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Titanium Tunnel

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  • #16
    Room temp epoxy and CF I don't know. The really good stuff, pre-pref, that you have to cook in an oven/autoclave, I have been told - don't be downwind in a crash/fire. Approach from upwind. I heard the hazard wss the CF. I don't know.

    If I can save 12-25 lbs, I will still use CF.

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    • #17
      Originally posted by svyolo View Post
      Room temp epoxy and CF I don't know. The really good stuff, pre-pref, that you have to cook in an oven/autoclave, I have been told - don't be downwind in a crash/fire. Approach from upwind. I heard the hazard wss the CF. I don't know.

      If I can save 12-25 lbs, I will still use CF.
      Oh yeah I was just talking about the tunnel, CF for panels, floors, other interior items is a great idea!
      Dave B.
      Edmonds, WA
      4 Place Quick Build

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      • #18
        Most of my aluminum floor boards need to be flexed when I install them. Splitting a rigid CF foam panel into smaller panels or some other creative idea may be required to install them.

        I too will be watching the weight saving calculations. The cub floor board weight saving study may have been comparing CF with plywood. My research showed aluminum was pretty hard to beat significantly weight wise....noise wise may be a different story. Also, You may find it beneficial to research Kevlar for its sound absorption qualities.
        Brooks Cone
        Southeast Michigan
        Patrol #303, Kit build

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        • #19
          Originally posted by Bcone1381 View Post
          Most of my aluminum floor boards need to be flexed when I install them. Splitting a rigid CF foam panel into smaller panels or some other creative idea may be required to install them.

          I too will be watching the weight saving calculations. The cub floor board weight saving study may have been comparing CF with plywood. My research showed aluminum was pretty hard to beat significantly weight wise....noise wise may be a different story. Also, You may find it beneficial to research Kevlar for its sound absorption qualities.
          How much did you have to flex the aluminum floorboards to install them. 1/8" cores can be flexed a bit, 1/4" cores a little bit. They get pretty stiff, pretty quick the thicker you get.

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          • #20
            Depending on how you fit the boards will determine how much they will need to flex. My floorboards are a very tight fit and they have to be flexed enough that there is no way a laminate CF would work. Without measuring I'd estimate I have to bow two of my floorboards so the center is 6" off the airframe to get them I'm place. I don't think it's that big a deal though. Pick your material then design a install that works.
            I'm a Tapatalk user so I can't see your "comment"

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            • jaredyates
              jaredyates commented
              Editing a comment
              Same here on the flex, I'd say about 6 inches.

          • #21
            Followup with the completed tunnel, turned out quite well I think. Matches the CRES original almost exactly. Mark was right, it was quite a pain to get those last bends, but hitting it real hard with a hammer did the trick

            tunnel 2.jpg
            tunnel 1.jpg
            bending.jpg
            Attached Files
            Dave B.
            Edmonds, WA
            4 Place Quick Build

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            • #22
              Update and a question. I was just test fitting my tunnel to the firewall flange and noticed this pillowing after it’s screwed on. Really not a fan of how that looks, is there any trick that might help?

              GLjpGAsbozaKah6jeYl1i2BqYWzOJlHK8c0QJiq4DpmICVHAgnsilAWa82In62VvLTBdZ_ggb0gCkbD4jD0xp-T3YfU-4LrW6pNY.jpg
              Dave B.
              Edmonds, WA
              4 Place Quick Build

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              • SteveF
                SteveF commented
                Editing a comment
                You could try heat shrinking it by using a propane or OA torch to heat it up, then gently hammer the swell down and let it air cool.
                If that doesn't work (it probably will though), you could also try heating it up, and quenching it with a soaking wet rag. You may have to repeat that process two or three times though, and that technique may also cause some distortion.
                Maybe practice on a piece of scrap first?
                Last edited by SteveF; 04-11-2018, 06:34 AM.

            • #23
              To me that is a "take your glasses off" situation, but then again my airplane is not going to win any beauty contests.

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              • #24
                Originally posted by jaredyates View Post
                To me that is a "take your glasses off" situation, but then again my airplane is not going to win any beauty contests.
                Yeah it's nit picking, just curious if there are any sheet metal tricks that could help. Though I don't see how. I'm definitely good with good enough. Having an experienced builder say so is welcome feedback, thanks!
                Dave B.
                Edmonds, WA
                4 Place Quick Build

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                • #25
                  A little shrinker on the edge might work, never tried on Ti before though.

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                  • Archer39J
                    Archer39J commented
                    Editing a comment
                    Hmm, I'll see about that. Have to get a shrinker for some other things and I have plenty of Ti scrap.

                • #26
                  I didn't see this mentioned, but if it was and I missed it I apologize...
                  For those who are interested in using Carbon Fiber, don't forget that it is electrically conductive and can cause galvanic corrosion. So you will need to put some kind of barrier (paint, etc) between the CF and any steel, aluminium, or other metal that it will be in contact with. Also, I recommend using Stainless Steel hardware (rivets, screws, bolts, etc) with Carbon Fiber and coating them with epoxy polymide primer, or some other barrier, and putting them in wet.
                  Also, CF panels are UV sensitive and don't do well in sunny places if steps to protect it from UV radiation aren't taken.
                  Last edited by SteveF; 04-10-2018, 01:57 PM.

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                  • Archer39J
                    Archer39J commented
                    Editing a comment
                    It also blocks RF. In case you were planning to put nav antennas in your wingtips, as one builder with a titanium tunnel I know was...
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