Repair a Balsa Wood Airplane Model with Super Glue

A great introduction to flying airplane models is the balsa wood models. Balsa wood is the traditional structure material used in flying model airplanes. Incidentally, balsa is actually a hardwood, despite its soft feel, and is perfectly suited for the construction of model airplanes because of its outstanding strength to weight ratio. Balsa wood airplane models are still widely available, with the material coming in several sizes and shapes. In certain parts of a model airplane structure, where more strength is required, like the landing gear plates and engine bulkheads (firewalls), thin model-grade plywood may also be used.

balsa model airplane kits

However, when flying your balsa wood airplane model, it is sometimes inevitable that it will in time suffer some minor damages, like bends, scuffs, and breaks. Your model airplanes can get damaged in a variety of ways, whether at home, in transportation, or from the testing field. You may also be worried about gaps or cracks during or after building. Any damage can be repaired but whether the repair work is worth doing is for you to decide. The balsa wood is fairly easy to work with, owing to its lightness and robustness. In fact, you can repair the cracks or gaps in your balsa wood models by yourself if you already know how to do it. This article will guide you on how to repair any damages to your balsa wood airplane model and get it back on the shelf or in the skies again.

What You Will Need



Some of the model aircraft parts that are likely to suffer damage from time to time include the fuselage, wings, nose bearing, propeller, motor mount, undercarriage parts, and fuel tanks.

Inevitably, you’ll have to use some form of adhesive or glue to repair any damage that your balsa wood models may have received. You need to be well prepared for this eventuality. As such, it’ll be helpful to know what types of adhesives are best for the specific requirements you have. There is a wide range of adhesives types available in the market for repairing balsa wood planes. While they all have a valuable purpose, it would be important for you to know what they bring to the table. The type of glue used will depend on the type of wood and the hardness of the balsa joints, as well as the preference desired.

One of the most commonly used adhesives on balsa to balsa joints, is cyanoacrylate (CA glue), also known as super glue. Super glue is excellent for bonding balsa wood, metals, ceramics, stone, and hard plastics together. Starbond is a high quality super glue company that sells this family of instant adhesives. For balsa wood repair, use medium viscosity super glue.

This medium super glue dries in seconds, and can be used for various projects/repairs around your home. It also comes in many different sizes from as small as 1-ounce to as large as 16-ounces. Always have one of our super glue bottles available by storing it on your shelf in case one of your balsa models ever need repairing.

Medium super glue strikes a balance between the thick and thin types, since it has stronger bonding capabilities to do the job compared to the thin type glues without adding excessive weight as the thicker type glues. You can use medium super glue to harden the threads cut into wood, and for certain types of dissimilar joints like carbon fiber-to-wood. It can also be used to glue difficult-to-clamp items when you don’t want to hold two parts together for the duration another adhesive would take to dry.

Lay a piece of newspaper down on the chosen working surface to protect the table from any excess super glue. Measure the width and length of the gap or crack in your balsa model airplane, then cut a proportionate thin sized thin balsa wood strip from an extra sheet using a craft knife. Sheets of 2 or 3-inches thick of insulating foam make ideal modeling and repair boards. The board needs to be perfectly flat as any twists or lumps in the board can get transferred to your model plane during repair.

To help ensure the balsa wood strip is suitable for the gap or crack, sand the repair strip lightly using fine-grit sandpaper until it fits. You can then clean all sanding dust from the repair balsa strip using a clean cloth after sanding the strip. Use an applicator to apply and glue the repair strip to the gap or crack in the model and wipe off the excess glue from the model using a clean cloth or rag. To hold the repair tight, use the masking tape and then wait about an hour to permit the repair to dry.

While medium super glue will stick most parts together, the quality of the surface is also important. Any grease or dust on the surface will greatly reduce the bonding strength. You should wipe off any excess glue immediately with a paper towel. Any glue residue that was left to harden, scrape off afterwards with a sharp knife. If you notice any ridges of dried glue after you remove the masking tape, use a medium grit sandpaper to sand it away. Examine the repaired model for any remaining imperfections. You can do this by holding the balsa wood model up to the light. Sand any imperfections away using the medium-grit sandpaper, if they are still existent.

Your balsa wood model is finally all repaired and ready to go. All balsa wood used in the repair needs to acclimate to your repair shop before it is used. You should let the sheet of wood sit in the shop for a couple of days after buying before using it. This is to avoid warps because balsa wood swells and shrinks significantly. If your fingers accidentally get bonded together, you can use super glue de-bonder to carefully separate them. It’s important to always have a de-bonder for such incidents if you choose to use super glue.

Where stronger joints are desirable such as engine bulkheads and landing gear plates, then 2-part epoxy resin is common. Fuel tanks can split open on account of defective molding, bad design, poor assembly, or damage from a crash. It’s essential that you coat the fuel tank compartment with something fuel-proof like polyurethane (paint) or epoxy resin. You can use medium super glue on all firewall joints in a Glow/Nitro powered aircraft model since it’s fuel-proof. This precaution isn’t that necessary in electric-powered model aircrafts because the possibility of impregnating the construction with fuel is highly unlikely. Also, don’t use medium super glue for high stress parts and clear plastic areas since the adhesive can fog the plastic.