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  • #16
    I got my order of Oratex today, delivered. Right now I am planning on painting the nose, and wrapping the wings with mylar (clear.

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    • #17
      We have learned by doing with Oratex.

      My best recommendations:

      USE FRESH GLUE! I think we paid a big price for keeping glue too long. I would buy fresh every few months. I know it's expensive but I think you will get a much better result.

      Be careful in cleaning up glue "spills". Before the glue is heated you can clean it off. Once it is heated you ain't getting it off. This stuff really sticks once it is fully heat activated. You can heat it to a lower level and still clean it off but once you hit it with about 350 it is staying.

      As always, cut things with plenty of margin. Sometimes you think you cut it right to the limit and you are actually not accounting for something. Give yourself big margins for first cuts and then carefully reduce down to final fit.

      Start with less important areas and build up. You will only learn some things by doing. I started with the interior as I knew it was cosmetic and not flight safety related. This let me learn the fabric where it was not as important. Of course maybe not the prettiest work....

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      • #18
        I was looking to see how you handled the fuel line protrusion through the fabric, but I’m not seeing any? Are you planning to route those after you’ve completed covering the interior?
        Dave B.
        Edmonds, WA
        4 Place Quick Build

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        • #19
          Our fuel lines are not going to pass through any fabric from what we are planning. We don't plan on having fabric in the boot cowl area. The boot cowl will be left open but we could later make some sort of cover.

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          • #20
            Originally posted by Archer39J View Post
            Awesome, looking good! Can I ask, did you cover the boot cowl and other exposed AL parts or paint? I’ve been wondering how I might go about that when it’s my time. I too plan to use silver 6000 on the interior but blue on the exterior. I’m concerned about the color match with paint, especially if I can expect some fading after a time.
            I will be looking forward to seeing how your color combo works out. Sounds good!

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            • #21
              Originally posted by Archer39J View Post
              I was looking to see how you handled the fuel line protrusion through the fabric, but I’m not seeing any? Are you planning to route those after you’ve completed covering the interior?
              Here is how we did our fuel lines and fuel selector.

              Notice the selector is either ON or OFF. No right or left. We have both tanks feeding the selector and Mr. Gravity will send the fuel! Brent created the "Fuel Panel" and installed it in the Boot Cowl next to the left seat. The fuel lines feed down the left side of the windshield support and we have all the electric on the right side windshield support. That way we keep gas and electric separated a little! Notice in the picture showing the upper shot there are two fuel lines with green tape covering the open ends. One line will go to the left tank in the wing, the other will crossover the top of the windshield and go to the right wing.

              I gave a picture of the right side of the Boot Cowl to show you what it looks like without the fuel selector. We are keeping a bit of "steampunk" or "industrial" look but want to make it look like we at least finished it!

              Attached Files

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              • #22
                Originally posted by EricP View Post

                Here is how we did our fuel lines and fuel selector.

                Notice the selector is either ON or OFF. No right or left. We have both tanks feeding the selector and Mr. Gravity will send the fuel! Brent created the "Fuel Panel" and installed it in the Boot Cowl next to the left seat. The fuel lines feed down the left side of the windshield support and we have all the electric on the right side windshield support. That way we keep gas and electric separated a little! Notice in the picture showing the upper shot there are two fuel lines with green tape covering the open ends. One line will go to the left tank in the wing, the other will crossover the top of the windshield and go to the right wing.

                I gave a picture of the right side of the Boot Cowl to show you what it looks like without the fuel selector. We are keeping a bit of "steampunk" or "industrial" look but want to make it look like we at least finished it!
                Eric,
                I strongly suggest you review Bob's fuel system design, I fear Mr. Gravity is going to recall you to earth shortly after take off sometime. If you can get a siphon started, you may be able to run, but at sometime you'll get air in your lines and flow won't happen. Also need low point drains for water. Become familiar with and perform 150% max flow fuel rate tests on the ground including max climb angle, I don't have time to look for references for you now.

                You guys have done a lot of very very nice work on that plane, be safe!

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                • #23
                  What I did not show is the gascolator in the bottom of the cowling on the firewall. It is the lowest part of the fuel system and will be checked before every flight. We will have air vents in each gas cap plus an air balancing line from tank to tank to ensure that is one gas cap is blocked the other will allow the fuel tank to air vent. As I write this I don't remember but I am assuming we have a drain in the lowest part of the gas tank as well.

                  How is this different from a Cessna running on BOTH?

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                  • #24
                    PM sent regarding similar concerns as Marcus.
                    Brooks Cone
                    Southeast Michigan
                    Patrol #303, Kit build

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                    • #25
                      One goal is a continuous downward flow from the outlet near the bottom of the fuel tank (front and rear so take off and descending attitudes are covered) to the gascolator, no dips or rises for water or air to cause problems.

