Cowl mounting?

Discussion in 'Firewall Forward & Fuel System' started by lanceav8r, May 14, 2018.

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  1. May 14, 2018 #1

    lanceav8r

    lanceav8r

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    Has anyone here used piano hinge to mount their cowls like the Van’s aircraft crowd? If so what piano hinge did you use? Aircraft Spruce sells .050” thick aluminum extruded hinge with a stainless pin about .085 thick. I was expecting that something thicker like .063” would have been required but Spruce doesn’t seem to sell it.

    Is the .050” material thick enough?
     
  2. May 14, 2018 #2

    EAABipe40FF

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    Yes.
     
  3. May 14, 2018 #3

    TFF1

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    Too thick and it gets pretty hard to make it conform.
     
  4. May 14, 2018 #4

    smizo

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    we use the aircraft spruce piano hinge to join the two halves of the wolf cowl, or a carbinge if customers want to upgrade. still use traditional fasteners on the firewall.
     
  5. May 24, 2018 #5

    lanceav8r

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    11D441B8-26D9-4754-9E01-9613D34CB4BE.jpeg Test reply.
     
  6. May 25, 2018 #6

    bneub

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    I hadn’t seen the carbinge before. Those look cool. Do they work well?
     
  7. May 25, 2018 #7

    Neil

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    When we do a Glasair cowl we maintain the joggle so the joint looks nice and clean. Trim the joggle to about 1/2" tall and rivet the hinge with flush rivets. For a really nice finish on the outside, remove the jell coat before riveting and finish with a single layer of glass cloth over the rivet heads, then body work over the glass back to the level of the jell coat. This will prevent the rivet heads from "ghosting " through the paint as the aircraft ages.
    Use cam locks at the firewall. Scan.jpg
     
    Last edited: May 25, 2018
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  8. May 25, 2018 #8

    Tralika

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    Look for the wire at a Hobby Shop. They will have a good selection and very inexpensive. You can try several different thickness wire for just a couple bucks. I used piano hinge to on my Highlander cowl to join the top and bottom, traditional fasteners to join the back of the cowl to the fuselage. Also, do you know of the technique using two different size hinge, a 1.5" and 2".
     

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  9. May 25, 2018 #9

    Neil

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    Just to add to Post #7;
    Most of the cowlings we get are really too thin in the seam area and we add a minimum of 3 layers of cloth about 1 1/2" wide where the hinges fit. Also we use the 3/4" rolled hinge. I believe the wire is about.070".
    When you add the laminates the cowling should be placed on the airplane while they cure, if possible.
     
  10. May 27, 2018 #10

    lanceav8r

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    I have another question for you guys. Trying to decide if the cowl attach strip at the firewall should be permanently attached or removable. I can do it either way. Both have pros and cons.

    Anyone have any opinions or recommendations? IMG_4842.jpg
     
  11. May 27, 2018 #11

    cwilliamrose

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    The one that's attached to the firewall? No reason to make it removable that I can think of.
     
  12. May 27, 2018 #12

    Timbob

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    Nice looking engine!
     
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  13. May 27, 2018 #13

    lanceav8r

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    Yes. The firewall attach.
     
  14. May 27, 2018 #14

    cwilliamrose

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    I hope to make my firewall in one piece so it will have a non-removable flange. Christen Eagle firewalls are one piece.
     
  15. May 28, 2018 #15

    lanceav8r

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    Thanks guys. It is on there permanently now.
     
  16. May 30, 2018 #16

    lanceav8r

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    Made a little progress today. The halves are fitted and fiberglass flanges made today for the split line. This thing is so floppy and not symmetrical. IMG_4850.jpg
     
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  17. Jun 22, 2018 #17

    lanceav8r

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  18. Jun 22, 2018 #18

    Neil

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    I have had some cowlings that were so flexible that the larger, flat areas were difficult to body work. Simply adding glass usually just makes them heavier. A better solution, should you decide it is needed, is a layer of 1/4" light weight foam bonded to the area with a single layer of cloth over the foam. Bond the foam to the inside of the cowl with a laminating resin (we use Jeffco) mixed with some cabosil to thicken and use the same resin/cabosil mix to seal the side of the foam you will add the single laminate over.

    Glass cowlings look great because the shape is limitless but they are a lot of work and often end up heavier, some much heavier, than aluminum. Add wisely.
     
  19. Jun 23, 2018 #19

    lanceav8r

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    I was considering the foam. Thanks IMG_1634.jpg
     
  20. Jul 1, 2018 #20

    lanceav8r

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    Thanks to Smizo for the cowl help and suggestions. Now I’m ready for paint. IMG_5042.jpg IMG_5043.jpg IMG_5044.jpg IMG_5047.jpg
     

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