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Ceconite covering process discussion and Nitrate/buterate dope

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  • Ceconite covering process discussion and Nitrate/buterate dope

    Thought I would start an independent discussion to ease the search process in the future using Terry Bowden's message from another thread.
    Someone with Stitts or other systems want to start another thread too?
    Hank

    Here's a related bit of information I found on the ceconite webpage... This is most often used with Randolph products...

    NEW SUPER SEAM
    Use: New Super Seam is an improvement of the original Ceconite Super Seam Cement. This new formulation is clear, vinyl-based cement that may be over coated with all Randolph dopes with no incompatibilities. New Super Seam has twice the peel strength of the original nitrate-based Super Seam or Rand-O-Bond. The �New� on the can differentiates New Super Seam from the original.

    Note: New Super Seam is a vinyl-based cement that should not be added to nitrate dope to enhance dope adhesion. In the past, some people erroneously added nitrate cements, like Rand-O-Bond or Super Seam, to nitrate dope to help tape adhesion. In fact, while this seemed to help in applying tapes, the high-solids mixture that resulted from this unwise addition actually promoted tape delamination during service life. In any case, DO NOT add New Super Seam to nitrate dope for any reason.

    Packaging: Gallons, quarts.
    Mixing: Use directly out of the can with no mixing. If the cement thickens or begins to dry in use, add MEK to bring it back to original viscosity.

    Application: Apply with a one-inch brush directly to the surface. Lay the fabric directly into the wet cement and force the cement through the weave with protected fingers or a squeegee. Cement only 12 to 18 inches at a time to prevent the cement from drying. Cement directly to epoxy-primed metal, epoxy-varnished wood, or epoxy-primed composite surfaces.

    Normal Shelf life: Generally two years unopened. Heat over 100 degrees F. can damage the cement. If the cement has been exposed to heat in storage, it will turn whiskey colored; do not use cement unless it is perfectly clear.

    Terry Bowden, formerly TF # 351
    CERTIFIED AERONAUTICAL PRODUCTS
    Consultant D.E.R. Powerplant inst'l & Engines
    BC12D, s/n 7898, N95598
    Tick Hill Airfield (XA-47)
    weblog: Barnstmr's Random Aeronautics
    barnstmr@aol.com

  • #2
    Re: Ceconite covering process discussion and Nitrate/buterate dope

    That would be a an absolute PIA and take forever. Here is how I install tapes on dope systems.

    Treat the tape job just as you were covering a plywood surface. You can't force the dope through the top surface you have to wick it up through the tape. After a wing is stitched, I spray at least 2-3 coats of dope over the entire surface until the fabric has a sheen which indicates the weave is full. Precut your tapes to length, and spray a pass down the rib or stringer your taping with a fan on the gun about an 1/2 to 1" wider than the tape. Lay the tape into the wet dope and it will wick all the way to the bottom. once the tape is layed, apply one more spray pass over the top to seal. Tapes will be fully saturated and have even fill with rest of the wing. Once all the tapes are on, it is then ready for final coats of nitrate and then butyrate. by doing it in this manor, I get a much cleaner finish with the end result. I almost never have to sand with exception of nibbing trash. this process is especially important with stits since you can't hide nothing by nature of the system.

    Comment


    • #3
      Re: Ceconite covering process discussion and Nitrate/buterate dope

      I've just re-covered a set of ailerons with the Ceconite/Randolph process for the first time (all my previous experience was with Poly-Fibre).

      In all cases, I've followed the manuals.

      I can see NO difference in these two processes, apart from the chemicals used and the shrinking temperatures of the fabric (and why that should be different is beyond me) and the number of coats required.

      RTFM and you won't go wrong.

      Oh...and new Super Seam is Poly-Tak.

      Comment


      • #4
        Re: Ceconite covering process discussion and Nitrate/buterate dope

        Originally posted by Robert Lees View Post
        I've just re-covered a set of ailerons with the Ceconite/Randolph process for the first time (all my previous experience was with Poly-Fibre).

        In all cases, I've followed the manuals.

        I can see NO difference in these two processes, apart from the chemicals used and the shrinking temperatures of the fabric (and why that should be different is beyond me) and the number of coats required.

        RTFM and you won't go wrong.

        Oh...and new Super Seam is Poly-Tak.
        The difference is that even though it says non-taughtning dope on the can, it still shrinks 1-2% per year where stits is vinyl based and does not shrink

        Comment


        • #5
          Re: Ceconite covering process discussion and Nitrate/buterate dope

          Originally posted by Robert Lees View Post
          I can see NO difference in these two processes, apart from the chemicals used and the shrinking temperatures of the fabric (and why that should be different is beyond me)
          RTFM and you won't go wrong.
          Ceconite doesn't have you shrink the polyester fabric as tight because you coat it with dope. Eventhough they call it "non-tautening" dope, it tightens over time, so you'd be more apt to crush the structure if you took the fabric right up to the same tautness that you do with say "Poly-fiber", which uses a vinyl based fill. At least that's what they told me.
          John
          I'm so far behind, I think I'm ahead

          Comment


          • #6
            Re: Ceconite covering process discussion and Nitrate/buterate dope

            So why would anyone use Ceconite/Randolph?

