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  • Irregularities on underside of wing

    From CJ Kimble@21:1/5 to All on Mon Jul 3 10:36:34 2023
    On the underside of one wing of my DG-303 is an area with dents or ripples. These irregularities have been there for a long time, but I have to wonder. Any idea what might be the cause?

    Here's a link to a photo: https://drive.google.com/file/d/11J1T6uGDEuEx0NeMYvddzedYWN7-i8I_/view?usp=share_link

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  • From CJ Kimble@21:1/5 to CJ Kimble on Mon Jul 3 10:50:02 2023
    On Monday, July 3, 2023 at 12:36:36 PM UTC-5, CJ Kimble wrote:
    On the underside of one wing of my DG-303 is an area with dents or ripples. These irregularities have been there for a long time, but I have to wonder. Any idea what might be the cause?

    Sorry, this link to the photo should work: https://drive.google.com/file/d/11J1T6uGDEuEx0NeMYvddzedYWN7-i8I_/view?usp=share_link

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  • From John Galloway@21:1/5 to CJ Kimble on Mon Jul 3 12:01:32 2023
    On Monday, 3 July 2023 at 18:50:05 UTC+1, CJ Kimble wrote:
    On Monday, July 3, 2023 at 12:36:36 PM UTC-5, CJ Kimble wrote:
    On the underside of one wing of my DG-303 is an area with dents or ripples. These irregularities have been there for a long time, but I have to wonder. Any idea what might be the cause?
    Sorry, this link to the photo should work: https://drive.google.com/file/d/11J1T6uGDEuEx0NeMYvddzedYWN7-i8I_/view?usp=share_link

    Looks similar to dents from wings being tied down on, or pushed up by narrow hard wing stands e.g. the older type of Cobra tripod stands(?)

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  • From mropitz1@gmail.com@21:1/5 to John Galloway on Mon Jul 3 12:20:09 2023
    On Monday, July 3, 2023 at 3:01:35 PM UTC-4, John Galloway wrote:
    On Monday, 3 July 2023 at 18:50:05 UTC+1, CJ Kimble wrote:
    On Monday, July 3, 2023 at 12:36:36 PM UTC-5, CJ Kimble wrote:
    On the underside of one wing of my DG-303 is an area with dents or ripples. These irregularities have been there for a long time, but I have to wonder. Any idea what might be the cause?
    Sorry, this link to the photo should work: https://drive.google.com/file/d/11J1T6uGDEuEx0NeMYvddzedYWN7-i8I_/view?usp=share_link
    Looks similar to dents from wings being tied down on, or pushed up by narrow hard wing stands e.g. the older type of Cobra tripod stands(?)

    Or sawhorses with not enough padding, etc. The ones that are in
    the FRP sandwich sections can probably be mostly removed by
    a person who knows what they are doing with a hair dryer, etc.
    If you don't know what you are doing, don't try it yourself. If you
    aren't careful, you can melt or burn the outer skin.

    Mike Opitz
    RO

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  • From Charlie M. (UH, Pi & 002 owner/pilo@21:1/5 to mrop...@gmail.com on Mon Jul 3 20:31:23 2023
    On Monday, July 3, 2023 at 3:20:12 PM UTC-4, mrop...@gmail.com wrote:
    On Monday, July 3, 2023 at 3:01:35 PM UTC-4, John Galloway wrote:
    On Monday, 3 July 2023 at 18:50:05 UTC+1, CJ Kimble wrote:
    On Monday, July 3, 2023 at 12:36:36 PM UTC-5, CJ Kimble wrote:
    On the underside of one wing of my DG-303 is an area with dents or ripples. These irregularities have been there for a long time, but I have to wonder. Any idea what might be the cause?
    Sorry, this link to the photo should work: https://drive.google.com/file/d/11J1T6uGDEuEx0NeMYvddzedYWN7-i8I_/view?usp=share_link
    Looks similar to dents from wings being tied down on, or pushed up by narrow hard wing stands e.g. the older type of Cobra tripod stands(?)
    Or sawhorses with not enough padding, etc. The ones that are in
    the FRP sandwich sections can probably be mostly removed by
    a person who knows what they are doing with a hair dryer, etc.
    If you don't know what you are doing, don't try it yourself. If you
    aren't careful, you can melt or burn the outer skin.

