Beginner's guide to fuselage assembling

Tools 'n' Tips Article by Steve Wilder in 2002 

 

Over the last two years, I have learned numerous tricks from several on-line modeling websites that have helped my model building tremendously.   Although I am by no means an expert, I have learned a few tricks that I find useful, and combined with a little patience, some readily accessible tools and some imagination, I have learned to improve these skills, and I hope to pass them on to you.  

This is an attempt to offer some practical solutions to help modelers create more realistic aircraft fuselages.   It is not the end-all and be-all of guides.  It is a description of the way in which I build my fuselages.   I am always open to further suggestions, and love learning a new trick that will help improve my building.

By far, the most common problem that arises in the building of a fuselage (I’ll leave the problems associated with painting that fuselage to another article) are the seams that occur due to a mismatch between the joining pieces.   The fuselages of most model aircraft consist of two pieces – a left and right half that join at the top of the spine and the bottom of the belly of the plane.   One of the goals (if not the goal) of building a model is to create a representation of something that looks like a smaller version of real thing.  

 

 Nothing destroys this attempt more than a visible fuselage seam.  There are other things as well – glue on the clear parts, poor paint job, etc, but like I said that is for another article. 

 First let’s look at some of the tools necessary to make a good-looking fuselage. 

 

Tools of the trade – What you’ll need 

  • A good working surface (just a cleared off kitchen table will work)

  • A good cutting surface (I use an old wooden kitchen cutting board.   The key here is something that gives and that you can cut into.    Glass, for example would be a very poor cutting surface)

  • A comfortable knife, scapel, etc with several new blades

  • Glue (I’ll go over the merits of various glues here in a minute….)

  • Modeler’s putty

  • Q-Tips

  • Toothpicks

  • Fingernail polish remover (!)

  • Clothes pins

  • Various other clamps available at art stores, hardware stores, etc (paper binders are also great)

  • Gunze Sangyo’s Mr. Surfacer – not really necessary, but a great tool once you learn how to use it…

  • A nifty little glue applicator, carried in some modeling stores, consisting of a long, thin glass tube and hypodermic tubing at the end.     More on this later….

  • Various grades of sandpaper

  • Various grades of sanding sticks

  • Patience

  • A good beer-  OK, not really necessary, but often very helpful.    A nice, cool Shiner Bock brew has kept more than one “difficult” model from flying into the nearest wall….

 

A Quick Discussion about glues… 

– everyone has their preferences as to what glues they use and why.   Saying that one type of glue is the best glue, is really nonsensical.    The reason is because the various glues available to modelers each have their good points and their bad points.    The basic glue types are as follows –  

  • Traditional  “tube” glue that we all used as kids

  • Liquid “welding” glues such as Testor’s, Ambroid’s Pro Weld, Tamiya and Tenax.

  • CA, otherwise known as Cyanoacrylate

  • Clear parts cement –

  • Epoxy

Tube glue is actually not as bad as one might think.  It has a thick consistency, so that it can hold parts together while they are drying.   The downside to the glue is that it takes forever to dry, isn’t super-dooper strong, and has the famous problem of leaving “glue strings” wherever it meets plastic.  The glue strings are caused by the tube of glue being old...when you get glue strings it's time for a new tube of glue......and hope the stock at your local hobby shop is fresh...or the new tube will produce glue strings as well.  Tube glue also has a bad tendency to find its way to the nearest set of fingers and leave smudge marks all over your kit. 

Liquid glue – my most commonly used glue.   Personally, I use Testor’s Liquid Glue, as I find that the Tenax brand glue dries very quickly.   This glue actually melts the plastic and welds the 2 pieces together, proving for a great seam.   The biggest advantage of liquid glue, however, is its “oozing” properties, which I will discuss below. 

CA – a great glue, and your only option for gluing brass or resin pieces.   CA comes in various viscosities (thicknesses) – thin  (water like) medium (similar to tube glue) and a thick gel.   There is also a vapor-less CA that is supposedly OK to use for gluing clear parts, although I’ve never tried it.   CA has an interesting property in that left alone, it will usually cure in anywhere from 30 min to according to the label – 2 hours, depending on the temperature, humidity, alignment of the planets, etc.   There is a nifty little product, however, called CA accelerator which will cut that drying time down to about 2 seconds – literally.   Just spray the stuff on, and voila – it’s dry.   While CA is great for quick job, I don’t recommend it for major seams, such as joining two fuselage halves together.   The reason is that while CA is indeed a very strong glue, it does not do well with sudden sheer force, such as dropping a part, or heaven forbid, a whole kit.   Many a modeler has dropped a kit on a hard floor, only to watch the two fuselage halves split right open.   Another disadvantage of CA is that because it carries such potent fumes, it will quickly fog and ruin any clear parts that you get it near.  Coating your canopy and other clear parts in "Future" before using CA will prevent the fumes from the CA glue from fogging the canopy and other clear parts.   In other words, don’t use CA to glue canopies…instead, use…. 

