How do I apply silkspan to wings? *Edited 2*

I thought the old bearded tattooed guy was gonna play some Iron Maiden music. Silly me.

Watch Roberts video. That is one gentleman who knows his stuff!

If I recall, your a younger modeler. When I was younger, my parents wouldn't let me use dope. I would thin white glue like Elmer's glue to a consistency just thicker than milk.  Cut your silkspan 2-3" larger than your wing. Start on the bottom first. A wing that has center sheeting in the middle of it works easier as this allows you to split the sheet and work one side at a time. You can cover from the center sheeting to the last rib before the tip.

        Sanding using fine sandpaper, knock down any edges such as areas where the rib meets the leading edge and trailing edge. Slightly round all ribs by holding the paper on a angle leaving little to no square edges. If the wing has center sheeting, sand the edge that faces the open bay on a slight angle as well. Any sharp edges that are raised can cut the silkspan later when the material shrinks. This is the reasoning you need to smooth out edges.

         I would brush the thinned white glue on the perimeter of the wing with a artist brush. Brush it on the leading edge, trailing edge, center sheeting and the edge of the last rib. When I would treat the wing tip as a separate pieces I would leave the material about 1/2" past the last rib. Wet the silkspan, with the wet piece in your hand unfold it and place it across your chest onto your shirt. This will dry the silkspan so it's not sopping wet but leave it wet enough for it too shrink later. Take the piece and lay it onto the wing panel your covering. The white glue on the perimeter will be enough for you to begin tacking it down and smoothing it out with your finger. Silkspan has fair wet strength. You can lift it as needed to remove wrinkles and if needed, you can apply more glue under it with the artist brush smoothing it with your finger. Just try to pull wrinkles by starting in the middle and working out to the edges in both directions.

       At the last rib before the wingtip, begin to bend the edges over the last rib by applying more white glue to the edge of the wingtip folding it over the rib. You can do the other half of the wing on the same side just overlap the seam in the middle by about 1/4". Set it aside until it's dry and do the same on the topside. The wingtips can now be done after all is dry. Just maintain a 1/4" overlap. I prefer the wet method of installation but one can install it dry and spray water over the covered model later if you don't care to work with it wet. I prefer it wet because it sticks down better when it's wet and it relaxes the material.

        When the wing was completed, my dad would apply the dope onto the silkspan. Dope is what shrinks any wrinkles out of the silkspan that the water didn't and maintains it taught. Generally, this requires 3-4 coats of CLEAR dope. When brushing, brush just the leading edge from the center out to the tip staying only on the hard surface. Don't do the open bays yet. Do the same for the trailing edge as well. Once these areas are done, brush the open bays the same direction as the ribs are. If you brush from the center out (Span wise) the dope if forced through the material and will puddle on the inside of the wing against the rib so brush the first two coats in the open bays the same direction the ribs are.

          A good tip is that when your all done coating the wing, go back over the ribs only just before your ready to clean up. Build up the coats on top of the ribs by just laying a brush stroke over them one more time. Do this at the edge of the center sheeting as well. These areas when sanded are the edges which are most susceptible to being cut through so it never hurts to add more dope in these areas.



I generally don't sand the first application of dope. I sand the second coat with 320 paper and I don't sand on the ribs or wherever any edges are raised. Never sand too much on these areas as it will cause the silkspan to split at a later time. Sand the leading edge, trailing edge and just feel the areas for bumps and rough spots. Sand only enough to knock any high spots off. Open bays will only require a swipe with the paper. Continue to apply more dope sanding if only needed. A soft squirrel hair brush works well . Keep applying dope until the surface looks shiny.

           You didn't mention what kind of dope you have or are using. I prefer Sig dope. Butyrate dope is fuel proof and the nitrate version is not. All colored dopes are butyrate which is the fuel proof version. Nitrate can be used for applying the first few coats but if the model is to be used for nitro engine use, it needs butyrate dope as a finish coat to fuel proof it. You can apply as much CLEAR dope as you need to. Clear is the lighter dope while colors are heavy. You only need one to two coats of colored dope. Sig dope is also the easiest dope to use for the beginner. It dries slower than any dope currently available which allows one to brush it without dragging.

         Your dope needs to be thinned 50/50 for brushing the color. You also need to work fast. The nice thing about Sig as I mentioned above is the fact that it dries slow which equates to when you overlap your brush strokes, it will look bad at first but after a 1/2 hour it will all smooth out and blend in better. Ken

Very informative and well written.  Thank you Ken for the write up.

One thing I should've made mention of is the warping that can occur. White glue has water in it therefore your essentially brushing water onto the wing panel. This can cause leading and trailing edges to bow. Once you covered the bottom of the wing panel, you can within minutes begin to cover the top panel. Outside working allows for faster drying but in the sun especially, the top panel if laid flat can dry too fast. The water is now trapped under the wing and the top dries and the bottom is still damp. This induces a warp. I like to hang the wing by the tip. This way both sides evaporate evenly. This same practice goes without saying when using dope as well. While dope is solvent based, it shrinks as it dries. This too can cause weak trailing edges to bow. The nice thing about dope is that doping more coats on the underside of the bow can pull it back. In addition, one can also dampen the wing panel and use a heat gun to tweak it back.