My Simple Approach to Fairing Repair

Warning: Before you start you need to know that plastics and other compounds found on fairings are toxic and fumes given off during this procedure could be harmful. Protect yourself from fumes (I use a small fan heater blowing cold air) so that you do not inhale any. Also molten plastic will hurt you if you get it on your flesh so wear suitable protective clothing. Remember that cracks that have already had an attempt at repair may contain “super glue” which gives off cyanide gas when heated.

DO NOT attempt to repair covers that have a safety factor in their use, for instance the CHAIN GUARD !! Even though a chain guard can feel pliant and floppy it is made from a different material to decorative fairings that gives it the strength needed to protect you from a broken chain. The joints created here will not be strong enough to ensure safety.

If you are in any doubt then do not do any of the following techniques.

Using the rear cowl from a 1987 SRX400 as an example.

The mounting lug on the rear cowl needed repair on a bike recently purchased.

Clean the area as best you can, getting rid of as much grease as possible.

Loosely attach the broken part with tape. I find that masking tape is better than PVC electrical tape as it doesn’t deform when heated.

If this picture is studied carefully it can be seen that the mounting lug is actually riddled with “age cracks” as well as being broken off the main cowl.

The repair will be made using a standard electrical mains powered soldering iron.

I have a variety of sizes and powers but basically any soldering iron of 25Watts or more costing as little as a fiver is suitable.

Welding

The basic technique you will follow is similar to metal welding and you will create a “puddle” of molten plastic

that spans either side of the crack to a depth of around two thirds the depth of the crack.

It is important that you do not let the plastic burn as charred plastic will not form a strong joint. If this should happen

you will need to cut the charring out with a knife.

Use the iron to press the molten plastic down into the fairing to try and get rid of as much air as possible and form a surface that is as smooth

as possible yet still leaves plastic to be sanded back later.

Try to only melt the top half or two thirds of the crack so that you maintain the shape of the fairing.

Large cracks in panels can be supported from behind if needed,

Many cracks in fairings are “invisible” and if welded carefully (not too deep or too hot a weld) from behind

it can be used without any finishing work done to the “face side” of the fairing.

If adding extra plastic to a weld then try to ensure that you use a similar plastic to the fairing. Examine the fairing panel you are working on for the

re-cycle marks of, typically, PS, ABS or AES. Do not assume that all panels on the bike will be the same. Try to find an old plastic part

from around the house with the same re-cycle identifier (clothes hangers are a good start).

Start by melting some of the plastic around the crack and press the plastic down into the crack.

Make sure that a reasonable amount of plastic is fully melted around the crack, but do not let the plastic burn.

I like to do a few “tacks” to join the part, allowing the tape to be removed, before welding the crack up fully.

Remember to keep trying the part on the bike to make sure you have a good alignment.

Again this picture shows the numerous cracks around the bolt hole if studied carefully.

A simple crack can be repaired just by using the plastic from the part itself.

A larger repair may need extra plastic to be added.

This picture shows how I have repaired the myriad cracks around the mounting lug and added extra plastic

to bring the thickness back above the original layer.

The finished “weld” can look a mess when so much area is to be repaired but if you have built it up

enough then it is a simple job to smooth down and finish.

Finishing

Applying a decorative finish to your panel is relatively easy and is no different to repairs to cars etc.

There are lots of data available from other sources so I’ll just give my method here briefly.

It cannot be emphasised enough that scrimping in the preparation here will lead to a poor finish.

Plastic is relatively hard so I let the joint cool completely and then start to smooth with a bastard file,

moving through two finer grades of file and then onto 60 grade emery.

There will inevitably be small blow holes in the plastic repair, but don’t worry about them.

Now is the time to rub the whole panel down and start preparing for painting.

I use very thin layers of fine ready-mix “scratch filler” and then rub the whole panel down with 600 grade wet-n-dry (used wet)

and then follow on with 1200 grade and finally 1500 grade.

A quick spray over with primer can often reveal imperfections that weren’t visible before – just go back and keep filling and sanding until you have a perfect finish.

Finally let everything dry and wipe clean from all dust etc. then spray using 2 coats of Plastic Primer, leave to harden

and lightly rub down with 1500 wet n dry, and then paint with the paint of your choice.

Many places will match the colour of your bike and supply paint in tins to be used with a separate spray gun or in spray cans for smaller jobs.

Halfords are probably the most accessible place for many people (ask to see the Motorbike colour chart and they mix the paint for you)

but lots of other auto shops do the same.

If you have a metallic finish you must leave the final paint coat to harden for at least 24 hours

before rubbing it back to a matt finish using 1500 grade wet-n-dry paper and then spraying with two coats of lacquer.

Make sure you use a “petrol resistant lacquer” for tanks and related areas.

Allow any lacquer to harden before rubbing back with compound and polishing.

Then refit to the bike !!

Larger cracks are handled in exactly the same way.

If an area has been worn away (or lost) when the fairing was damaged then the hole can be filled

using plastic in the same way as detailed above but it will not be as strong as the original.

In this instance it is better to use a backing piece (e.g. glass fibre) for strength if the area can be hidden from sight.

Remember – the best results come from taking your time. It might sound complicated but if you allow a week of occasional

work in the garage (or kitchen if you are single… or want to be!!!) then professional results can be obtained for very little cost.

All information is given in good faith without guarantee. I would recommend you practice repairing other parts before attempting to repair your own bike (how about smashing a coat hanger and repairing that?). This method may not be the best and is definitely not the only method in use but it has worked for me on numerous occasions.

C. 2004 Mike Thornton