            With the higher ironing temeratures, Poly-Fibre allows you to get smoother fabric before covering and uses fewer coats.

            I must confess that I was not impressed with the Ceconite process.

            Comment


            • #7
              Re: Ceconite covering process discussion and Nitrate/buterate dope

              Originally posted by Robert Lees View Post
              So why would anyone use Ceconite/Randolph?

              With the higher ironing temeratures, Poly-Fibre allows you to get smoother fabric before covering and uses fewer coats.

              I must confess that I was not impressed with the Ceconite process.
              Nothing beats a dope finish when it comes to original looks. It is also the only choice if you are doing a cotton or linen cover job.

              Comment


              • #8
                Re: Ceconite covering process discussion and Nitrate/buterate dope

                My 41 had Ceconite/Randolph and the main thing is that you are still using Butyrate dope. There is just something about the smell and feel of it when you are doing fabric work (probably early stage brain damage).
                I know I will need to cover the 45 when the time comes and the real main reason I like dope is the way it looks on an antique. There is just something about that deep satin finish you get from dope. It looks even better over cotton or linen, but just try and find any.
                Hank

                Comment


                • #9
                  Re: Ceconite covering process discussion and Nitrate/buterate dope

                  I always thought the nicest thing about dope is that you can "rejuvinate" it.
                  I'm so far behind, I think I'm ahead

                  Comment


                  • #10
                    Re: Ceconite covering process discussion and Nitrate/buterate dope

                    Still working on the LH wing tank removal project on N95598. After buying the front and rear strut for the RH wing at $1,000, I finally scraped enough money together and bought all my fabric covering supplies for the patch job. I am using Ceconite fabric with the Randolph butyrate finishing process because thats what is on the airplane, last recovered in 1984. Today, I just started the patch job over three rib bays on the upper surface of my RH wing and 2 rib bays on the lower surface. I had some planning support over the phone from my I.A. Mark Julicher. I plan to provide notes on here as I progress through the project.

                    Right now here in Central TX we have about 95% humidity for the third day in a row. NOT GOOD DOPING WEATHER. But I got off to a good start today on the upper surface, cut out the fabric spanning across the upper surface from Rib 0 to Rib 3. I had help from my son, my wife, and her dad today... 3 generations... pretty cool! We all had to re-learn how to do the baseball stitch. I think we got about 50 stitches done on each of the four corners. it sure goes quicker when you have help. I am really going to enjoy getting back into this fabric work again.

                    Biggest thing I learned today is that baseball stitching goes a lot better with a needle about 1/16 inch diameter. We are using arc-curved needles but started out with the larger one (about 1.8 inch diameter). It was hard keeping the stitches tight after having such a large hole from the needle. I also learned I can go a lot faster from Right to Left than the other way.

                    I have the ceconite procedure manual # 101 and the FAA AC 43.13-1B that I am trying to follow. I also have been using some of the illustrations out of the Stits Poly-Fiber manual. The poly-fiber manual was the most help for the baseball stitch instructions.

                    More to follow... I will try to attach some photos as this progresses.
                    Terry Bowden, formerly TF # 351
                    CERTIFIED AERONAUTICAL PRODUCTS, LLC
                    Consultant D.E.R. Powerplant inst'l & Engines
                    Vintage D.E.R. Structures, Electrical, & Mechanical Systems
                    BC12D, s/n 7898, N95598
                    weblog: Barnstmr's Random Aeronautics
                    barnstmr@aol.com

                    Comment


                    • #11
                      Re: Ceconite covering process discussion and Nitrate/buterate dope

                      Originally posted by N96337 View Post
                      I always thought the nicest thing about dope is that you can "rejuvinate" it.
                      To a point, but if it is cracked or ringwormed it will still show in the new finish.

                      Comment


                      • #12
                        Re: Ceconite covering process discussion and Nitrate/buterate dope

                        Rob,


                        I too Read The FULL Manual and I had the same question about shrink temperature. So I spoke with the fine folks who own the STC for both Ceconite and Polyfiber. What they said is that even so-called non-tautening dope actually still tautens a little bit, therefore it is not desired to shrink Ceconite at 350 degrees because the dope will add a little more tautening.

                        This difference can be used to good advantage. On an Aeronca 7AC wing it is entirely possible to crush ribs when doing a 350 degree shrink on Polyfiber. (The FM says you can't do it, but I have proven to myself that the FM is wrong) Ergo, I prefer to use Ceconite on the Aeronca with those light-weight, crushable ribs.
                        Best Regards,
                        Mark Julicher

                        Comment


                        • #13
                          Re: Ceconite covering process discussion and Nitrate/buterate dope

                          For those who haven't read the other related threads, I have the RH wing off of N95598 at this time and working on a fabric patch job after removing the wing tank and replacing a rusted rear wing attach fitting. I have two fabric patches in work... Theres some discussion earlier in this thread and some on another thread.

