Joint methodologies

Discussion in 'General Card Modeling' started by Larry Marshall, Sep 6, 2006.

  1. In another thread, rmks2000 said:

    I was looking at this. From what my naive eyes tell me is that there are 3 distinct methods for joining fuselage segments. I'm sure they each have fancy titles but I don't know them. What I see are:

    1) lots of little tabs that fit inside the preceeding segment

    2) butt-joints with an internal joint strip.

    3) butt-joints where a thick former supports the joint internally.

    It seems to me that the Marek kits have both 1) and 3) type joints (talking about the Pfalz kit here). When you say "ring and former" are you talking about replacing 3) with 2)?

    What are the tradeoffs here? I'm starting Rob's (FG) FJ-1 and it seems to me that removing the little tabs and replacing them with an internal ring might generate a smoother fuselage. What say you?

    Cheers --- Larry
  2. shoki2000

    shoki2000 Active Member

    I would modify this list as follows
    2) one former and a joining strip - "ring and former" method mentioned by rmks2000
    3a) butt-joint with two formers (one per segment)
    3b) one thick former which fulfills both function - former and joining strip

    Now advantages/disadvantages
    1) might work with small model but it creates a very pronounced bump on the connection

    2) I preffer this one since it provides the smoothest connection

    3a) needs lots of cardboard to laminate and both formers have to be identical otherwise you will end up with little bums and ragged edges

    3b) never tried that but I would say cutting 2mm card can be very tiring on the fingers
  3. rmks2000

    rmks2000 Member


    Yes, I meant replace 3 with 2. Traditionally, I believe that most Polish models used the butt joint method, while the German kits used the joiner strip method(using a single former). Now, many of the Polish kits also use the joining strip method. Michael gave a very good explanation of the strengths and weaknesses of the methods. You may even find that a combination of them may be warranted depending on the various factors such as complexity, visibility, build speed, etc. In general though, I think that the joining strip method gives the best results.
  4. John Griffin

    John Griffin Member

    I like the 2-former method personally (butt-to-butt or bulkhead-to-bulkhead method). If you have a precisely designed model, the fit will be just as good as with a former-and-strip join. And anyway, if you do get a kit that is designed for butt-to-butt build, but you want to do the strip join type, you can toss one former, sand a *tiny* bit off the other former's edges and use copier paper to make a narrow join strip and do it that way. Just test fit everything before gluing.

    *Tiny* because the copier paper strip is very thin (being paper, not card). I use my wife's emery board nail file thing.
  5. rmks2000

    rmks2000 Member


    I've only built one butt joint model but can say that it can take a lot of abuse. I ended up with some 'hourglassing', but I get that sometimes with the joining strip method also. I guess I just am not as precise in my fitment as I would like.

    While we are on this topic, Do you prep the former with CA before sanding so the edges don't fray?
  6. Do you also substitute 2 for 1? Method 2 just makes so much sense to me and while I don't have a paper shredder, it doesn't seem like rocket science to cut strips :)

    I guess that generates another question. As I read through the forums I found the idea of just using straight strips as well as using strips cut to the curvature of the fuselage sections. The later also made sense to me but is that overkill? Unnecessary because typically the join strips are wide enough that slight variations in their overlap doesn't matter?

    In any case, I think I'm going to try it on this FG-1 Fury and see what happens.

    Cheers --- Larry
  7. John, good points about the 2-former method. Those nail files are handy buggers but I learned long ago to buy my own :) I have them in several grits.

    Cheers --- Larry
  8. Warning....advice from a rookie should always be suspect:

    I would suggest using some thinned Duco cement for this. First, it's far less toxic. Second, it's far less expensive. Third, it dries nearly as quickly (particularly if thinned with acetone). Fourth, and this is for the's cellulose-based :)

    Cheers --- Larry
  9. Bowdenja

    Bowdenja Active Member

    My Two Cents............

    I will more times than not make separate joining strips for my model builds......... this suggested when I first started and that's the way I like to build. If a model has bulkheads then I will fit them in after gluing the parts together and glue it place at that time.

    I built Rob's Fury both ways...........attached and separate strips, at the scale 1/48 there really is not much difference.

    Now on anything above 1/48 scale attached strips are NOT the best way to join because it does show a pronounced step in the appearance of the model sections.

    I built John's Tempest by converting it to strips and it did great........

    so it really boils down to what ever you are accustom to............. only to the point that sometimes you MUST use butt joining because of the design and fit of the part..............

    There really is no right or wrong way of joining parts...........just whatever you like best and looks best!

