To paint or not to paint

Discussion in 'Competition Rocketry' started by cptom21, May 31, 2019.

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  1. May 31, 2019 #1

    cptom21

    cptom21

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    I am building an Estes Yankee for a "B" streamer duration contest. Knowing that paint will add weight I'm not sure if I should paint or just leave as-is. I am pretty good at painting and it will have a smooth finish, but that will require 3-4 coats of primer and a few coats of paint. Just thought I'd ask the community their thoughts. Thank you! 20190531_072033.jpg
     
  2. Jun 1, 2019 #2

    Mike Helm

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    If you're worried about weight but still want some color...go at it with some markers. Sharpies come in lots of colors.
     
  3. Jun 1, 2019 #3

    lcorinth

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    Disclaimer: I've never done competition rocketry. But from what I've read, you want to ditch the launch lug and use a piston launcher to reduce drag and get as much altitude as possible so you have room for a nice, long descent.
     
  4. Jun 1, 2019 #4

    OverTheTop

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    If you can afford the weight then prime and paint. If it needs to be as light as possible then maybe just some Sharpie as suggested above, and maybe a go with some sort of polish, perhaps wax-based.

    I don't have much of a feel for the necessary parameters for streamer duration events. Your sims will guide you.
     
  5. Jun 1, 2019 #5

    K'Tesh

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    I would paper the fins, fill the spirals, prime and sand, then use markers for the decorations.
     
  6. Jun 1, 2019 #6

    dhbarr

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    Naked as a jaybird, marker to write on your details.

    Remember to externally side-attach your streamer somewhere in the neighborhood of the post-burnout CG/CP.
     
  7. Jun 1, 2019 #7

    prfesser

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    Am I correct in thinking that spray paint specifically for models can produce a thinner coat (smaller pigment particles)? Or is my memory up to its usual state?

    Thinner coat = less weight
     
  8. Jun 1, 2019 #8

    MClark

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    I would take a sample of tubing, weigh it, prime and paint, then rewiegh .
    Is the reduced drag of a smooth finish giving enough altitude to overcome the increased weight.

    M
     
  9. Jun 1, 2019 #9

    cwbullet

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    No pant. Fly it naked and let it earn the paint.
     
  10. Jun 2, 2019 #10

    K'Tesh

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    No pants? So, you're supposed to be naked?
     
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  11. Jun 2, 2019 #11

    Buzzard

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    I always painted competition models. After sealing the tube, use a light coat of a bright color. I also use car wax to get a smoother finish as it helps smooth the paint finish. Keep in mind that a smoother finish can result in a higher altitude, taking longer to return. The weight of the paint is minor if you don't go overboard. Also, the paint adds visibility and helps to protect the model if it lands on a wet surface.

    Flying competition since 1968,
    Chas
     
  12. Jun 2, 2019 #12

    BABAR

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    Good luck in your competition!
     
  13. Jun 2, 2019 #13

    rtuinila

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    Paint and polish. The reduction in drag due to the polishing more than makes up for the added weight of the paint.
     
  14. Jun 2, 2019 #14

    cptom21

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    Thanks everyone for the replies. I will go ahead and paint it (with spray paint of course). I might tone down the amount of primer I use, but then again most of that gets sanded off anyways.

    Every month we have 2 competitions at our club launch. One is changed every month (last month it was "A" cluster duration which I won first place). The other is the same the whole year and this year it is "B" streamer duration. I used an Estes Hi-flier last month with a 4" wide × 56" long mylar streamer that was folded accordion style. It did well, but I placed second and the first place rocket beat me by 24 seconds so I have a lot of ground (or air) (or time) to pick up.

    I'm also planning on testing before launch day on a b4-4 and a b6-4. I think I'll get a better result out of the b4-4, but that's why I am testing it first.

    Here are a few pics of last months Hi-flier and "A" cluster.
    20190518_144328.jpg 20190518_100300.jpg
     
  15. Jun 2, 2019 #15

    cptom21

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    I was intrigued by your suggestion of a piston launcher so I looked it up. I will check tomorrow at our club meeting, but I dont think it will be allowed for competitions. If the rocket carries the tube with it for any length of time then it is part of the rocket (I feel). If it completely separates in air (which it is supposed to) then it would disqualify the flight.
     
  16. Jun 4, 2019 #16

    lcorinth

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    Well, if you're talking NAR competition, pistons are pretty standard I think. If you're talking house rules, maybe not.
     
  17. Jun 6, 2019 #17

    Ez2cDave

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    Too heavy = You lose
    No piston = You lose

    Minimum weight + maximum altitude + "exotic streamer material" + "complicated folding procedure" + BIG Thermals = You Win
     
  18. Jun 9, 2019 #18

    BABAR

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    Estes HiFlier is a great rocket, but has a lot more fin surface area and relatively forward extension of the fins than optimal for competition. Fins sized and shaped and positioned more like the Estes Sprint will help you pick up several seconds compared to the HiFlier.

    Not promoting the brand, but ASP has some model designs that may help you

    https://www.asp-rocketry.com/ecommerce/ASP-Competition-Model-Rocket-Kits.cfm?cat_id=9
     
  19. Jun 10, 2019 #19
  20. Jun 10, 2019 #20

    Alan15578

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    You are absolutely right if you are referring to most floating head piston launchers. On the other hand, fixed head piston tubes do stay attached to the launcher, and are competition legal. Of course one could attach a Kevlar static line to the floating head piston tube and then argue that it is still part of the launcher.

    At sanctioned NAR competition they care less about the letter of the rules, and more about accepted practices. You would create a real storm if you started DQing floating head piston launched flights.

    So, what did your club tell you?

    You should probably use a B6-6, the 4 second delay is just too short. Your kit should still be competitive if finished well and kept light. It is kind of fun actually, to send the message to your competitors that you are so good that you can beat them with just and old Estes kit. I have won many NAR boost glide contests with the Astron Invader; when they see me bring it up for my second flight, they know they have lost.
     
  21. Jun 12, 2019 #21

    caveduck

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    Adding to what my former partner in crime said, in dead air (no thermals), high boost and low mass for low sink rate are king. In thermal conditions, picking the right air dominates everything else. In both cases you need good streamer material (typically 1-2 mil mylar) with many creased-in folds, and the large added altitude from a piston never hurts so at NARAM they're effectively mandatory these days. So much so that there was a serious proposal - supported by Trip Barber - to entirely ban pistons on the last rules revision cycle. Paint doesn't really matter very much. If you can do a lightweight competition finish it might provide a bit more altitude but that is probably the smallest factor in performance. A little dope or CA on the balsa is a good idea to reduce the drag from fuzzy wood.
     

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