                          Here is a status report on the upper wing surface patch after this weekend.

                          Since the patch spans three rib bays, I am doing a baseball stitch spanwise along the leading edge and aft edge of the patch. We were sure to peel back the existing dope far enough so that the stitches were fabric-to-fabric and not sewing through the existing dope finish. On the outboard edge, the existing fabric was cut right up to the outboard rib (#3) without disturbing the existing fabric attachment on this rib. In my case, the previous fabric installer used aluminum rivets so I will retain this method for securing the new patch to the ribs. But that's a later step. After consultation with my I.A. we decided that I will extend the new fabric patch past this rib by 2 inches. The edge of the new fabric will be sewn by hand (zig-zag) to the existing fabric. I will also add rib-stitches to this rib later between the existing fasteners. On the but rib end, no stitching is needed because I can get a good solid structural glue joint (Super Seam Cement) of the patch with a 3 inch overlap on the but rib.

                          As you can see by the photos, I had some pretty good help at the beginning... not without some horsing around. This photo is three generations, our son, my wife, and her dad. Pretty cool. They helped get all four corners stitched. Then it was all left for me to finish. It really isn't that slow if you keep after it and don't let yourself complain. It is actually fun. I once got frustrated with a rat's nest of a not I created. So I walked away, took a break, then came back awhile later and the knot came right out. I found that the recommendation of coating your sewing thread with beeswax is a very good suggestion. It seemed not only to keep the thread from tangling as bad, but it also seemed to help the stitches stay tighter until tied off. The most difficult seam was along the outboard edge of the rib because I had no access to the underside. I learned that if you'll pre-poke your holes it will make your life much easier and your stitches will come out a lot more uniform. You can see in the pictures, we tried to allow some slack in the fabric to account for shrinkage to come later on. The book says you will get approximately 10% shrinkage.

                          After all the attachment was done... time to shrink. Iron setting 225 to start with.... I found that the iron's heating element cuts on and off... and at 225 F, you're right on the borderline of getting any shrinkage to occur at all. When the element would click on, I noticed shrinkage happening. So I took my time and went over the area multiple times at this setting until I was satisfied that things were shrinking at a uniform rate. Then I proceeded to bump up the temperature a little at a time going over the area a few times at each setting until I got up to the 240F. This helped assure even taughtening all over. Finally at 240F I spent a good deal of time to make sure every square inch of fabric was thoroughly attended to. At this point the fabric and all the stitches were taught enough to bounce a coin as they say.

                          On to the next step... first coat of nitrate (non-taughtening) dope. I used the green-tint version. There is also a clear type, but the tinted is recommended to see where your coverage goes. It is not just about coverage however. The main intent is to get PENETRATION. You want the fabric to become impregnated with the nitrate dope. So you find that once you start brushing it into the weave of the fabric, you will learn and see how the fabric absorbs the dope. It takes a firm pressure on the brush for this to occur efficiently. You want to get the stuff brushed on and into the weave but to do so with minimal strokes. Too many strokes and it starts to become tacky and leaves brush marks. The brush technique takes practice to get down, but you can pick it up pretty quick. I think I will have a few brush marks to deal with, but I think I was starting to get better toward the last. Some folks say you can spray this first coat instead of brushing. Maybe I am old-school but my dad brushed this coat and had good results. So that's how I am doing it.

                          By the way... it just occurred to me that on the exact one year anniversary of Dad's passing I was working on an airplane as he taught me. For what it's worth, that feels pretty good... or at least is the next best feeling to having him here with me.

                          So here's the photos...
                          Attached Files
                          Last edited by barnstmr; 02-23-2012, 18:25.
                          Terry Bowden, formerly TF # 351
                          CERTIFIED AERONAUTICAL PRODUCTS, LLC
                          Consultant D.E.R. Powerplant inst'l & Engines
                          Vintage D.E.R. Structures, Electrical, & Mechanical Systems
                          BC12D, s/n 7898, N95598
                          weblog: Barnstmr's Random Aeronautics
                          barnstmr@aol.com

                          Comment


                          • #14
                            Re: Ceconite covering process discussion and Nitrate/buterate dope

                            why not go all the way back so you do not have a noticable seem in the bays? stitch can be hidden by one extra wide tape over the rib.

                            Comment


                            • #15
                              Re: Ceconite covering process discussion and Nitrate/buterate dope

                              good idea Mike... will try that on the bottom. I guess I got caught up in trying to minimize the cutout area. Always learning... thanks.
                              Terry Bowden, formerly TF # 351
                              CERTIFIED AERONAUTICAL PRODUCTS, LLC
                              Consultant D.E.R. Powerplant inst'l & Engines
                              Vintage D.E.R. Structures, Electrical, & Mechanical Systems
                              BC12D, s/n 7898, N95598
                              weblog: Barnstmr's Random Aeronautics
                              barnstmr@aol.com

                              Comment

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