Will ejection charge corrode electronics?

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Nacho

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Hi all,
I was wondering, how bad is it to expose electronics to the fumes of the ejection charge (this would be for a C motor).
Thanks! :)
 

shonc182

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I'm not sure if there's a difference between the fumes and cloud of bits thrown away from the explosion, scientifically speaking....

But the electronics should be completely sealed from any detonation.

I ruined an altimeter by not sealing the small gap between wires and the small hole they passed through. I believe it's the barometric sensors that are particularly vulnerable.
 

seth_cooper

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The residue left after black powder burns is corrosive

Corrosion is bad for electronics
 

timbucktoo

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BP residue is corrosive and will harm any electronics. Not immediately but it will over time. If they are exposed, need to wipe them down with alcohol or other solvent that won't harm electronics.
 

prfesser

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I'm not sure if there's a difference between the fumes and cloud of bits thrown away from the explosion, scientifically speaking....

But the electronics should be completely sealed from any detonation.

I ruined an altimeter by not sealing the small gap between wires and the small hole they passed through. I believe it's the barometric sensors that are particularly vulnerable.
Please...don't use the terms "explosion" and "detonation" when describing the ejection charge. Two reasons: (A) they give the wrong impression to the reader, and (B) both are incorrect.

An ejection charge burns quite rapidly, but it does not explode (unless you're using the BATFE definition of 'explosion', which includes striking a match.) And *nothing* in model or high-power rocketry 'detonates'.

An internet friend who worked in some sort of professional rocketry job, described the difference between overpressurization and detonation. Essentially, in an overpressurization, the test stand is left in pieces. In a detonation, there are no pieces to be found. :oops:
 

John Taylor

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JLCU's are exposed by designe.
Other than a piston rocket like PML's what to do if anything? Perhaps for some reason it is not required. Thanks.
Anybody?
 

dhbarr

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My JLCRs are in pouches from Dinochutes.
 

dpower

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JLCU's are exposed by designe. Other than a piston rocket like PML's what to do if anything? Perhaps for some reason it is not required. Thanks. Anybody?
I always use a nomex chute protector when using a JLCU. Both the chute and JLCU are then protected. A decent amount of Estes/Quest wadding should also be sufficient.
 

solid_fuel

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The U, I believe, was a typo. And then repeated. The common abbreviation is JLCR.
 

Kelly

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Isn't a JLCR fully encapsulated? That is, the electronics are all fully enclosed in a case, and possibly potted in epoxy? I'm guessing there isn't any electronics exposure, even if not using the chute protector.
 

solid_fuel

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The case on a JLCR is around all of the circuits. But there are definitely external buttons and I don’t know if the components are potted. I don’t think they are. The directions, I believe, say to avoid direct exposure to ejection gasses.
 

John Taylor

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The case on a JLCR is around all of the circuits. But there are definitely external buttons and I don’t know if the components are potted. I don’t think they are. The directions, I believe, say to avoid direct exposure to ejection gasses.

I would expect there to be an opening for the barometric pressure sensor, right???
 

Brian H.

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There would have to be an opening for the barometric sensor, otherwise, the altitude readings would not be accurate. I may be wrong, but I believe the JLCR relies on the wadding to protect it from direct contact with the ejection gasses.
 
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