What covering does
Covering protects the balsa or foam structure, adds some stiffness, and gives the airframe a smooth aerodynamic surface and color. On engine-powered models it also needs to resist fuel and exhaust residue. The right covering depends on your model’s weight, how it will fly, how it should look, and how much work you want to do.
Covering material types
Tissue
Tissue is the classic covering for light free-flight and indoor models and for traditional scale builds. It is very light and inexpensive and gives a vintage look, but it is fragile. It usually needs an adhesive and a sealing or tightening step, traditionally done with dope. If you would rather avoid dope, see our guide to model airplane dope substitutes.
Iron-on plastic film
Heat-shrink polyester films such as MonoKote and UltraCote-type products carry a heat-activated adhesive. You tack them down with a covering iron, then shrink them tight with heat. The finish is glossy, tough and generally fuel-resistant, and films come in many colors. This is what most modelers mean when they ask about the best covering film for RC planes, and it is a good default for sport models.
Iron-on fabric
Woven iron-on coverings such as Oratex give a fabric look with good puncture resistance, and many can be painted. They tend to cost more than film. Product pages for Oratex describe notable shrinkage and adhesion, and it is sold for model use only, so follow the manufacturer’s guidance for temperatures and preparation.
Dope and fabric
A traditional approach uses fabric glued to the frame and tightened with dope, then painted. It gives an authentic scale finish but takes more time, and the solvents need care. See the dope substitutes article for the alternatives.
Paint and foam
Many foam models are painted or finished with thin tape or film applied at low heat. Foam can be damaged by heat and solvents, so check that any covering is rated for foam.
How to choose
- Light indoor or free-flight: tissue.
- Sport and trainer RC models: iron-on film.
- Scale or vintage appearance: fabric or tissue and dope.
- Foam models: foam-safe film or paint.
- Engine power: check fuel resistance.
Preparing the airframe
- Sand the structure smooth and remove dust.
- Round sharp edges slightly so film does not cut or bridge.
- Fill dents and seal where needed, following the covering maker’s advice.
- Plan your order, covering the underside and smaller surfaces first and the top surfaces last so the final edges are less visible.
Covering with iron-on film
- Cut the film oversize, leaving a margin around the part.
- Peel the backing and lay the film down, then tack it at one point with a covering iron at the temperature the manufacturer recommends.
- Work outwards, smoothing and sealing the edges first, then shrink the open areas with a heat gun or iron, moving steadily.
- Overlap seams by a small amount and seal them thoroughly.
- Go over all edges once more.
Temperatures vary by product, so use the instructions on the roll, and test on scrap. Too much heat can warp light structures and can cause bubbles.
Covering with tissue
- Seal the bare wood to reduce soaking.
- Cut tissue slightly larger than the panel.
- Lay the tissue, smooth it gently, and attach it around the edges with your chosen adhesive.
- Some builders lightly mist the tissue with water so it shrinks taut as it dries.
- Apply a clear coat or sealer, in thin coats, with light sanding between coats if recommended.
Practice on scrap balsa first. Too much dope or sealer can cause a baggy or ballooned surface.
Covering with iron-on fabric
Application is similar to film, with heat used to bond and shrink. Always read the maker’s guidance, because fabric coverings can have specific temperatures and finishing steps. Oratex lists a shrinkage figure in the region of 15 percent, and advises that the fabric is for model applications only.
Cost
Prices change and vary by seller, so check current listings. As a rough guide, film is usually the lower-priced option, tissue is inexpensive per sheet, and iron-on fabric is typically priced noticeably higher than film. Fabric such as Oratex is sold in rolls of several metres, and the price per roll is generally above that of film rolls.
Common problems and fixes
- Wrinkles: reheat gently and smooth with a soft cloth.
- Bubbles: pierce with a pin and reheat.
- Lifting edges: reseal with the iron, checking the temperature.
- Warped parts: usually from overshrinking, so reduce heat and let the part cool in a jig.
- Saggy tissue: ensure you let it dry fully and avoid overapplying dope or sealer.
FAQ
How do I cover a model airplane with tissue?
Seal the wood, lay tissue over the frame, secure the edges with adhesive, shrink lightly with a water mist, and finish with thin coats of sealer or clear.
What are some good covering materials for model aircraft?
Tissue, iron-on film, iron-on fabric and traditional fabric with dope.
How much does Oratex fabric cost?
Prices vary. Oratex is generally priced above standard film and is sold by the roll, so check a current retailer.
What is the best covering film for RC planes?
Many hobbyists use heat-shrink polyester film from established brands. The best choice depends on weight, color and budget.