Can anyone help me avoid landmines on the Koster SSW D.IV?

[melsharkskin]

I've been building Koster Aero Enterprises kits almost from the beginning. Bill Koster, who designed some of the finest classic injection kits for the major manufacturers for years, has had his own side business for years, and he's winding it down now. He gave us subjects in mixed media that were not available in any media, always in 1/48 scale. Even after the big injection makers followed Bill's lead and made mass market kits, they never matched his artistry and accuracy.

Bill just sent me two kits for upcoming articles, one of which was his Siemens-Schuckert Werke D.IV. Last time I built this kit, it had vacformed wings. This one has resin wings. I remember it to be a joy to build ten years ago, but putting heavy resin wings on a vacform fuselage and scratchbuilt struts (I'm planning on using either Strutz, which I have no experience with, or Aeroclub extruded strut stock, with which I do have considerable experience.)

My question is, has anyone built this "modernized" version of the SSW D.IV? How best to attach the wings, since solvent cements are out here and CA may not have enough holding surface for the weight. I consider 5-minute epoxy a bond of last resort on any project. And are there any other tricks, such as the unique mounting and framing around the engine, inside the cowling and four-bladed prop? I can't wait to put it in Jasta 15 colors.

In a slightly related matter, Bill also sent me what I believe was his last copy of the outstanding KAE Sopwith Triplane kit, which was my first vacuform, and which I plan to write an article about showing those who have never built a vacform that these models can indeed be made to look as good as an injection kit.
Nobody but Bill could engineer a triplane that was accurate enough for master modelers, yet simple enough for one who had never built a vacform, and I was in that category when I built it. The secret to its simplicity is in the ingeniously basic wing jigs Bill included on the sheets for the plastic parts. Which begs the question: Why have injection kit makers never bothered to put two or four more simple parts on a sprue with all the other stuff? I'm referring, of course, to jigs. It would cost them virtually nothing, and would in time help draw in those modelers who are frightened of planes with more than one wing.
TOM

[StephenLawson]

There have been a couple of vacuforms / resin kits that I built a box out of the resin runners the parts came on. (two squares or rectangles with connecting resin braces.) These are pinned and cyano-glued at corners. It is made to slip inside the fuselage and serve as a connecting union for landing gear and cabane struts.

[Paul914]

One thought that comes to mind is to use the 5 minute epoxy to reinforce the inside of the vacuform fuselage where the struts attach to give it some stiffness and hold the weight of the resin wing without deflecting. Do not use a polystyrene based resin as a filler / reinforcement because they contain styrene monomer, which will definitely dissolve the vacuform plastic. Perhaps you could use a contact cement to attach the vacuform parts to the resin or injection molded parts? If the solvent in the contact cement attacks the vac form piece, the epoxy is there to back it up and some squadron putty can fill the gaps. You can test the cement on a scrap corner of the vacuform material. Vacuform material is typically a low molecular weight polystyrene, vs. the high molecular weight polystyrene used in injection molded pieces or extruded forms, like strut profiles - which is why it is more susceptible to solvent attack.

On a side note, a styrene cement can be made by dissolving low molecular weight polystyrene in a solvent like toluene, methyl ethyl ketone (MEK), or acetone. Testors liquid plastic cement is based on MEK, so you can thicken it up as desired. You can get the consistency you want by dissolving more polystyrene to make it thicker. A good source of low molecular weight polystyrene is foam "packing peanuts", the kind that 'crunch' when you tear them.