Seal off ebay

Discussion in 'High Power Rocketry (HPR)' started by Steven88, Apr 14, 2019.

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  1. Apr 14, 2019 #1

    Steven88

    Steven88

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    hello, the instructions for my Perfect Flight altimeter say it’s a good idea to seal off the bulkheads, with an o-ring or silicone, from the ebay tube to keep the ejection charge gasses from reaching the altimeter inside the ebay. Is this a necessary procedure? I did put silicone into the hole that my wires pass through in the bulkheads to keep gasses out of there. Thanks for any advice you have.
     
  2. Apr 14, 2019 #2

    Zeus-cat

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    Not required, but I always see spikes in the data when the charges go off. One, maybe two data points at each event. Sealing the avbay might help. This is the data plot from a Stratologger on a dual deploy flight.

    [​IMG]
     
  3. Apr 14, 2019 #3

    djs

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    You don’t have to, but then your ebay will get gunked up eventually. Cheap fix though- get some poster tack and use it to plug the hole from the outside...
     
  4. Apr 14, 2019 #4

    Worsaer

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    The “gunk” becomes an issue, particularly because BP is corrosive. If you want your electronics to last, try your best to keep ejection charges out.
     
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  5. Apr 14, 2019 #5

    JohnCoker

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    It depends on what materials are being used. I'm suspicious of O-rings and plywood because I don't think the O-rings will deform into the grain. Maybe with fiberglass parts and perfect fitting an O-ring would work.

    Silicone could work, but that would be a big mess when you open it up.

    I do use silicone or poster tack to cover the holes where the e-match wire comes through the bulkhead.
     
  6. Apr 14, 2019 #6

    Andrew_ASC

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    What is poster tack and where can I buy it?
     
  7. Apr 14, 2019 #7

    timbucktoo

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  8. Apr 15, 2019 #8

    Nytrunner

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    Tim's right, look for the poster display and there'll usually be some hanging on a strip or small shelf right there.

    Any thoughts on a line of thin masking tape along the inner wall of the E-bay where the lid seats?
     
  9. Apr 16, 2019 #9

    cwbullet

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    In general, I do not seal my ebays. I will use poster adhesive putty to seal around wires if there is a gap between them and the wires to the ejection charges.
     
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  10. Apr 16, 2019 #10

    jd2cylman

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    I never "seal" the AV bay lids. All lids are stepped, and I seal the holes where the wires go through with 1" wide masking tape. Never get any residue into my electronics.
     
  11. Apr 16, 2019 #11

    cwbullet

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  12. Apr 16, 2019 #12

    Curtis Enlow

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    Dollar Tree has poster tack for a buck. Same as the stuff costing several times more.

    While I'm on the subject, their pack of disposable nail files are great for sanding slots or small details. 1$
     
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