Guide to Plastic Welding and Painting Motorcycle Fairings

Guide to Plastic Welding and Painting Motorcycle Fairings

When I bought my Ninja 650 to repair, I bought it knowing the engine was fine but that it needed a bunch of cosmetic repairs to the controls, fairing, and seat.

My goal was to get the motorcycle to a condition where it wouldn't be embarrassing, and to where I could take it to a racetrack. At the track, it's possible I'd crash it and have to repair fairings again.

So if you've ever dropped and cracked a fairing, knowing how to plastic weld and repaint a fairing is a valuable skill to know!

After checking out a few YouTube videos and guides I figured out a general process for repairing fairings and wanted to put it here for posterity. Hope it's useful.

You might also like my guide to repairing and re-upholstering a motorcycle seat by re-covering it with vinyl.

What you need to repair motorcycle fairings

This is what you need. Don't cheap out!

  • A disc sander — don't hand sand it! It'll take forever and your hands will be SORE and you'll probably do a terrible job. These are cheap. Get a bunch of sanding discs from 80 grit to (or more)
  • Paint — For a large panel you need half a can of primer, one can of colour, and half a can of clear coat. These are about $5 a can
  • A soldering iron, basic kind, 60W. About $20.
  • A particle mask - get a 3M one that filters out fumes as best as possible
  • Plastic zip ties, probably black, but clear if your fairings are light.

General process for repairing motorcycle fairings

Here are the steps to repairing fairings. This isn't the "perfect" way, but it gets the job done.

  1. Remove the fairing piece from the motorcycle. You can usually do this with a screwdriver and pliers for a few clips.
  2. Clean the fairing with water and a sponge.
  3. Use a soldering iron and cable ties (made of plastic) to solder the plastic shut, making sure to properly melt the plastic together. You need cable ties because you need extra plastic.
  4. Use a body filler putty (generic kind) to fill in the gaps around your soldering work.
  5. Sand the entire panel down. Sand the roughest bits with coarse and then progressively fine sandpaper, ending at about

Soldering fairings

When you solder fairings it's usually quite an ugly job that you'll fix later using sandpaper.

This was my starting point:

hole in motorcycle fairing that needs to be repaired.
Big hole in plastic fairing of Ninja 650

This hole was about the size of my palm. On top of being large, it wouldn't hold together. I think a previous owner had tried to glue it back in place unsuccessfully.

I learned the general principle from the YouTube channel "Delboy's Garage" who demonstrated it on a plastic box.

I didn't take Delboy's suggestion and practise because I have many years experience using a soldering iron already (for electronics). Also, my motorcycle was such a throwaway cheap motorcycle I didn't care too much.

But I'd suggest if you're unfamiliar — or if it's your precious Panigale — practise first! (Also, don't do this on your Panigale! What are you thinking??)

Here are the key points of welding together plastic.

  • Hold the plastic firmly together. I had to use my hand (sometimes knee) to hold the plastic in place, then melt it together at various points.
  • Be generous with the zip/cable ties. It's better to have too much plastic melted into there than not enough.
  • Allow it to be ugly. Strength is much more important than aesthetics. The strength isn't structural (i.e. you won't crash if it pops open) but you'll have undone hours of work!

Repainting fairings after you've repaired them

Once you've soldered fairings back together, you have to repaint it.

There's basically four levels of repainting

  • Touch up paint — will forever look obvious, but it'll be fine if you don't care too much
  • Repaint the panel with rattle cans — will look fine on most sub-$3,000 motorcycles
  • Repaint with a horsehair brush — apparently will look great (better than rattle cans), but I haven't tried it!
  • Repaint it with a compressor, paint guns etc. — do it if you want and you have the gear!

What NOT to do (what I tried)

  • Do not try just re-spraying a portion of the fairing panel. It is really hard to avoid leaving a line. You must either re-spray the whole thing, or nothing.
  • Do not sand the panel with your hand. Use a disc sander! Sanding with your hand takes hours and is messy and it will never be a great job. By the time you're done, you'll have spent so much time that there's no way it's worth your time.

What I did — I resprayed the panel using rattle cans.

For this you need

  1. Sandpaper + a disc sander, up to 2000 grade
  2. Filler putty
  3. A big open area, in the open wind
  4. Three rattle cans — primer, color, and clear coat.
repairing motorcycle weldings - sanding, filler putty
The motorcycle fairing panel, partially sanded

The process

  1. Sand back all the plastic that you added when you were doing plastic welding. Get it vaguely smooth. You can use a coarse grit sandpaper for this.
  2. Add filler putty to the holes (that's the pink stuff in the photo above)
  3. Sand again, this time sanding the whole fairing. Get it coarse. You don't have to remove the paint, but you should at least remove the layer of clearcoat and partially remove the colour.
  4. Sand it smooth to 2000 grit. It needs to be smooth. Paint doesn't fill in scratches.
  5. Apply your primer, then colour, then clearcoat.

I found it best to hold the fairing up on an elevated point, like off a string.

The way you apply 1 coats of paint

  • Spray evenly over the surface once. Don't go thick, or complete - you're going to keep painting in a sec
  • Wait 30 seconds
  • Do the same thing twice over
  • Wait an hour

That's one coat - three "sprays over".

For the primer, do 2 coats. This will use about half a can on a big fairing.

For colour, do 3-4 coats. Then do 2 coats of clear coat.

After that, your fairing should be nice and shiny:

Repairing motorcycle fairings with plastic welding and painting
The repaired Ninja 650 fairing with a new coat of paint

My job is NOT pretty. This was my first time.

What I learned for next time I repair a motorcycle fairing

Here's what I'd do next time (and what you should do)

  • Use a disc sander!
  • Sand back the entire fairing
  • Use regular paint and a fine horsehair brush — I'm really keen to try this to see how well it works!