reload shrinkage...

While going through some reloads for my Aerotech 24/40 casing, I noticed that some of them had started to "close in" the core slot. I don't know how old they are, but as you can see, the grains are still in their original sealed bag. They've been stored under the bed (I figure if I'm happy enviro-wise, they're happy). This is an F39 grain. It's closed almost all the way shut. Is this going to be a problem using these grains? Can I pry them open and use them? Re-cut the slot to original size?

you can try to squeeze a popsicle stick in there to make the opening larger. you can also use some sandpaper to make the opening large enough to fit the igniter. I don't know about cutting it though.

Nail files work great.

Do not cut or "pry" the slot as this can cause a crack (imagine a rubber eraser getting cracked) which will create too large a burning surface and overpressurize the casing resulting in (at a minimum) the aft closure blowing off.

Try to fit a really thin igniter inside, and if you cannot, then simply sand the slot until it is wide enough to fit the igniter inside.

The Copperhead supplied should still fit.

It was likely swelled a bit from absorbed atmospheric moisture. This is common.

You may find the slot actually squeezes shut a bit more when you slip it into the liner.

An emery board is the easiest way to open up the slot. Or us an X-Acto knife to trim one side of the slot so that it's parallel to the other.

-Kevin

In most places I have worked, there are dessicant packs that get thrown away. I usually grab a few and throw them into my motor box. It'll help slow down this process.

I have flown reloads like this with no issues. Thread the copperhead into the widest area of the slot and pull it through until the head is seated in the slot.

Great reload, enjoy!

Like others have said, a nail file will work wonders. If more material needs to be removed a hobby knife can probably be carefully used. Estés pro series 2 igniters are pretty small and could probably be used if the slot is really small.
I think Crazy Jim put together something good about this but I can't find it now
Enjoy the motor!

As long as you can pull the copperhead or another igniter into the slot, no sanding is needed. Blue thunder does not oxidize or swell like white lightning and should remain easy to light.

Good point, blue Thunder is notoriously Easy to light, so if might not need much work.

Nate

nute said:

Good point, blue Thunder is notoriously Easy to light, so if might not need much work.

Nate

Click to expand...

+1 on that


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Here ya go..... some sandpaper & a file did it.

https://www.rocketryforum.com/showt...g-older-hobbyline-reloads&p=663030#post663030

Don't let them take cold showers. No more shrinkage. :blush:

ChrisAttebery said:

Don't let them take cold showers. No more shrinkage. :blush:

Click to expand...

Beat me to it :kill:

Adrian

I had the same issue with a package of E28s. Igniter fit in a little snug, but motors worked good

Sounds like a Seinfeld episode.