    Mike Opitz
    RO
    Agreed, other than at a spar, the structure is usually inner and outer "glass" with a foam core. It dents easily.
    I use either a decent hobby heat gun or an industrial version. You get the area warm so the resin relaxes some and allows the foam to expand a bit to remove the dent.

    NO, this is not a set of instructions on how to do it, just the basic idea.
    You can cook the surface finish, burn the resin, or worse. Any of these can be expensive to repair.
    I started on broken bits to get a feel before working on real aircraft.

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  • From Gianni Isotope@21:1/5 to All on Tue Jul 4 06:50:27 2023
    Agreed, other than at a spar, the structure is usually inner and outer "glass" with a foam core. It dents easily.
    I use either a decent hobby heat gun or an industrial version. You get the area warm so the resin relaxes some and allows the foam to expand a bit to remove the dent.

    NO, this is not a set of instructions on how to do it, just the basic idea. You can cook the surface finish, burn the resin, or worse. Any of these can be expensive to repair.
    I started on broken bits to get a feel before working on real aircraft.

    A former DG-303 owner I knew placed hot damp rags, boiled in water, on "ripples" in a large region of one wing and it somehow smoothed them out. YMMV.

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  • From John Sinclair@21:1/5 to Gianni Isotope on Tue Jul 4 07:34:11 2023
    On Tuesday, July 4, 2023 at 6:50:29 AM UTC-7, Gianni Isotope wrote:
    Agreed, other than at a spar, the structure is usually inner and outer "glass" with a foam core. It dents easily.
    I use either a decent hobby heat gun or an industrial version. You get the area warm so the resin relaxes some and allows the foam to expand a bit to remove the dent.

    NO, this is not a set of instructions on how to do it, just the basic idea.
    You can cook the surface finish, burn the resin, or worse. Any of these can be expensive to repair.
    I started on broken bits to get a feel before working on real aircraft.
    A former DG-303 owner I knew placed hot damp rags, boiled in water, on "ripples" in a large region of one wing and it somehow smoothed them out. YMMV.




    I would think your ship is safe to fly, but if you want full performance, you probably need to have that area re-finished. I have never obtained good results from trying to remove dents with heat. How’s the other wing?
    JJ

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  • From CJ Kimble@21:1/5 to All on Tue Jul 4 07:59:02 2023
    I would think your ship is safe to fly, but if you want full performance, you probably need to have that area re-finished. I have never obtained good results from trying to remove dents with heat. How’s the other wing?
    JJ

    The left wing is fine, no imperfections. I think the dents on the right wing were there when I bought the glider (2019), but I'm not certain. I've never put a wing stand under that area, in the middle of the wing.

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  • From Roy B.@21:1/5 to All on Tue Jul 4 10:47:45 2023
    I've seen damage like that caused by stuff like wingstands, tail dollys, draw bars, & tow out gear tossed carelessly in the front of a trailer with the underside of the wings exposed. In my trailer ( ASG-29) I have "curtains" made of a heavy moving
    blanket to protect the 15m tips from damage that way.
    ROY

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  • From CJ Kimble@21:1/5 to All on Sat Jul 8 07:00:50 2023
    I figured out what caused the dents. It was the way I was using my wing rigger, wiggling it out to remove it (during assembly) and wiggling it on (during disassembly), without first relieving the weight of the wing on the wing rigger cradle. Live and
    learn.

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  • From John Sinclair@21:1/5 to CJ Kimble on Sun Jul 9 08:16:41 2023
    On Saturday, July 8, 2023 at 7:00:53 AM UTC-7, CJ Kimble wrote:
    I figured out what caused the dents. It was the way I was using my wing rigger, wiggling it out to remove it (during assembly) and wiggling it on (during disassembly), without first relieving the weight of the wing on the wing rigger cradle. Live and
    learn.
    H


    Yeah, you must always install and remove the Wing Wheel parallel to the wing! I seldom found it necessary to adjust the height at the saddle, raising or lowering the fuselage, instead. I have seen several people misusing the tool, placing it at mid-span,
    rather than near the balance point! I even saw one guy placing the tool at the wing tip!
    There are several good videos showing the correct way to use the tool, I made it a point of pride to rig and de-rig, all by myself!
    Cheers,
    JJ

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