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The fairing is the garment of the bike: it improves its aerodynamics and protects it. But it is fragile and the slightest shock or hitch is seen. Repairing a fairing that is broken, split or scratched by a professional is expensive. It is often possible to save the situation yourself.

Text and photos C. Petitjean

Practical advice

● Do not use white spirit to clean the plastic: it is a greasy product. To ensure a good adhesion of the resin on the support, degrease the latter with acetone or cellulosic diluent.
● If the polyester resins are harmed below 18°, epoxy resins are possible from 10°. It is possible to accelerate the reaction by reheating from a distance using a heat gun, without exceeding a temperature of 40° on the surface of the plastic.

Unfortunately it does not take much to damage an element of the fairing of a motorcycle. But the repair by professionals is done with a specific material and glues adapted to the composition of the plastic. Suffice to say that pure and simple replacement is often the chosen solution, with a cost price accordingly. If the slots are small and there is no shortage of pieces, it is cheaper to fend for yourself.

Plastic and plastic

Motorcycle fairings are made from injected or thermoformed composite plastics in ABS and / or polycarbonate. Only epoxy resins (or epoxy) allow their repair. They can also be used on PVC and glass and carbon fibers. The resin used here is of this type.
● Polyester resins are only suitable for polyester repair. It is associated with fiberglass to give it more resistance. This mixture allows the manufacture of small series or single castings.

The repair

Both products used here are commonly available in large auto accessory areas.
● The first, "Black Colle", is a putty-glue used in "tuning" to assemble plastic elements. It allows here to glue a mudguard with small breaks (it is however not suitable for filling large volumes). The slot is dug and widened, then glued edge to edge while maintaining pressure. After drying, the hollow is filled with adhesive mastic to strengthen the assembly.
● The second product, "Ideas-Fix" is an epoxy resin reinforced with plastic. It allows to clog, repair and assemble all plastics. Bicomponent, it enters chemical reaction by kneading by hand until a homogeneous paste. The surface preparation is the same as before. The paste is then pressed into the groove, and smoothed with a wet finger. Very adherent, it hardens on drying, before being shaped into a rasp.

Finishes

To perfect the surface, a polyester putty (activated by a hardener), is applied in a thin layer, then sanded. The adhesion of the polyester is sufficient for surfacing but does not contribute to the mechanical strength. This would require an epoxy putty, but this product does not exist in finish. To paint the fairing elements, contact a professional. Only he will be able to do a good job.

Open the slot

Open the slot

The front fender is slightly split on one cheek. To promote the penetration of the sealant, open the slot a little with a soldering iron or with a small conical grinding wheel mounted on flexible.

Apply the adhesive sealant

Apply the adhesive sealant

Degrease with acetone. Spread the lips of the crack; coat them with putty-glue, then squeeze the edges for fifteen minutes. Generously fill the bleeding and smooth with a spatula.

Prepare the epoxy resin

Prepare the epoxy resin

The epoxy resin is in the form of a stick. Take a slice with a knife, then knead until you get a uniform color (the resin is beige and the blue hardener).

Repair the lower hoof

Repair the lower hoof

The lower hoof of the fairing is very exposed to shocks, where a slot is important. As before, dig the bleeding, degrease, fill with the paste, then compact with a spatula.

Eliminate excess sealant

Eliminate excess sealant

After polymerization, finish the shaping by removing the excess sealant with the miller's cutter file. Conform the rasp to the curve of the curved parts by acting on the adjusting screw.

Apply the finishing layer

Apply the finishing layer

The finishing coat is made of polyester putty thoroughly mixed with 2% peroxide hardener. Apply to the flexible spatula, extending well over the surface of the repair.

sand down

sand down

After drying, sand at 80 grit, 150 grit, 240 grit and 400 grit. Work dry: the mastic absorbs moisture. Use a sanding block to avoid digging with your fingers.

A clean and smooth surface

A clean and smooth surface

The surface condition of the repaired elements must be clean, without the slightest scratch, otherwise the professional to whom the metallic paintwork will be entrusted will not be able to do clean work.


Video Instruction: How to repair a motorcycle fairing CHEAP!