Friday, August 21, 2015

Igniter Coat Testing

I've mentioned this in a post before. My supply of older (black pyrogen coated) Estes igniters is running low! Time to revisit lacquer coating the new Estes Starters.
While it's not an actual pyrogen, when coated this way the igniter will flame instead of just heating red hot.

I bought some cheap black fingernail polish at the Dollar Tree store.
Be sure the ingredients include Nitocellulose. That's the lacquer that will burn when heated.




I used the brush attached to the cap to paint the igniter tips.
Now they at least look like the old Estes igniters.  







Here's an Estes clear tip Starter igniter after the launch button was pressed. I'm using my old Estes 6 volt with four AA batteries.

It's hard to capture with my digital camera, but this clear tip isn't flaring up. The bridge wire is heating and red hot, the clear coat just melts.
The inset picture shows the igniter afterwards.
Here's the black lacquer coated tip after heating.
After this picture was taken the tip lit and flamed like a struck match! It took about 1/2 second for the flame to start.
The inset shows the black lacquer after it flamed up.

The new clear tip Estes Starters will ignite an engine when used correctly. They remind me of using bare nichome, it takes an extra second to ignite, where the older igniters were quick.
You'll see faster ignition using a 12 volt system.

8 comments:

  1. Many times with the new estes starters the thin connecting wire remains intact after use. I coat the tip with a blob of old nail polish and they still work great. I have reused the same starter four times! No real need to do this but I hate to waste them.

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    Replies
    1. Hi Jim,
      I'm cheap and have used MMX igniters up to 12 times!
      Use a six volt system (4 AA batteries in the Estes controller) and the bridge wire is usually intact. A 12 volt system will burn through the wire.

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  2. Wow, this really works? I've heard about it, but was a little skeptical. Always meant to try it just to see. It's always good to see some science being done.

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    Replies
    1. Hi Daniel,
      It's not the old pyrogen but it does help!
      A half second after the button is pressed and held, the lacquer dip burns like a candle flame. It doesn't spark, but flames up.
      I first read about using lacquer fingernail polish on bare nichrome wire in Sport Rocketry magazine. They used it overseas at the international competition.

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    2. Hi Daniel,
      It's not a solution, but a good "help".

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  3. Ah yes, yet another reason to hit the cosmetic section when you go the drugstore. As a kid I often used to get into trouble with my older sister for "repurposing" some of her stuff (tweezers, emery boards, nail polish as trim paint, etc).
    BTW, have you checked out the makeup sponges? they come in handy block and wedge shapes.

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    Replies
    1. Hi Naoto,
      I haven't tried the makeup sponges, I don't know where they would be used in rocket building.
      I do use emory boards for some shaping. I do go through a LOT of Q-tips! Very handy to pick up excess glue at the top a bottom of fin fillets. I even use them as a touch up brush to roll on paint on the outside edges of a fin.

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