SPA Modeler

Duke Maddog wrote: ↑Tue Sep 15, 2026 3:34 am Having built a good number of 1/72 scale biplanes; I have achieved the most success with stretched sprue. Other types of threads have always caused me to break the wings and sometimes the tails of any aircraft I try to rig. Stretched sprue has always served me best.

Impisi wrote: ↑Tue Sep 15, 2026 12:55 am Well, I'm late to this party, but perhaps can tell what I did with the 1/72 biplanes I did last year or before ...

I don't think those thin threads provide any real structural stability for a plastic model, let alone hold the wings in the correct position. Here is the method I used:

I cut foam "wedges" to match the angle between the outer struts and the lower wing. I drilled holes lengthwise into the struts to insert thin wire for added bonding strength. I then drilled corresponding holes in both wings for the struts and glued the outer struts to the lower wing using the wedges. Since I had glued wires into the struts, I was able to slot the upper wing onto them and fix it in the correct position. Next, I fitted the inner struts and glued them to the fuselage. This established a solid, accurate alignment between the two wings.After that I removed the upper wing and continued with painting and such.

For the rigging, I drilled holes wherever necessary—drilling all the way through the wings. Then, I painted and assembled everything. I threaded the rigging lines through the wings (top and bottom), glued them on one side, and then glued them on the other side while keeping them under tension. Any protruding ends were trimmed, lightly sanded, and painted over.

I should probably mention that I’ve built ancient biplane kits from manufacturers like KP and APEX—kits where fit and precision were hardly a given.

you can find the outcome at my space at scalemates, the Polikarpov R5 from Apex is one example

oh, and I forgot to mention: I used a line called "Dino Ultra", that's a 0.08mm fishing line, which I painted after after the rigging. this line would shrink with heat, so you can tighten it using a heat gun, but I don't know if it is available outside Germany.

Impisi wrote: ↑Tue Sep 15, 2026 12:55 am Well, I'm late to this party, but perhaps can tell what I did with the 1/72 biplanes I did last year or before ...

I don't think those thin threads provide any real structural stability for a plastic model, let alone hold the wings in the correct position. Here is the method I used:

I cut foam "wedges" to match the angle between the outer struts and the lower wing. I drilled holes lengthwise into the struts to insert thin wire for added bonding strength. I then drilled corresponding holes in both wings for the struts and glued the outer struts to the lower wing using the wedges. Since I had glued wires into the struts, I was able to slot the upper wing onto them and fix it in the correct position. Next, I fitted the inner struts and glued them to the fuselage. This established a solid, accurate alignment between the two wings.After that I removed the upper wing and continued with painting and such.

For the rigging, I drilled holes wherever necessary—drilling all the way through the wings. Then, I painted and assembled everything. I threaded the rigging lines through the wings (top and bottom), glued them on one side, and then glued them on the other side while keeping them under tension. Any protruding ends were trimmed, lightly sanded, and painted over.

I should probably mention that I’ve built ancient biplane kits from manufacturers like KP and APEX—kits where fit and precision were hardly a given.

you can find the outcome at my space at scalemates, the Polikarpov R5 from Apex is one example

oh, and I forgot to mention: I used a line called "Dino Ultra", that's a 0.08mm fishing line, which I painted after after the rigging. this line would shrink with heat, so you can tighten it using a heat gun, but I don't know if it is available outside Germany.