Fuselage Stretching/Shorting

[Hawkeye's Hobbies]

A couple of you guys must have had the same thought at once! I received two emails asking for me to provide them with my technique within hours of each other. So here is a recap of how I mate fuselage plugs together.

Going back to my KC-777 project, I shortened the fuselage both fore and aft of the main wing section. Cutting along panel lines doesn't always facilitate two flush and true mating surfaces that will keep the fuselage square.

I start by punching out some alignment gussets using a single hole punch that I picked up at a craft store. For this one I used a "diamond" shaped punch. I keep several shapes in a tin on the bench, you never know when one is needed as a gusset or shim.

I cement them around the inside of the fuselage spaced apart. I do the fuselage halves separately, using the flat bench as a jig to keep the fuselage as square as possible.

Once the two halves are assembled then you can mate the two halves together just as you would a normal build. I test fit frequently to check for alignment issues.

Some builders use jigs, I use the model, the bench and a ruler to make sure I am keeping things squared up. Like I said cutting along panel lines doesn't necessarily mean you'll have to exacting ends to mate together. A gap is always possible. Here is one in the forward fuselage...note the "teeth" of the gussets. The spacing of the gussets allows one to move the fuselage into correct alignment during the bonding process. Having a solid gusset will cause it to be harder to work the parts into alignment.

Since I prefer to weld with solvents for greater strength, I filled the gap with strands of stretched sprue bonded in place with solvent. They lay across the gussets and the fuselage sections. When they are in place and allowed to cure, I sand them flush. Any large gaps are given another application of sprue and solvent, small imperfections are touched up with putty.

Inside view:

I use to do this process using nothing but CA and fillers. Through experience I found the structure to failed at the slightest impact or it would crumble apart over time as the putties and CA shrunk and dried out. Solvent and sprue welds the parts together forever, forming a stronger flexible bond...just as one gets from welding two pieces of steel together.

This method also gives you a continuity in surface texture when rescribing panel lines. Sprue can be left for prolong periods without the hardening issues one experiences with CA. CA continues to harden as it cures, sometimes making it impossible to shape and sand without damaging surrounding surfaces in the process. I've also found it much easier to do modifications after the fact. Such as cutting in an opening door or a window. If the area where the opening was to be placed, you'd find it very difficult to do it where CA was the primary filler and bonding agent. Also sanding and grinding at CA has inhalation risks from particulates suspended in the air. You don't get that with styrene.

Questions?

[Atlant]

Gerald,

Thnak you so much for perfect tutorial!

Leo.

[oldHooker]

Gerald,

Thank you very much from me too; it certainly does clarify things and eliminates much trial & error! Thanks again! :)

Take care,

Frank

[Hawkeye's Hobbies]

Wing fairings!

Cut those out so they remain with the center section of the wingbox if your project requires you to cut within that area.

You'll be able to "feather" them into the fuselage much easier than trying to add them on later as separate pieces. The front one in this project is an easy one. The aft will require some relief cuts and reshaping to remain plausible.

[Jennings]

I'm always amazed at peoples' engineering methods Me, I'd just glue a strip of scrap sheet styrene around the inside of the joint and glue away. In point of fact, if the plastic is thick enough on the fuselage parts, I just flood it with liquid glue. I've been chopping airliners for like 30 years now, and have never had one split open on me yet

Love the KC!

J

[Youngtiger1]

Gerald,

Thank you for sharing that with us. This is an awesome idea and great way to file gaps. Especially large gaps, and it will keep them strong. You are correct about CA every time I tried it to fill gaps, it would get harder and then the sanding process will damage the detail around it but would not do anything to the CA... Well, just one question, would any solvent do during the bonding tech? TIA.

Mike

[Hawkeye's Hobbies]

I use Weld-On #3 or Tenax, but most other solvent cements should do as well. If they are not as HOT as the Weld On and Tenax then the process might take a bit more time to get the penetration and curing complete.

[Youngtiger1]

I use Weld-On #3 or Tenax, but most other solvent cements should do as well. If they are not as HOT as the Weld On and Tenax then the process might take a bit more time to get the penetration and curing complete.

Gerald,

I don't have either of the above that you mention, but I know where I can get Weld-on. Again, thanks for the cool tip.

Mike