Clear parts cement.    Pretty much what it says it is.   Not the strongest, nor the quickest drying, but this cement does its job very well.   Another substitute that some modelers use is every day Elmer’s white glue and even watch crystal cement which watch repair shops use....dries very clear). 

Epoxy – unparalleled in its strength, epoxies still have their weaknesses.   Basically, they have to be mixed in the proper proportions (not much room for error), and they have to have something to “grab” onto.   For example, I cut out some bulkheads to fit inside of a vacuform kit I was building to add strength and to help the parts retain their original shape.   Because the inside of the fuselage half and the bulkhead were both glass smooth, the bulkhead popped right out the next day.   I have since learned to use a coarse grain sandpaper on any surface I plan on using epoxy. 

If you are looking for more information on glue, I suggest that you check out the RMS FAQ. 

 

Plastic Preparation 

Before getting into the specifics of gluing the fuselage halves together, lets discuss preparation a bit… There are several things that are advised before you begin gluing parts together.  One of these is doing research.   That is up to you to decide.  If you want to learn every little bit there is to know about a specific plane before you build, or if you just want to start building something to represent what’s on the box, you decide.   Another recommendation is that the model be thoroughly cleaned before any parts are assembled.  This is actually a pretty wise idea, as some manufacturers use a significant amount of release agent chemicals to help the plastic pop out of the mold, and these chemicals usually do nothing to help the paint you will be trying to put down later.   

Now, assuming that you are all read up about your subject, you’ve opened the box, smelled the wonderful aroma of freshly minted plastic, and washed the parts, let’s get down to the nitty-gritty.

   When I was building models as a youngster, my enthusiasm and excitement of having a new kit would usually overwhelm my urge to patiently build a great model, and I would start tearing the parts off of the tree by hand, twisting, tearing and pulling as I saw fit.   This got the parts off of the tree, so I was happy.   However, believe me here – this is not a wise idea.   Not only does it leave serious pockmarks where the plastic was pulled off, but you can also damage the part by bending or warping it.   Take your time and carefully remove each piece with either your knife or a set of wire cutters, leaving a small piece of the tree still attached- no more than 1/16” or so.    Some modelers use a special tool designed for just this purpose, and that’s fine.   Personally, I don’t think you need one of these unless you are cutting brass from a photo-etch set, but whatever floats your boat….    Once you have removed a part, lay it flush against your cutting surface, and very patiently, carefully remove the 1/16” stub that is left over.   The key here is to only cut until you’ve reached the finished piece.   DO NOT cut into the plastic that you want to finish later.    It’s better to leave some of the plastic uncut than to cut into the finished piece.   It can always be sanded off later, but cuts that are too deep must be puttied and sanded.  Removing this stub with a small modeling file works well too.

 Usually, I start by removing only the major parts – the parts that you really don’t need to know the part numbers in order to successfully build a model.   So I, for example, would cut the fuselage halves, wing pieces (two, three, four or however many pieces) and nose cone or engine cowl.   I would also cut out the cockpit tub and landing gear well, if separate.   Here’s where the fun begins.

Dryfitting 

After washing, removing and trimming the basic parts, align them up and note how they fit.   Are the fuselage halves warped?   Do the panel lines line up?   More importantly – can you install the cockpit floor or tub and the wheel well tub (or any other major pieces that belong to the interior of the fuselage) and still relatively easily close the whole thing 

up?    Do the two pieces join together like nothing is between them, or do you really have to squeeze everything with all your might to make the seam disappear?    If the former, you are in luck.   If the latter, you have some work to do.   Keep in mind that during these “dry fittings” parts that aren’t glued down often have a tendency to shift or slide around, giving you an inaccurate feel for how they might fit when you actually use glue. For example, let’s assume that you are building a 
kit with the standard left and right half fuselage with a cockpit that must be glued in.   You lay one fuselage half down on its side, lay the cockpit on top of that, followed by the other fuselage half.   When you pick the two halves up and hold them between your fingers, everything seems fine – you can hold the two halves together with relatively no pressure.  However, what you don’t realize is that when you picked the two halves up, the cockpit floor slid down at an angle, thus making it seem as though there was more room between the two halves than there really was.  A little trick I use is to try to tape the parts inside to one of the fuselage halves so they don’t move during the dry fit.  I try to attach the tape in a place that won’t affect the “thickness” of the seam, i.e. attach a tape between a cockpit tub and one fuselage half at the back of the tub, not on the side where it will be caught between the side of the tub and the other fuselage half.   In short, make sure that everything that is supposed to fit in the fuselage does indeed fit before you bust out the glue.   Nothing is more nerve wracking than to apply glue to the fuselage halves, only to realize that what you thought had fit perfectly will now leave you with a nice 1/16” gap running all the way down the spine of the fuselage.   Then, trying to pull the already stuck parts apart gets ugly - you  get glue fingerprints everywhere… well, you  get the idea.   In woodworking, the phrase is measure twice, cut once.   Modeling is similar, maybe something like dry fit twice, glue once.  

