Part of the RC Airplane Building & Repair Center
Covering is the point where a collection of sticks finally starts looking like an airplane, and it is one of the most satisfying parts of a build. I have also learned that a good finish begins long before the covering iron is plugged in. Straight structure, smooth wood, properly shaped edges, clean adhesive joints, and a dust-free surface matter far more than trying to chase every flaw later with extra heat.
This guide is part of the Building & Repair Center.
Choose the Covering for the Airplane
Heat-shrink polyester film is common on sport airplanes because it is light, fuel resistant when sealed correctly, and available in many colors. Lightweight films suit smaller models. Fabric and painted systems are often chosen for scale airplanes or large models where durability and appearance outweigh added weight and labor.
Use the covering manufacturer’s adhesive and shrinking temperatures. Different brands—and even different product lines—can behave differently.
Prepare the Structure
- Finish the major shaping before final sanding.
- Fill only where necessary with a lightweight material compatible with the covering.
- Sand progressively until joints and transitions are smooth.
- Remove all dust from the wood, corners, and building area.
- Inspect for loose glue joints, unsupported film areas, and sharp projections.
Covering will hide color differences in wood, but it will not hide a ridge, dent, glue bead, or rough leading edge.
Plan the Sequence
Work from the least visible or lowest surfaces toward the most visible. On a typical wing, that often means bottom panels before top panels so overlaps face away from the airflow and are less noticeable. Plan seams over solid structure where the adhesive can bond securely.
Cut pieces with a reasonable margin. Too little overlap creates weak seams; excessive material makes corners bulky and hard to finish.
Tack, Seal, Then Shrink
Position the material and tack it at a few points before sealing the perimeter. Work gradually to avoid trapping wrinkles or pulling the piece out of alignment. Once the edges and seams are secure, shrink the open areas using the recommended temperature and method.
Do not use heat to force a warped structure straight. Shrinking one side aggressively can introduce a twist. Support the part on a flat surface and shrink opposite sides in a balanced sequence.
Hinges, Openings, and Edges
Keep covering and adhesive out of hinge slots, threaded holes, bearing surfaces, and glue areas that must remain bare. Seal around servo openings, landing-gear blocks, wing-bolt holes, and fuel-exposed edges. Use a sharp blade and protect the wood; deep cuts become stress risers.
Fuel-Proofing and Final Inspection
Glow and gasoline residue can work under poorly sealed seams. Follow the covering and finishing-system instructions for fuel proofing around firewalls, tank compartments, cowling openings, and exhaust areas.
When I finish covering an airplane, I go back over it as though I had not built it myself. I recheck hinge security, control clearances, wing alignment, and center of gravity. Covering and paint add weight, sometimes farther from the centerline than expected, and a beautiful finish is not useful if it hides a loose hinge or leaves a twist in the wing.