  10. 46rob

    46rob Member

    My experience with attached tab strips or separate joiners, shows little difference, other than the edges are a bit better hidden with joiner strips. When you build those tip tanks for the Fury--they'll look much better using joiner strips...the fuselage, being rather large, can go either way. Most of us use water based white glue for the models, and when you do, the moisture in the glue will slightly expand the paper, and then shrink it as it dries. This adds to the illusion of curving, giving better transitions between the elements. If you were to cut apart a model that was joined with either tabs or strips, and laid the sections over a printed page, you'd notice subtle differences in the shape, and the parts would have a bit of compound curve to them. I've noticed this phenomenom on nearly everything I've designed, as one of my techniques is to build the unmarked model, and then pencil in the panel lines, flight controls and access panels that I want to show on my model. The cut-apart sections never exactly conform to their original shapes.

    Using too much glue around bulheads will give that "hourglassing" as the paper will shrink as the glue dries. To that end--since I'm no longer designing for FG, and no longer have to follow their protocols (like"NO bulkheads"), I purposely design my bulkheads slightly undersized, as they are soley there to assist the modeler in achieving the correct shape. Upcoming models will give the builder the option to use tabs or strips, too. Now I can add cockpit details, more wheel well details, make 3-d struts and all the other things that make FG models simple to build, but lacking in authenticity.
  11. John Griffin

    John Griffin Member

    sanding formers

    No, I generally don't use CA anywhere. I hate it because I always get my fingers glued to the model! And it stains and shows thru the skin. But as for using it in a former, I would think that it would make it harder to sand down, but I might try it next time. The formers do tend to get a bit fuzzy around the edges, but I haven't really found that I need to take off too much anyhow, especially when using home-made paper strips. Good suggestion though, I will use it.

    BTW, regarding the need to 'curve the strips... I just wrap the copier paper strip (like from a shredder) around the BH, then with scissors just put in some cuts around one side, to allow that side of the strip to be 'coned in' slightly to fit into the smaller fuselage cylinder section nicely. It's sort of like tabs but cleaner and fits great.

    Here's another thing I've learned, while building 'too fast to do it right'...
    If, when doing a BH to BH build, there is a gap in between the two BHs that should butt against each other, I put Elmer's glue on each BH, then fill the space between with a bit of tissue. This isn't usually needed except when I'm doing a 'rush' build (a quick and dirty). It gives a solid joint.
  12. Really? On mine, sections 2 & 3 (most of the nose area) have tabs. More odd differences I guess.

    Since you use Duco, do you have occasion to use acetone to loosen a joint? It would seem an advantage to Duco sine acetone doesn't seem to affect most inkjet printer inks and it won't expand paper like water will.

    Cheers --- Larry
  13. This makes good sense. Hadn't thought about the glue effects. I think I'm going to use your FJ1 design as a 'guinea pig', doing the front half of the joints as you've designed them and the rear ones with join strips. BTW, I built the wings and stab last night and they went together beautifully. I guess that comes as no surprise to you :)

    Cheers --- Larry
  14. 46rob

    46rob Member

    It's a fairly nice build--but if you really want a sweet one--try the Hunter next. Those graceful lines take on a life of their own as the sections glue up. BTW--all my models are designed to use 67 pound paper, so using it gives the best results. It's cheap and readily available. I use the Wausau Bristol, from Office Max for all my prototyping.
  15. Ah...the hard sell, eh? I just downloaded it :) Are there other FG models that are your designs?

    Cheers --- Larry
  16. 46rob

    46rob Member

    A-7 Corsair II, F-100 Super Sabre (both also free in the Parts bin in the forum) F2Y, DC-9 and A-4 Skyhawk. I also completely redrew the Cougar and the 'regular' size only, though. I've also done the T-33 (free in the Parts Bin, again) and the P-80, along with some ground supprort equipment. Currently in work are the XF-90, A-3 and F-105. Slow work, because I only devote an hour or two per day to the designs.
  17. lizzienewell

    lizzienewell Member

    I have a fourth method but it only works if designing the models. This might be the same as Carl's method #4.

    4) Skin over frame. The frame is built completely without skin. Then furring strips go over the frame. The skin attaches to the furring strips. The skin overlaps itself. The furring strips follow the shape of the frame rather than the seams of the skin and the skin seams almost seldome align with joints in the frame.
    I think that this method gives a smooth profile and that it produces a stronger and more realistic model. It reduces hourglassing because the skin is stretched on furring strips rather than on the formers. The furring strips usually run laterally. I copied this from kayak design.

  18. Ah...I guess the egg on my face is due to my blitzkrieg approach to getting into card modeling. I downloaded both the A7 and F100 as I was running around the site trying to absorb all that has been written. I'm only now getting to know some of the names and talk to some of the people like here so I didn't associate you with those models. I really like the A7.

    As for the rest, I now own all but the P-80 (can't find any evidence/source for that one). I was really happy to hear that you'd done the DC-9 as it had caught my eye but I was unsure about how it would build.

    The Panther is my favorite jet so that's a big plus. Are you aware that the Photo-recon version has a note dropped on top of one of the wing panels thanking someone for the wing tanks. It makes it unbuildable without doing some Photoshop work.'ll give my credit card time to cool down :)

    Cheers --- Larry

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