flight gets pretty expensive.

 

[cavecentral]

I never trust the delay on older motors. Either use them in rockets you are ok if the above results happen, use electronic deploy, or remove the ejection and fly in a saucer.

 

[shreadvector]

Use them in models that weigh well below the normal max weight of each motor type and slow thrust buildup and longer delays will not be an issue.

And do indeed sand the delay faces and replace the BP ejection charges.