 

Now, having taking care of this, here comes the hard part – actually using glue.   Really, if you’ve test fitted everything, you shouldn’t have anything to be afraid of.   This may sound funny, but I often go through the procedure of how I’m going to glue a fuselage together
 in my head before I actually do it – several times.  You’d think I was performing brain surgery or something.    Anyway, here’s where all those nifty tools come into play.    Try to find tools that will allow you to hold the fuselage together without squishing it.   When you apply too much pressure to a fuselage, the sides often squish in, distorting the actual shape and often creating a killer gap at the wingroot.   More trouble than you want to deal with.   So, what do I do?   Well, let’s look at the first example – the Zero.   I used an assortment of 
various clothes line hangers and clamps I found at a hardware store (Sears to be exact).    I don’t use rubber bands for a few reasons – they cover up the seam I am trying to observe as I do this, plus they have a horrible habit of removing the glue from the seams (via capillary action) and distributing the glue all over the side off your fuselage.    Not good.    All of this is before I apply any glue.  I check to make sure that the panel lines are all meeting at the same place, and that the two fuselage halves are at the same level.  One little trick I’ve learned is that working in low light can often be helpful for this.   The reason is because misaligned parts are easily identified by the shadows that they cast.   For example, after I lined up the fuselage like you see here in the picture, I looked at it from the side and rotated it, like a real plane does when it rolls.    If I notice any sudden changes in the shadow as I continue to turn the fuselage, then this means that one side of the fuselage is higher than the other.   I like to use light to help me find mistakes before all is too late.    Another trick I do is to run my fingernail forward across the seam, and if it catches, then there is obviously one side higher than the other.  

 

Sometimes, you will have to make a difficult call.    If one side of the fuselage is smaller than another, what do you do?   Personally, I choose to line the fuselage up along the top seam, as this is what you will see the most.   You can try to bend the two pieces to make them fit simultaneously, but I wouldn’t recommend it.    I would either correct it later with putty, or do something I’ll show you here in a minute (build your fuselage in stages).

OK, so the kit is held together with clamps, and you are satisfied with the way things look.    Let’s get dangerous.    As I said earlier, I use liquid glue for the majority of my building, and joining fuselage halves is no exception.    If you recall, I mentioned a nifty little tool earlier that consisted of a glass tube attached to some hypodermic needle tubing.   This tool isn’t completely necessary for this operation, but I do find that it helps.   Once I look at a held together fuselage and say to myself “Perfect!   I just wish it would stay that way once I removed the clamps!” I find an old #11 exacto blade.    Using the sharp point of the blade, I carefully wedge the blade between the fuselage halves.   This will now leave a nice long hair-line crack between the two halves.    The great thing about liquid glue is that because it is so thin, capillary action pulls the glue long and far into this seam once the glue comes in contact with it.   So, using either the glass tube filled with liquid glue or a fine tipped paintbrush (don’t use the brush on the bottom of the lid – way too thick, and glue will go everywhere but where it is supposed to), fill the crack with the liquid.   If you are using a brush, be patient – let all of the glue leave the bristles and then reload with glue. Tamiya liquid glue has an excellent brush on the bottom of it's lid, which is very fine at it's tip, but also fairly long and thin to hold a reasonable amount of glue.  