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                      • #26
                        I’m a newbie here and I don’t own a bearhawk, so please treat anything I say with a grain of salt - the other members are the experienced ones.

                        The Cessna system was pretty bulletproof and I liked its simplicity.

                        Regarding your fuel selector, check that if the fuel is inadvertently selected off on the ground, that the engine will exhaust fuel in the lines before the takeoff roll is commenced. You’ve labeled the fuel selector with an arrow but some fuel selectors have the arrow pointing the other way, and there have been mishaps where pilots familiar with other aircraft types got airborne with the fuel selector 180 degrees out, in the off position. Not an issue if fuel starvation occurs before you get airborne, but it’s also happened when the carb bowl has been swapped for a larger one, leading to an element of surprise after takeoff.

                        Looks like you’ve given your system a lot of thought and the fact that your selector can only be rotated through 90 degrees should in theory prevent this from happening.

                        Covering looks great btw.
                        Last edited by Nev; 06-18-2018, 08:09 AM.

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                        • #27
                          The Cessna 150 fuel system design is not suitable for a tail dragger, unless one puts a limitation on it that demands no take-off with less than 1/2 tanks.

                          The best fuel system for a typical taildragger is the fuel system that Bob Barrows designed. Its very similar to a Piper Cub STC'd fuel system design that removes the Cub's header tank.
                          Brooks Cone
                          Southeast Michigan
                          Patrol #303, Kit build

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                          • #28
                            We have NOT changed the fuel tanks guys! So our fuel tanks will feed exactly like they are designed. I am not sure how using a BOTH position changes that. The fuel is taken from the tanks in the exact same place. They both feed downwards to the selector and only then do they come together. We have the same cap vents for each tank. We intend to add a balance line for venting so if one cap vent gets blocked the other will provide venting. I don't know how you think this will siphon. Maybe if we maintain an un-coodinated turn for 5 minutes? The vent is at the top of the tank where there is not fuel. The fuel lines come together very low in the plane below the wings. If we get some way to siphon we will add a check valve but being a Taildragger does not magically make the fuel system do weird things. We have a Gascolator and an Aux Fuel Pump since we are using a fuel injected Lyconming IO-360. Pretty standard stuff! We aren't doing an auto engine conversion or adding a fuel tank in the baggage compartment.

                            It's an Experimental. We are not going crazy. We have eliminated needing to change tanks. Try to relax guys. I really don't want to kill myself in this thing and I will listen to reason and if I'm wrong I will back off, GLADLY!
                            Last edited by EricP; 06-18-2018, 11:11 AM.

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                            • #29
                              This is what comes to my mind when I see the aft fuel lines routing uphill and down the fwd posts along with the fwd lines.

                              In a climb attitude (which would be more than this, this is just 13 degrees) when the forward tank port gets uncovered you will starve the engine of fuel. Since these lines are combined below at the tee you can't maintain a siphon on the aft line, air will travel down through the forward line, through the tee, and back up the aft line as the weight of fuel in that line pulls the air along with it.

                              Just my take, but I would probably redo the lines so there was a positive head pressure at all flight attitudes as is achieved with the original design.

                              ETA: I don't think there's a problem with not having a "Both" option, other than you can't manually balance tanks which I wouldn't see being too big of an issue.

                              Untitled.png
                              Last edited by Archer39J; 06-18-2018, 11:36 AM.
                              Dave B.
                              Edmonds, WA
                              4 Place Quick Build

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                              • #30
                                Originally posted by Nev View Post
                                I’m a newbie here and I don’t own a bearhawk, so please treat anything I say with a grain of salt - the other members are the experienced ones.

                                The Cessna system was pretty bulletproof and I liked its simplicity.

                                Regarding your fuel selector, check that if the fuel is inadvertently selected off on the ground, that the engine will exhaust fuel in the lines before the takeoff roll is commenced. You’ve labeled the fuel selector with an arrow but some fuel selectors have the arrow pointing the other way, and there have been mishaps where pilots familiar with other aircraft types got airborne with the fuel selector 180 degrees out, in the off position. Not an issue if fuel starvation occurs before you get airborne, but it’s also happened when the carb bowl has been swapped for a larger one, leading to an element of surprise after takeoff.

                                Looks like you’ve given your system a lot of thought and the fact that your selector can only be rotated through 90 degrees should in theory prevent this from happening.

                                Covering looks great btw.
                                If you notice the Yellow Fuel Selector handle is pointing to the engine when ON and down at the floor (or ground!) when OFF. So we tried to add a big visual as to what the selector is doing.

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