(EASY) CUSTOM FIBERGLASS FAIRINGS
Whether you are customizing as ARF, assembling a kit, or building from plans, you may want or need a custom built fairing. For a measly three thousand U.S Dollars I will happily provide personal assistance. No? Well,I'll offer the secret here free if you'll read on a bit.
The example I am using is this wing to fuselage cover fairing on my scale model of a Stinson SR-5 Reliant. The wing is painted and the fuselage and fairing are silver undercoat. The model is 1:5 scale and allows some nice detail to enhance the visual appeal. The fairing wraps around the wing leading edge and extends back along the bottom of the wing for a short distance.
I use an epoxy/glass combination rather than a polyester (boat resin) for this kind of project because the epoxy is more flexible and offers a longer 'pot' life to work with.The glass is two layers of 6 oz/yd and one layer of 0.75 oz/yd on the surface to minimize the filling and priming. For what it's worth, I use a rotary cutter that is available at craft stores on a piece of plate glass to make smooth cuts easily.
'The next step involves marking the edges of the fairing with masking tape to protect the model surfaces. Then, using simple child's modeling clay, gob in the clay to form the desired fairing contour plus a little extra. You can work the final surface finish with you finger or any other handy tool. I have an Eaxcto blade with a ring shaped blade that works well for concave surfaces like this one. Final smoothing can be done with a finger dipped in 91% Isopropyl alcohol.
At this point you need to protect the models painted surfaces with a mould release. I Start with two coats of a good paste floor wax and then two coats of Poly Vinyl Alcohol (PVA). PVA is a water soluble solution that dries almost clear and the epoxy will not stick to it. The epoxy will not stick to the clay. When the epoxy sets up (24 hrs) the fairing should pop off the surface with a little prying by a thin spatula.
Lay up the two pieces of 6 oz glass covering over the edges and wet the glass cloth with epoxy thinned about 30% Isopropyl Alcohol. The epoxy soak in better and more smoothly, but, it takes longer to harden completely. While the epoxy is still wet, apply the final piece of 0.75 oz glass.
A paper towel or some toilet paper can be used at this point to soak up any excess epoxy so the surface looks slightly 'dry'. It's now time to get a can of your favorite beverage and begin the 24 hour waiting period while the epoxy hardens. The photo below shows the first two layers of glass laid over the fairing ready for epoxy.
After 48 hours, the part can be lightly sanded and primed. Add any extra elements made of scraps or whatever. I added rivets by tiny drops of epoxy, or you could use canopy glue drops. Aluminum duct tape makes realistic access panels and I add cast fake screw heads from a mould my dentist made for me. A coat of finishcolor and the fairing is done. It is more efficient to make matching fairings at the same time if more than one is needed.