Notice “ooze”

One trick I use to sometimes get things flowing is to squeeze the seam shut with the brush in the crack – this makes the line even thinner, and it squishes the glue out of the bristles.    After that, the glue should be flowing.   Because there will be multiple clamps on the fuselage, the crack won’t be too long, and that’s fine.   In fact, I build my fuselages in several steps.   I could be wrong here, but I don’t think you can put too much of the glue in.    I mean, you don’t want it all over the place, but you do want enough in there.    Once you feel that you have enough glue in the seam, gently pull the blade out.   You should start to see that magic plastic/liquid glue ooze out of the seams.    If so, congratulations!!   Seeing this is like seeing a nice thick golden crema on top of a freshly extracted espresso, or a fat thick head on top of your beer.    You have successfully joined part of the fuselage together.    Now here is where I leave it up to your discretion.   Like I said, I prefer to build the fuselage in sections – glue a few inches, let it dry and move on.    The reason for this is simple – I can watch the progress of the drying glue (I know!  How exciting!!) and not worry about what’s going on at the opposite side.    Once I glue the two halves, I try not to touch them unless I have to.     Also, if you do make a boo-boo, it’s easier to try to make the other pieces join properly.    But that’s your call.    Anyway, once you have done this, repeat and move on down the line.    I know it may take a while, but getting this seam wrong will be pretty obvious or require a lot of repair work.   Patience grasshopper….

more “ooze”

Seam Clean-up and Surface Preparation 

After gluing all of the fuselage, I usually wait a good day or so to let the glue fully cure.   Once it is dry, I begin the process of removing the plastic “ooze”.  
Assuming that all went well, the melted plastic hopefully filled in any seams that would be present.   I remove the plastic “ooze” ridge in steps with my X-acto knife until it is almost flush with the surface of the fuselage.   I then use the back of the blade to give a final  “once over” tomake sure everything is flush.   Here is the moment of truth – if the two 

parts were properly aligned to begin with, and didn’t move while drying, there really shouldn’t be much to do except go over the seam a few times with a sanding stick or some wet-sand  sanding paper.   However, not every seam will be perfect.   In fact few are, and more often than not, I end up having to fill some seam.

Again, this is another situation where you will have to use your judgment.  

If the seam is relatively minor, I suggest you take the following approach.   Using the regular thickness CA, pour out a small amount onto a yogurt lid and using a toothpick, carefully apply just a little of the glue to the seam.   As soon as you have applied the glue, spray it with the CA accelerator.   Immediately begin to sand the area down with sandpaper or a sanding stick.   N.B. – CA that has been sprayed with an accelerator hardens very quickly.   If you do not sand this down quickly, the glue will be rock hard and will laugh at your sandpaper while you sand the surrounding plastic!   Sand immediately after spraying accelerator!!

If the seam is a little more serious, you might want to consider using putty.   Here’s an example of where I decided to use Squadron’s white putty.  The fuselage for this Hasagawa 1/72 Mig was made out of eight (!) parts, not counting the nose or

 

the end where the exhausts attach.   Unfortunately, I didn’t have as much luck getting all of these parts to align as well as I did with the zero.   As you can see, I had no choice but to use some sort of filler.   I choose to use the putty over the CA, as some of the seams were rather deep, and I was worried about sanding all of that CA if it hardened too quickly.   Using the extremely helpful Aircraft Resource Center article on filling gaps without sanding in the Tools n Tips section, I filled the lower areas with the putty.   Then, I poured some of the 

fingernail polish remover in a lid, and according to the article, proceeded to wipe away the excess while smoothing the new surface.    This makes for much easier sanding after the putty dries.   To get the hard to reach areas where putty went that you can’t sand out, I just took a fresh Q-Tip soaked in the remover and it came right out. 

 

Other problems often rear their ugly head when building fuselages.   One example can be 

seen here – dimples or sink marks in the plastic.   As annoying as these are, they really are not extremely difficult to fix.    Here, I use the CA and accelerator trick to fill the marks.   As you can see, I just filled the immediate area, trying not to get any glue into the rivet detail, and then sprayed and sanded.   By the way, if you mess up and don’t get all of the whole smoothed out the first time, go ahead and try it again.  I noticed after I first sanded these that there was still a small line that had formed where I hadn’t used enough glue.  

 

Once you have properly assembled the fuselage and filled any seams or sink marks, you should pretty much be ready to go.   After filling all of the seams, I begin with a coarser sandpaper, 240 or so, and move up stopping around 1000 grade.   If the aircraft is going to be painted in a very “revealing” paint scheme, like a natural metal finish, I prefer to paint the whole plane with a primer first.    This usually highlights any mistakes that I may have made that need to be corrected before the paint goes down.    

Steve Wilder

Here are some spare reference pics..  

 

Here’s a shot after the glue has dried and I’ve removed the oozed plastic.

 

Here’s what happens when you don’t pay attention to the part as it dries…. Still don’t know how I’m gonna fix this…

 

Finish down the spine… just needs a little sanding.  BTW, I find that an old toothbrush is good to get the sanding residue out of the panel lines…

Photos and text © by Steve Wilder